Article

Changes in three dimensional lumbo-pelvic kinematics and trunk muscle activity with speed and mode of locomotion

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Abstract

Control of the trunk is critical for locomotor efficiency. However, investigations of trunk muscle activity and three-dimensional lumbo-pelvic kinematics during walking and running remain scarce. Gait parameters and three-dimensional lumbo-pelvic kinematics were recorded in seven subjects. Electromyography recordings of abdominal and paraspinal muscles were made using fine-wire and surface electrodes as subjects walked on a treadmill at 1 and 2 ms(-1) and ran at 2, 3, 4 and 5 ms(-1). Kinematic data indicate that the amplitude but not timing of lumbo-pelvic motion changes with locomotor speed. Conversely, a change in locomotor mode is associated with temporal but not spatial adaptation in neuromotor strategy. That is, peak transverse plane lumbo-pelvic rotation occurs at foot strike during walking but prior to foot strike during running. Despite this temporal change, there is a strong correlation between the amplitude of transverse plane lumbo-pelvic rotation and stride length during walking and running. In addition, lumbo-pelvic motion was asymmetrical during all locomotor tasks. Trunk muscle electromyography occurred biphasically in association with foot strike. Transversus abdominis was tonically active with biphasic modulation. Consistent with the kinematic data, electromyography activity of the abdominal muscles and the superficial fibres of multifidus increased with locomotor speed, and timing of peak activity of superficial multifidus and obliquus externus abdominis was modified in association with the temporal adaptation in lumbo-pelvic motion with changes in locomotor mode. These data provide evidence of the association between lumbo-pelvic motion and trunk muscle activity during locomotion at different speeds and modes.

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... Additionally, predictable trunk perturbations are associated with earlier activation of deep versus superficial fascicles of the multifidus (MacDonald et al., 2009;Moseley et al., 2002). Surprisingly, very few studies have investigated either the thoracolumbar spinal posture or paravertebral muscle activity during gait in asymptomatic adults (Lamoth et al., 2004;Lee et al., 2014;Saunders et al., 2004Saunders et al., , 2005Thorstensson et al., 1982), or in adults with back pain (Lamoth et al., 2004(Lamoth et al., , 2006, despite walking being commonly promoted as beneficial in optimising low back health. An improved understanding of the neuromuscular mechanics of the lumbar spine appears necessary to better inform the use of walking as a therapeutic strategy. ...
... Third, we expected differential activity to be demonstrated between deep and superficial multifidus regions in relation to the gait cycle, and fourth, for trunk inclination to increase and lumbar lordosis to consequently accommodate the postural changes needed with increased inclination. Our final hypothesis expected lower limb kinematics to be influenced by walking condition, and in particular ankle, knee, and hip motion to increase with more demanding conditions (Saunders et al., 2005). ...
... In agreement with our findings, increases in the amplitude and relative duration of superficial abdominal and paravertebral muscles are shown with faster gait speeds (Grillner et al., 1978;Lee et al., 2014;Saunders et al., 2004Saunders et al., , 2005Thorstensson et al., 1982). However, our results indicating longer duration of the deep compared to superficial multifidus with increased walking demand, and the time of peak activity differing with varying inclinations, appears to conflict in part with the study most closely aligned with ours methodologically (Saunders et al., 2004). ...
... Lateral bending (LB) of the spine was found to be the main motion direction in bipedal walking (Crosbie et al., 1997b) with a predominantly monophasic motion pattern (Chung et al., 2010;Crosbie et al., 1997b;Fernandes et al., 2016;Leardini et al., 2011;MacWilliams et al., 2014MacWilliams et al., , 2013Romkes and Bracht-Schweizer, 2017;Saunders et al., 2005;Stokes et al., 1989;Syczewska et al., 1999;Thorstensson et al., 1984;Thurston and Harris, 1983;Vogt et al., 2001) (Figs. 2B and 3B). ...
... Mainly the lumbar spine contributes to LB of the trunk (MacWilliams et al., 2014). LB symmetry ranged from highly symmetric around zero (Dalichau et al., 1998;Saunders et al., 2005) to asymmetric, with a strong emphasis to one side, presumably because of pelvic obliquity (Saunders et al., 2005;Whittle and Levine, 1999). During walking, only approximately 13-18% of the maximum total LB RoM are retrieved (Feipel et al., 2001). ...
... Mainly the lumbar spine contributes to LB of the trunk (MacWilliams et al., 2014). LB symmetry ranged from highly symmetric around zero (Dalichau et al., 1998;Saunders et al., 2005) to asymmetric, with a strong emphasis to one side, presumably because of pelvic obliquity (Saunders et al., 2005;Whittle and Levine, 1999). During walking, only approximately 13-18% of the maximum total LB RoM are retrieved (Feipel et al., 2001). ...
Article
Sheep, pigs and goats are the most commonly used large animals for preclinical spinal applications. However, there is an increasing number of voices challenging the suitability of quadrupeds, as the obvious postural differences give reason to presume significant differences in the spinal kinematics compared to humans. Rather, it is often questioned if primates did not represent the more suitable experimental animals due to their ability to bipedal walking. Both perspectives, however, have never been systematically addressed. Therefore, the present paper reviews the existing literature on in vivo spinal kinematics of quadrupeds, primates and humans during walking and critically discusses the comparability between these species. Surprisingly, no studies were found for sheep, pigs or goats. Instead, the literature search yielded 50 studies on quadrupeds, horses (n = 37) and dogs (n = 13), primates (n = 10) and humans (n = 61). In general, the kinematic data revealed a high level of heterogeneity and often demonstrated methodological deficits, e.g., insufficient number of measured animals. More kinematic variables were comparable between humans and quadrupeds than between humans and primates. Differences in spinal characteristics, however, could also be found amongst quadrupeds themselves (horse vs. dog). In conclusion, using of a particular animal species as a model for spine research requires its characterization. Cross-species extrapolations are ineligible. Furthermore, the review revealed significant differences between the bipedal walk of primates and humans. The gait alone thus does not constitute a valid argument for the superiority of primates over quadrupeds as experimental animal models for human spine research.
... Behm et al. [7] observed that a greater activation of the obliquus externus abdominis muscle and erector muscles of the upper and sacral spine is required during running for the control of movements and that the activation pattern of these muscles may be associated with better performance. For this reason, a specific training programme can promote greater stability, which would decrease necessary muscle recruitment and consequently positively affect C met [8,9]. ...
... Therefore, the increase in running speed would cause more lumbopelvic movements and consequently greater instability, which would require greater neuromuscular control to achieve stability during cyclical movements such as running [8,26]. In turn, this increased neuromuscular demand for stabilization of the lumbopelvic region appears to be associated with a greater contribution of concentric activations-which are more energy-consuming than eccentric and isometric activations-and reinforces the fact that an unstable system is also less economical [25,27]. ...
... From this perspective, lumbopelvic stabilization is one of the aims of Pilates. Among its guiding principles, breathing [28] and centring [29] have been shown to stimulate the deep abdominal muscles responsible for stabilization, including the rectus abdominis muscles, OI, OE, and transversus abdominis [8]. In this respect, Phrompaet et al. [30] evaluated the effects of PT in the control of lumbopelvic movements. ...
Article
Full-text available
Purpose Strength training improves distance running economy and performance. This finding is based predominantly on maximal and explosive strength programmes applied to locomotor muscles, particularly on the lower limbs. It is not certain whether a minimization of metabolic cost (Cmet) and an improvement in running performance is feasible with strength training of the postural and trunk muscles. Methods Using kinematic, neuromuscular and metabolic measurements of running at two different speeds before and after a 12-week Pilates training programme, we tested the hypothesis that core training might improve the running Cmet and performance of trained runners. Thirty-two individuals were randomly assigned to the control group (CG, n = 16) or the Pilates group (PG, n = 16). Results Confirming our hypothesis, a significant improvement (p<0.05) was observed for running performance in the PG (pre: 25.65±0.4 min; post: 23.23±0.4 min) compared to the CG (pre: 25.33±0.58 min; post: 24.61±0.52 min). Similarly, the PG (4.33±0.07 J.kg⁻¹.m⁻¹) had better responses than the CG (4.71±0.11 J.kg⁻¹.m⁻¹) during post-training for Cmet. These findings were accompanied by decreased electromyographic activity of the postural muscles at submaximal running intensities in the PG. Conclusions Overall, these results provide a rationale for selecting strength training strategies that target adaptations on specific postural and locomotor muscles for trained distance runners.
... To assist balance and forward progression during walking, particularly as speed increases, persons with LLA laterally flex the trunk toward the prosthetic limb during ipsilateral stance and minimize relative motion between the trunk and pelvis in the axial plane (Esposito and Wilken, 2014;Goujon-Pillet et al., 2008;Hendershot and Wolf, 2014;Jaegers et al., 1995). Able-bodied individuals demonstrate increases in trunk motion and muscle activity as walking speed increases (Anders et al., 2007;Callaghan et al., 1999;Saunders et al., 2005). Similarly, increased trunk motion as a function of walking speed is also observed in persons with LLA (Jaegers et al., 1995). ...
... EMG onsets and offsets were determined by visual inspection (Hodges and Bui, 1996a;Saunders et al., 2005); EMG onset was defined as the first upward deviation in EMG amplitude above baseline levels of activity; EMG offset was determined when the level of EMG activity returned to baseline and remained there for > 5% of the gait cycle (Hodges and Richardson et al., 1999;Saunders et al., 2005). Four reviewers independently analyzed each EMG signal and identified all perceived onsets and offsets of muscle activity within each time series. ...
... EMG onsets and offsets were determined by visual inspection (Hodges and Bui, 1996a;Saunders et al., 2005); EMG onset was defined as the first upward deviation in EMG amplitude above baseline levels of activity; EMG offset was determined when the level of EMG activity returned to baseline and remained there for > 5% of the gait cycle (Hodges and Richardson et al., 1999;Saunders et al., 2005). Four reviewers independently analyzed each EMG signal and identified all perceived onsets and offsets of muscle activity within each time series. ...
Article
Persons with lower limb amputation (LLA) walk with altered trunk-pelvic motions. The underlying trunk muscle activation patterns associated with these motions may provide insight into neuromuscular control strategies post LLA and the increased incidence of low back pain (LBP). Eight males with unilateral LLA and ten able-bodied controls (CTR) walked over ground at 1.0 m/s, 1.3 m/s, 1.6 m/s, and self-selected speeds. Trunk muscle onsets/offsets were determined from electromyographic activity of bilateral thoracic (TES) and lumbar (LES) erector spinae. Trunk-pelvic kinematics were simultaneously recorded. There were no differences in TES onset times between groups; however, LLA demonstrated a second TES onset during mid-to-terminal swing (not seen in CTR), and activation for a larger percentage of the gait cycle. LLA (vs. CTR) demonstrated an earlier onset of LES and activation for a larger percentage of the gait cycle at most speeds. LLA walked with increased frontal plane trunk ROM, and a more in-phase inter-segmental coordination at all speeds. These data collectively suggest that trunk neuromuscular control strategies secondary to LLA are driven by functional needs to generate torque proximally to advance the affected limb during gait, though this strategy may have unintended deleterious consequences such as increasing LBP risk over time.
... Behm et al. [7] observed that a greater activation of the obliquus externus abdominis muscle and erector muscles of the upper and sacral spine is required during running for the control of movements and that the activation pattern of these muscles may be associated with better performance. For this reason, a specific training programme can promote greater stability, which would decrease necessary muscle recruitment and consequently positively affect C met [8,9]. ...
... Therefore, the increase in running speed would cause more lumbopelvic movements and consequently greater instability, which would require greater neuromuscular control to achieve stability during cyclical movements such as running [8,26]. In turn, this increased neuromuscular demand for stabilization of the lumbopelvic region appears to be associated with a greater contribution of concentric activations-which are more energy-consuming than eccentric and isometric activations-and reinforces the fact that an unstable system is also less economical [25,27]. ...
... From this perspective, lumbopelvic stabilization is one of the aims of Pilates. Among its guiding principles, breathing [28] and centring [29] have been shown to stimulate the deep abdominal muscles responsible for stabilization, including the rectus abdominis muscles, OI, OE, and transversus abdominis [8]. In this respect, Phrompaet et al. [30] evaluated the effects of PT in the control of lumbopelvic movements. ...
... Gracovetsky et al. suggested that the movement of the lumbopelvic region may provide the primary drive for locomotive leg movements (Gracovetsky, 1985;Gracovetsky and Iacono, 1987). Recently, it has been revealed that the kinetic behaviour around the lumbopelvic region, which includes anatomically large muscles, has a critical role in running efficiently, along with trunk posture maintenance (Sado et al., 2016;Saunders et al., 2005). Thus, the understanding of the lumbopelvic kinetic demand in running with wide range of velocities would provide practical implications for performance improvement and injury prevention. ...
... However, previous studies (Sado et al., 2016;Seay et al., 2008) have obtained data in lumbopelvic kinetics for a single velocity. Although previous studies (Cappellini, 2006;Saunders et al., 2005) showed the increase in electromyographic (EMG) activities of some lumbopelvic muscles (such as the erector spinae and internal/external oblique) with running velocity increments, these studies are limited to the slow velocity range (<5 m/s). Thus, it remains unclear whether each lumbopelvic torque is required to increase for faster running, especially in the faster velocity range. ...
... When maximal axial rotation torque was observed, it exerted a negative power. Saunders et al. (2005) also observed that the lumbar axial rotator (external and internal oblique) muscles activated eccentrically, decreasing the difference between pelvic and lumbar rotations during slow running. The axial rotator muscles achieved a slightly larger torque than the maximal strength with eccentric contraction during sprinting. ...
Article
Faster running is not performed with proportional increase in all joint torque/work exertions. Although previous studies have investigated lumbopelvic kinetics for a single velocity, it is unclear whether each lumbopelvic torque should increase for faster running. We examined the relationship between running velocity and lumbopelvic kinetics. We calculated the three-dimensional lumbosacral kinetics of 10 male sprinters during steady-state running on a temporary indoor running track at five target velocities: 3.0 (3.20±0.16), 4.5 (4.38±0.18), 6.0 (5.69±0.47), 7.5 (7.30±0.41), and maximal sprinting (9.27±0.36 m/s). The lumbosacral axial rotation torque increased more markedly (from 0.37±0.06 to 1.99±0.46 Nm/kg) than the extension and lateral flexion torques. The increase in the axial rotation torque was larger above 7.30 m/s. Conversely, the extension and lateral flexion torques plateaued when running velocity increased ˃7.30 m/s. Similar results were observed for mechanical work. The results indicate that faster running required larger lumbosacral axial rotation torque. Conversely, the extension and lateral flexion torques were relatively invariant to running velocity above 7 m/s, implying that faster running below 7 m/s might increase the biomechanical loads causing excessive pelvic posterior tilt and excessive pelvic drop which has the potential to cause pain/injury related to lumbopelvic extensors and lateral flexors, whereas these biomechanical loads might not relate with running velocity above 7 m/s.
... When people begin running, the spine rotates appropriately. There has been some research on lumbar spine motion from the 12th thoracic vertebra (T12) to the pelvis during running in healthy participants using 3D motion analysis [1][2][3] . Schache Some elite runners experience low back pain, such as spondylolysis 5) . ...
... An increase in the running speed was compensated by an increase in the extension angles of thoracic and lumbar spine as well as an increase in the rotation angle of lumbar spine during the stance phase. The results of this study are comparable with those of other reports on motion analysis during running [1][2][3][4] . In a previous study, participants extended the spine by 14° and tilted the pelvis anteriorly by 20° during running 4) . ...
... Schache et al. reported that when participants ran at 14.0 3) and 14.4 km/h 2) , the lumbar spine was extended by 15° and 13°, laterally bent by 23° and 19°, and rotated by 24° and 23°, respectively. Saunders et al. reported that when the running speed was changed from 7.2 to 18.0 km/h, participants' lumbar motion changed from 8° to 14° for lateral bending and from 10° to 19° for rotation 1) . It has been reported that the runners incline the pelvis anteriorly, extend the spine 4) , and rotate the lumbar spine 1) to increase the running speed. ...
Article
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[Purpose] We aimed to clarify and compare the changes in thoracic and lumbar spine motion and to elucidate the relationship between hip and lumbar spine motion during running. [Participants and Methods] Seven healthy females were recruited in this study. Hip and spine movement were measured using a 3D motion analysis system when running at 6, 9, and 12 km/h. One-way analysis of variance was used to compare the changes in hip joint and spine angles during running. Correlation coefficient analysis was used to determine the relationship between the hip and lumbar spine angles at right and left toe-offs. [Results] As the running speed increased, the rotation angles of the thoracic and lumbar spine and the extension angles of the lumbar spine and hip joint significantly increased in the late stance phase. Significant positive relationships were observed between hip flexion and lumbar spine extension angles at toe-off when running at 6 and 9 km/h but not when running at 12 km/h. [Conclusion] To increase the running speed, participants increased the rotation angle of spine and the extension angles of the hip joint and lumbar spine during the stance phase. Participants extended the lumbar spine to compensate for the restricted hip motion at toe-off, which could cause stress to the lumbar spine.
... Our data also indicate an ability to modulate this activity according to the postural demands, as supported by the higher trunk muscle activity observed in the Ekso-TM and Ekso-OG walking trials compared to Loko-TM at matched speeds. It is possible that the muscle activity of the trunk below the level of injury is a result of the spinally mediated activation of stretch reflexes in the abdominal muscles due to the inspiratory activity of the diaphragm and changing intra-abdominal pressure [25] or changes in trunk angle during the gait cycle [26]. In this study, in addition to the controlled breathing protocol followed during the MVC [8], we recorded the breathing pattern during the Ekso and Lokomat assisted walking trials and investigated the patterning of trunk muscle activity with respect to the breathing rhythm. ...
... However, we cannot rule out the possibility that trunk muscle activity could have been facilitated by spindlemediated stretch reflexes. For instance, Saunders et al. (2005) showed that RA activity during walking in able-bodied subjects is coupled to extension of the trunk. However, even at the slowest speed they tested (1 m/s), which is at least three times faster than walking speeds in our study, the range of motion in the sagittal plane is very low (1.2°) [26]. ...
... For instance, Saunders et al. (2005) showed that RA activity during walking in able-bodied subjects is coupled to extension of the trunk. However, even at the slowest speed they tested (1 m/s), which is at least three times faster than walking speeds in our study, the range of motion in the sagittal plane is very low (1.2°) [26]. Thus, it is unlikely that the observed muscle activity in our study was modulated by stretch of the trunk muscles. ...
Article
Full-text available
Background The trunk muscles are critical for postural control. Recent neurophysiological studies have revealed sparing of trunk muscle function in individuals with spinal cord injury (SCI) classified with thoracic or cervical motor-complete injuries. These findings raise the possibility for recruiting and retraining this spared trunk function through rehabilitation. Robotic gait training devices may provide a means to promote trunk muscle activation. Thus, the objective of this study was to characterize and compare the activation of the trunk muscles during walking with two robotic gait training devices (Ekso and Lokomat) in people with high thoracic motor-complete SCI. Methods Participants with chronic motor-complete paraplegia performed 3 speed-matched walking conditions: Lokomat-assisted walking, Ekso-assisted walking overground, and Ekso-assisted walking on a treadmill. Surface electromyography (EMG) signals were recorded bilaterally from the rectus abdominis (RA), external oblique (EO), and erector spinae (ES) muscles. Results Greater recruitment of trunk muscle EMG was elicited with Ekso-assisted walking compared to the Lokomat. Similar levels of trunk EMG activation were observed between Ekso overground and Ekso on the treadmill, indicating that differences between Ekso and Lokomat could not be attributed to the use of a hand-held gait aid. The level of trunk EMG activation during Lokomat walking was not different than that recorded during quiescent supine lying. Conclusions Ekso-assisted walking elicits greater activation of trunk muscles compared to Lokomat-assisted walking, even after controlling for the use of hand-held assistive devices. The requirement of the Ekso for lateral weight-shifting in order to activate each step could lead to better postural muscle activation. Electronic supplementary material The online version of this article (10.1186/s12984-018-0453-0) contains supplementary material, which is available to authorized users.
... This activation controls sagittal and frontal plane motion between the trunk and the pelvis [107]. The amplitude of this activity is low, typically less than 20% of maximum voluntary activation for walking [36,108] although this increases to up to 100% of maximum for fast running [108]. Acutely, increased activation during gait may be adaptive if it serves to reduce motion and project pain-sensitive tissues. ...
... This activation controls sagittal and frontal plane motion between the trunk and the pelvis [107]. The amplitude of this activity is low, typically less than 20% of maximum voluntary activation for walking [36,108] although this increases to up to 100% of maximum for fast running [108]. Acutely, increased activation during gait may be adaptive if it serves to reduce motion and project pain-sensitive tissues. ...
... In comparison with the paraspinals, abdominal muscle activity during locomotion is much more variable between individuals and more dependent upon locomotor speed [105,107,108]. This variability within healthy individuals is perhaps due to the redundancy of the abdominal muscle system and likely accounts for the lack of consistent differences in abdominal activation in individuals with LBP in the present review. ...
Preprint
Objective To identify differences in biomechanics during gait in individuals with acute and persistent low back pain compared with back-healthy controls. Design Systematic review Data Sources A search was conducted in PubMed, CINAHL, SPORTDiscus, and PsycINFO in June 2019 and was repeated in December 2020. Eligibility criteria Studies were included if they reported biomechanical characteristics of individuals with and without low back pain during steady-state or perturbed walking and running. Biomechanical data included spatiotemporal, kinematic, kinetic, and electromyography variables. The reporting quality and potential for bias of each study was assessed. Data were pooled where possible to compare the standardized mean differences (SMD) between groups. Results Ninety-seven studies were included. Two studies investigated acute pain and the rest investigated persistent pain. Eight studies investigated running gait. 20% of studies had high reporting quality/low risk of bias. In comparison with back-healthy controls, individuals with persistent low back pain walked more slowly (SMD -0.59 [95% CI -0.77 to -0.42]) and with shorter stride length (-0.38 [-0.60 to -0.16]). There were no differences in the amplitude of motion in the thoracic or lumbar spine, pelvis, or hips in individuals with LBP. During walking, coordination of motion between the thorax and the lumbar spine/pelvis was significantly more in-phase in the LBP groups (-0.60 [-0.90 to -0-.30]), and individuals with LBP exhibited greater amplitude of activation in the paraspinal muscles (0.52 [0.23 to 0.80]). Summary/Conclusion There is moderate to strong evidence that individuals with persistent LBP demonstrate impairments in walking gait compared with back-healthy controls.
... The level of muscle activation of the different abdominal muscles varies according to the activity performed and the intensity of that activity (Saunders et al., 2005). At walking speeds the EO and IO are minimally activated (Saunders et al., 2005). ...
... The level of muscle activation of the different abdominal muscles varies according to the activity performed and the intensity of that activity (Saunders et al., 2005). At walking speeds the EO and IO are minimally activated (Saunders et al., 2005). However, as speed increases to a fast running pace (i.e. in our sprinters), there is distinct activation of these muscles in coordination with an increase in lumbo-pelvic motion (Saunders et al., 2005;Schuermans et al., 2017). ...
... At walking speeds the EO and IO are minimally activated (Saunders et al., 2005). However, as speed increases to a fast running pace (i.e. in our sprinters), there is distinct activation of these muscles in coordination with an increase in lumbo-pelvic motion (Saunders et al., 2005;Schuermans et al., 2017). EO also aids in the control of anterior pelvic tilting that occurs with acceleration of the back swing phase in running (Akuthota et al., 2008). ...
Article
The abdominal muscles are vital in providing core stability for functional movements during most activities. There is a correlation between side asymmetry of these muscles and dysfunction. Thus, the purpose of this study was to evaluate and compare trunk muscle morphology and trunk rotational strength between sprint hurdlers, an asymmetrical sport, and sprinters, a symmetrical sport. Twenty-one trained collegiate sprint hurdlers and sprinters were recruited for the study (Hurdlers: 4M, 7F; Sprinters: 8M, 2F), average age (years) hurdlers: 20 ± 1.2; sprinters: 20.4 ± 1.9, height (cm) hurdlers: 172.6 ± 10.2; sprinters: 181.7 ± 4.5, and weight (kg) hurdlers: 67.6 ± 12.0; sprinters: 73.9 ± 5.6. Using real-time ultrasound, panoramic images of the internal oblique (IO) and external oblique (EO) were obtained at rest and contracted (flexion and rotation) in a seated position for both right and left sides of the trunk. While wearing a specially crafted shoulder harness, participants performed three maximal voluntary trunk rotational contractions (MVC). The three attempts were then averaged to obtain an overall MVC score for trunk rotation strength. Average MVC trunk rotational strength to the right was greater among all participants, p < 0.001. The IO showed greater and significant thickness changes from resting to contracted state than the EO, this was observed in all participants. The IO side asymmetry was significantly different between groups p < 0.01. Hurdlers, involved in a unilaterally demanding sport, exhibited the expected asymmetry in muscle morphology and in trunk rotational strength. Interestingly, sprinters, although involved in a seemingly symmetrical sport, also exhibited asymmetrical trunk morphology and trunk rotational strength.
... [8][9][10][12][13][14][15][16][17][18][19] or studies examining young adults . [10,[20][21][22][23][24][25][26]. One study reported an incremental reduction in co-activation of the trunk muscles with age, and increased coactivation with gait speed [10]. ...
... While an early report suggested a differential fibre type distribution within multifidus [31], it is contemporarily held that the regional distribution of fibre types is consistent among the posterior paravertebral muscles [32]. Intramuscular EMG (iEMG) studies examining sagittal plane motion showed differential activation within multifidus [23,26,33], with similar potential for the thoracolumbar erector spinae [34][35][36]. However, voluntary differential activation is challenging for many people [37,38] and it is unclear whether differential activation of the spinal muscles can be integrated into rehabilitation. ...
Article
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The influence of age on spinal muscle activation patterns and its relation to kinematics is poorly understood. We aimed at understanding age-related changes to spine and trunk muscle activity in addition to spinal and lower limb kinematics during treadmill walking under various conditions. An observational study was conducted evaluating asymptomatic young (n = 10; 3F, 7M; 26.3±2.5yrs) and older (n = 9; 3F, 6M; 67.1±4.2yrs) adults’ treadmill walking at 2km/h and 4km/h, each at 0, 1, 5, and 10% inclination. Unilateral (right side) electromyography (EMG) was recorded from deep and superficial multifidus (intramuscular) and erector spinae and abdominal obliques (surface); trunk and leg kinematics were also measured. Muscle activity was characterised by peak amplitude and duration of activity, and the time-point of peak amplitude in the gait cycle (0–100%). Peak activation in older adults was lower for the superficial multifidus (p<0.0001) and higher for the thoracolumbar (p<0.001) and lumbar erector spinae (p<0.01). The duration of activation was longer in older adults for all muscles (p<0.05) except the superficial multifidus, and longer during faster walking for all participants. The time-point of peak amplitude in the gait cycle was earlier in older participants for the external obliques (p<0.05). Walking speed appeared to influence muscle activity more than inclination. Older adults used less spine, trunk and lower limb motion, except at the ankle. Age-related differences within multifidus and between paravertebral and trunk muscles were inconsistent. Walking at 4km/h at 5–10% inclination may specifically target the lumbar paravertebral muscles.
... Abdominal oblique muscles participate in trunk rotation control. 31,32 Generally, it is known that abdominal muscles provide stability of the lumbo-pelvic complex; especially the role of transversus abdominis (TrA) is underlined. 33 TrA is able to control mobility of vertebral segments, but it is incapable of controlling global trunk motions. ...
... 33 TrA is able to control mobility of vertebral segments, but it is incapable of controlling global trunk motions. 31,33 During asymmetric motions of an upper limb (i.e. ball serving), trunk rotation in the direction of the moving limb is observed. ...
Article
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Introduction Low back pain (LBP) is a common problem in sports. There is high risk for back pain occurrence in athletes. The knowledge about LBP in overhead athletes is limited. The Movement System (MS) approach is based on association of symptoms and incorrect movements of the spine. The main goal is to identify the localization and direction of improper movements and to restore appropriate motor control of the movement pattern. Aim To present functional evaluation and therapeutic approach based on the MS in the case of LBP in overhead athlete. Case study The study presents a 26-year-old overhead athlete with chronic mechanical LBP, which is related to his sports activity. He reported exacerbation incidents, which had eliminated him from physical activity. Results and discussion Physical examination of the patient had shown deficit of lumbar motor control in directions of extension and rotation of pelvis coupled with functional alterations in muscles. These movements were associated with pain symptoms. The patient had undergone a 4-month-lenght-therapy program, which was focused on spine motor control training and functional reeducation of muscles. A subsequent examination showed an improvement in motor control of the movement and considerable decrease of pain symptoms. Conclusions (1) The MS approach allows to identify the incorrect movement and to relate it with pain symptoms. (2) Reeducation of motor control based on movement system evaluation allows decreasing pain symptoms.
... There are some reports for measuring spine movement of AIS using motion analysis during trunk motion with standing positon [3][4][5] and gait 6,7) . With increasing the running speed, the movement of lumbar spine was increased to extend, laterally bend, and rotate in healthy runners [8][9][10] . However, there were no reports for measuring 3D movement of spine in AIS during running. ...
... However, this runner also bent the thoracic spine to the right and the lumbar spine to the left during the left stance phase, leading to the correction of the convex curvature of the spine. Comparison with healthy runners [8][9][10] , the participant increased the convex curvature of spine during right stance phase. To prevent the degeneration of spine alignment, attention must be paid to the phase wherein the convex curvature of the spine increases. ...
Article
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[Purpose] The aim of this study was to analyze changes in thoracic and lumbar spinal motions during running in a female athlete with scoliosis. [Participant and Methods] A female with scoliosis who was a member of a college track team was recruited for this study. On 1.5-T magnetic resonance imaging, angles between bodies of adjacent vertebrae in the frontal plane were calculated. We measured real-time spine movement while running using a three-dimensional motion analysis system, wherein the running speed was altered (6, 9, and 12 km/h). [Results] We observed a Cobb angle of 29.0° and the right convex curvature of the thoracolumbar spine on magnetic resonance imaging. As the running speed increased, during the right stance phase, the participant increased the lateral bending angle of the thoracic spine to the left and the lumbar spine to the right. However, during the left stance phase, the runner bent the thoracic spine to the right and the lumbar spine to the left, indicating a decreased convex curvature of the spine. [Conclusion] As the running speed increased, the convex curvature of the spine was corrected during the left stance phase but was uncorrected during the right stance phase.
... Within the torso, the spine is composed of 24 articulating vertebrae. In the young, healthy population, sagittal, transverse, and frontal inter-segmental motions of the torso are common in the lumbar and thoracic regions during activities of daily living (Johnson et al., 2010;Saunders, Schache, Rath, & Hodges, 2005). During normal activities, range of motion is likely modulated to meet the demands of the task and the environment. ...
... During normal activities, range of motion is likely modulated to meet the demands of the task and the environment. For example, during gait, transverse motion between the lumbar region and pelvis increases with stride length and during running compared to walking (Saunders et al., 2005). ...
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Objective: The aim of this research was to assess how changing the orientation of the head to the trunk would impact the mobility and coordination of multiple torso segments during a common postural transition. Background: The dynamic relationship of the head to the trunk has a major impact on vestibular, visual, and neck muscle stretch receptor sensory feedback. Integration of sensory feedback is necessary to regulate postural control, which is necessary for the performance of daily and occupational activities. During upright stance, head extension induces postural sway (Vuillerme & Rougier, 2005); however, postural control within the torso may also be impacted. Methods: Eleven male and thirteen female, healthy, young subjects performed the sit-to-stand movement starting from standardized sitting conditions. Each subject performed four sit-to-stand trials with each of three different head orientations: extended, flexed, and neutral. 3-D kinematic data were analyzed for six torso segments: head, cervical, upper-thoracic, mid-thoracic, lumbar, and pelvis. Sagittal range of motion was calculated for torso joints composed of adjacent segment pairs. Cross correlations and time lag to maximum cross correlation were analyzed for all possible pairs of torso segments for normalized sit-to-stand trials. Results: Moving from sitting to standing elicited greater range of motion of most torso joints with the head extended compared to with the head flexed or neutral. Cross correlations at zero lag and maximum cross correlations for most torso segment pairs were lower with the head extended compared to flexed or neutral. The lag to maximum cross correlation was higher for all non-adjacent torso segments with the head extended compared to flexed or neutral. Conclusion: Extending the head on the trunk increased mobility within the trunk and decreased temporal coordination between multiple torso segments. These findings suggest that changing the relationship of the head to the trunk induces postural instability within the torso in a healthy population during a postural transition. Application: Increased mobility and reduced stability within the torso during postural transitions could increase occupational risk for falls and injuries, such as low back pain. Avoiding unnecessary head extension could decrease the likelihood of postural instability and subsequent injury risk.
... To date, several reports have suggested that the torque promoting the pelvic rotation is exerted at the lumbar-pelvic region during running. Schache et al. (2002) found that the lumbar spine rotated toward the free leg side prior to pelvic rotation during slow running, and Saunders, Schache, Rath and Hodges (2005) demonstrated that the obliquus externus and internus abdominis muscles were activated to reduce the difference between pelvic and lumbar rotation during running. From these reports, the rotator muscles around the lumbar/ pelvic region were expected to promote the pelvic rotation toward the free leg side. ...
... A consistent finding across previous studies has been the exertion of lumbosacral torsional torque to promote pelvic rotation prior to the recovery phase during slow running. Additionally, Saunders et al. (2005) found that the magnitude of muscle activity increased as running velocity increased (from 3.0 to 5.0 m/s). Therefore, during sprinting, it has been assumed that lumbosacral torsional torque also promotes pelvic rotation prior to the recovery phase. ...
Article
The purpose of this study was to investigate the effect of lumbosacral kinetics on sprinting. Twelve male sprinters performed 50 m sprints at maximal effort. Kinematic and ground reaction force data were recorded at approximately 40 m from sprint commencement. A whole-body inverse dynamics approach was applied to calculate joint forces and torques at the hip and lumbosacral joints. The contribution of the hips and lumbosacral joint torques to pelvic rotation was subsequently calculated, with joint force powers indicating the rate of mechanical energy transfer between segments across joint centres calculated for both hip joints. The kinetic analysis indicated that the lumbosacral torsional torque contributed significantly to pelvic rotation. Additionally, the pelvic rotation exerted anterior– posterior joint forces on the hips, contributing to the large positive joint force power at the hip of the stance leg. These hip joint force powers assisted in motion recovery during sprinting. In conclusion, the lumbosacral torsional torque might contribute to the recovery motion in sprinting through application of the anterior–posterior joint forces at the hip joints via pelvic rotation.
... In Studien von Saunders et al. (2005) (Beneke & Hütler, 2005). Die Stützzeiten wurden mit einer eindimensionalen Dynamometrie ermittelt, die auch Grundlage für die Schätzung der Beinsteifigkeit nach Morin et al. (2005) war. ...
... Die deutlichste Veränderung zeigt sich in der Lateralflexion, was als Ausdruck einer verbesserten seitlichen Stabilisierung der Hüfte in der Stützphase und somit einer besseren laufspezifischen Rumpffähigkeit interpretiert werden könnte. Da diese als solche jedoch nicht erfasst wurde, sollten in weiteren Studien kinematische Analysen integriert werden (Saunders et al., 2005). ...
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The purpose of the study is the development and evaluation of a running specific core training in youth distance runners. The author supposes that a core training based on the specific requirements of the core muscles while running has a positive effect on determining factors of the running performance (e.g. leg stiffness, running economy). The results show a significant improvement of the core strength (lateral flexion) and the leg stiffness during the intervention. Compared to a reference group there are no significant differences in the development of the leg stiffness, contact time and running economy. Zusammenfassung Das Ziel der Studie ist die Erarbeitung und Evaluation eines laufspezifischen Rumpftrainings bei Nachwuchsläufern. Es wird erwartet, dass sich durch eine auf die Anforderungen der Rumpfmuskulatur beim Laufen ausgerichtete Intervention ein positiver Einfluss auf die Leistungsfaktoren (u. a. Beinsteifigkeit, Laufökonomie) zeigt. Die Ergebnisse deuten auf eine signifikante Steigerung der Rumpfkraft der Lateralflexoren sowie eine tendenzielle Steigerung der Beinsteifigkeit innerhalb des Interventionszeitraums hin. Im Vergleich zu einer Referenzgruppe zeigen sich keine statistisch bedeutsamen Unterschiede in der Entwicklung der Beinsteifigkeit, der Stützzeit und der Laufökonomie.
... During running, lumbar flexion has been shown to dominate the initial loading phase of stance followed by more extension from midstance to toe-off. (Saunders, Schache, Rath, & Hodges, 2005;Schache, Blanch, Rath, Wrigley, & Bennell, 2002;Schache, Blanch, Rath, Wrigley, & Bennell, 2005;Schache, et al., 2001) Lumbar flexion during the initial loading phase is thought to aid in the attenuation of the impact forces. ...
Article
Objectives: To investigate the changes in lumbar kinematic and paraspinal muscle activation before, during, and after a 4-week minimalist running training. Design: Prospective cohort study. Setting: University research laboratory. Participants: Seventeen habitually shod recreational runners who run 10-50 km per week. Main outcome measures: During stance phases of running, sagittal lumbar kinematics was recorded using an electrogoniometer, and activities of the lumbar paraspinal muscles were assessed by electromyography. Runners were asked to run at a prescribed speed (3.1 m/s) and a self-selected speed. Results: For the 3.1 m/s running speed, significant differences were found in the calculated mean lumbar posture (p = 0.001) during the stance phase, including a more extended lumbar posture after minimalist running training. A significant reduction in the contralateral lumbar paraspinal muscle activation was also observed (p = 0.039). For the preferred running speed, similar findings of a more extended lumbar posture (p = 0.002) and a reduction in contralateral lumbar paraspinal muscle activation (p = 0.047) were observed. Conclusion: A 4-week minimalist running training program produced significant changes in lumbar biomechanics during running. Specifically, runners adopted a more extended lumbar posture and reduced lumbar paraspinal muscle activation. These findings may have clinical implications for treating individuals with running-related lower back pain.
... Em geral, os estudos biomecânicos que envolvem a locomoção restringem-se a analisar isoladamente estruturas do membro inferior (6,7,8,9), da pélvis e da coluna vertebral (10,11,12,13,14,15). ...
... it was expected that the strength of the lumbar extensor would be particularly important to maintain the posture. Saunders et al. (2005) investigated the lumbar-pelvic movement while running at a velocity of 3.0-5.0 m/s and revealed that the lumbar spine flexed relative to pelvis in mid-stance followed by extension; moreover, this flexionextension angular displacement increased with the increase in running velocity. ...
Article
The purpose of the current study was to investigate the mechanism of the maintenance of sagittal trunk posture in maximal sprint running. Twelve male sprinters performed 50-m sprint running with maximal effort. Kinematic and ground reaction force data were collected at approximately 40 m from the starting point. An inverse dynamics approach was applied to calculate joint forces and torques at the hip and lumbosacral joints. The pelvic anterior-posterior tilt components from hip extension torque and from the moment of hip joint force were calculated. The lumbosacral extension torque was greater than lumbosacral lateral flexion and torsional rotation torque during stance phase. The first and second peak values of the lumbosacral extension torque were 6.58 ± 1.58 Nm/kg and 3.11 ± 0.76 Nm/kg, respectively. The mechanical load to flex the lumbar region was due to hip extensor, and the posture was not affected by the impact force via the supporting leg. The large lumbosacral extension torque was exerted to maintain the posture while resisting this mechanical load by hip extensor. These findings suggested that lumbar extensor were instantaneously required to exert maximal torque, and sprinters needed to strengthen the lumbar extensor to decrease the load on tissues around the spine.
... The human pelvis has evolved over 4.5 million years to meet the mechanical demands of bipedal locomotion and provides a robust skeletal structure that maximizes muscle lever arms, while minimizing mechanical load for energetically efficient upright locomotion (Stern et al., 1983;Rak, 1991;Lovejoy, 2005;Gruss, 2015). In addition, the coordinated movements of the pelvis, torso, and lower limbs have led to complex, yet coordinated movements during unobstructed locomotion (Saunders et al., 2005;Franz et al., 2009). These movement patterns become more complex as individuals encounter obstacles or negotiate uneven terrain (Wang, 2003). ...
Article
Biomechanics of unobstructed locomotion consists of synchronized complex movements of the pelvis, torso, and lower limbs. These movement patterns become more complex as individuals encounter obstacles or negotiate uneven terrain. To date, limited research has explored how specifically the pelvis, torso, and lower limb segments relate to obstacle negotiation of varying sized objects combined with temporal constraints to perform the task. Understanding pelvis and adjoining segment movements during object negotiation will provide necessary information in identifying abnormal mechanics and potential fall risk characteristics in balance compromised patient populations. In this prospective cohort study, we aimed to compare pelvic, torso, and lower limb kinematics during unobstructed locomotion with obstacle negotiation of varying heights. Ten healthy young adults (7 females and 3 males, mean age 28.4???4.1 years, mean body mass index 22.5???3.6 kg/m2) enrolled in this study. Analysis of within-subject differences revealed a significant increase in sagittal (posterior tilt) and frontal (ipsilateral hike) plane pelvic angular displacement and higher sagittal plane posterior torso lean angular displacement with increased obstacle height. Furthermore, both sagittal plane hip and knee maximum joint flexion were significantly higher with increasing heights of the obstacles during negotiation. These data provide insight on segment mechanics within a non-mobility-impaired population; therefore, providing a baseline to understand the kinematic demands necessary for safe and effective gait in mobility-compromised populations. Anat Rec, 300:732?738, 2017.
... Previous studies analysing the kinematics of the spine during running have tended to define either one or two rigid functional units: a lumbar segment ) and a thoracic segment . Using this approach it has been possible to understand how spinal motion is coordinated with pelvic movement Saunders et al., 2005;. Studies investigating lumbar movement have used either a rigid wand, mounted over a single lumbar vertebrae, or alternatively a set of skin-mounted makers placed across the lumbar region (Seay et al., 2008). ...
Article
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A protocol for tracking the motion of the lumbar spine, which uses seven skin mounted markers, has been adopted in previous studies investigating running. However, this configuration of can be difficult to track with passive motion capture systems. This study therefore investigated whether a four-marker configuration could accurately reproduce the pose of the lumbar spine obtained using the seven-marker configuration. The study also investigated two methods of tracking the thorax. The first method consisted of markers attached to the sterum and the second used two markers placed bilaterally over the acromioclavicular joints and another on the posterior thoracic spine. Kinematic data was collect for n=15 male subjects and the pose, calculated using the different tracking configurations, compared for both the lumbar spine and thoracic spine. The results demonstrated a good match between two lumbar tracking marker sets. However, there was considerable difference between the two thoracic markers sets which was likely due to movement of the arms influencing the pose of the thorax. We therefore recommend the use of four makers to track the motion of the lumbar spine and a rigid plate, mounted at the top of the sternum, to track motion of the thoracic spine during running.
... [5][6][7][8] however, the upper (thorax) and lower (pelvis) parts of the trunk move individually as illustrated by studies of three-dimensional thoracic and pelvic movements during running. 3,[12][13][14][15] With the exception of the block-clearing phase, only the kinematics of the pelvis at the initial acceleration during sprinting have been reported. 16 debaere et al. revealed that the pelvic tilt at the 1st and 2nd steps after clearing the blocks was almost the same as during running; that is, tilting backward during the early support phase and T he trunk is a key structure involved in locomotion. 1 in contrast to steady speed sprinting that show stable upright trunk posture, [2][3][4][5] there is a substantial and step-to-step change in trunk posture in the sagittal plane from the crouched to upright positions during maximal accelerated sprinting. ...
Article
Background: This study aimed to describe changes in thoracic and pelvic movements during the acceleration phase of maximal sprinting, and to clarify which kinematic variable relates to better accelerated sprinting performance. Methods: Twelve male sprinters performed 60-m sprints, during which three-dimensional step-to-step changes in thoracic and pelvic angles, as well as the trunk quasi-joint angle, were obtained throughout a 50-m distance. Results: The patterns of thoracic and pelvic movements were maintained throughout the entire acceleration phase, although the phase profiles of the relative movements between the thorax and pelvis in three planes differed. Increase in peak thoracic and pelvic tilt angles terminated (-10.3° and 3.2° from the vertical line) and trunk extension range (≈21.7°) decreased from the 13th-15th steps. Moreover, thoracic and pelvic obliquity angles decreased from 15.3° and 8.8°, and conversely, rotation angles increased to 23.5° and plateaued (≈16°), during the entire acceleration phase. Moreover, smaller inclination of the thorax and deeper inclination of the pelvis, smaller rotations of the pelvis and trunk quasi-joint and greater thoracic obliquity during the initial section (to the 4th step), deeper inclination of the pelvis during the middle section (to the 14th step), and smaller trunk torsion and thoracic obliquity during the final section in the entire acceleration phase of sprinting were associated with increases in running speed. Conclusions: The results suggest that sprint acceleration toward maximal speed is not performed with only proportional increases in magnitudes of trunk movements, and important factors for better sprint acceleration performance alter with increasing running speed.
... The pelvis is connected with the lower limbs through the hip joints, and with the HAT through the spine, comprising multiple vertebral joints (see figure 5(A)). During walking the pelvis shows a complex three-dimensional continuous motion (Saunders et al 2005). ...
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This review paper provides a synthetic yet critical overview of the key biomechanical principles of human bipedal walking and their current implementation in robotic platforms. We describe the functional role of human joints, addressing in particular the relevance of the compliant properties of the different degrees of freedom throughout the gait cycle. We focused on three basic functional units involved in locomotion, i.e. the ankle–foot complex, the knee, and the hip–pelvis complex, and their relevance to whole-body performance. We present an extensive review of the current implementations of these mechanisms into robotic platforms, discussing their potentialities and limitations from the functional and energetic perspectives. We specifically targeted humanoid robots, but also revised evidence from the field of lower-limb prosthetics, which presents innovative solutions still unexploited in the current humanoids. Finally, we identified the main critical aspects of the process of translating human principles into actual machines, providing a number of relevant challenges that should be addressed in future research.
... With regard to potential limitations, it was assumed that elite racewalkers would be symmetrical as their well-trained gait has been found to show low asymmetry for the most important kinematic variables across racewalking speeds (Tucker and Hanley, 2020). All EMG data in the present study were collected for the right side only, in line with other studies that have measured muscle activity of the right lower limb in elite racewalkers and normal walking and running (Saunders et al., 2005). An alternative approach might have been to pool left and right side data together. ...
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Running technique has been analyzed since antiquity, and yet the study of gait biomechanics is continually developing and unearthing new insights. This is undoubtedly linked to the great variety of skills required in the running and race walking events, despite their apparent simplicity: a fast but fair sprint start, safe and effective hurdle clearances, negotiation of the tight bends in indoor racing, and coping with changes in gradient in road and cross country running are just a few examples. Increasingly, coaches and governing bodies are looking to sports science to help improve their best athletes and raise participation rates in recreational sport, and need a comprehensive resource on technique, performance and training. Regardless of their standard, competitive athletes strive to improve performance and reduce the risk of injury, and biomechanists are ideally placed to support athletes and coaches in this universal sport.
... These investigations have shown that high-speed walking increased EMG amplitudes of muscles in the trunk and lower limbs. [7][8][9][10][11][12] The present data are consistent with previous findings, showing the feasibility of our newly developed system for the dynamic analysis of gait kinematics and the activity of trunk and lower limb muscles in healthy individuals. We developed our original method of analysis to measure 3D gait motion and surface EMG synchronously to evaluate dynamic change of kinematics and myoelectric activity accurately. ...
Article
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Purpose:: To evaluate a newly developed system for dynamic analysis of gait kinematics and muscle activity. Methods:: We recruited 10 healthy men into this study. Analyses of three-dimensional motion and wireless surface electromyogram (EMG) were integrated to achieve synchronous measurement. The participants walked continuously for 10 min under two conditions: comfortable and quick pace. Outcome measures were joint angles of the lower limbs determined from reflective markers and myoelectric activity of trunk and lower limbs determined from EMG sensors, comparing comfortable and quick gait pace. Results:: Lower limb joint angle was significantly greater at the quick pace (maximum flexion of the hip joint: 4.1°, maximum extension of hip joint: 2.3°, and maximum flexion of the knee joint while standing: 7.4°). The period of maximum flexion of the ankle joint during a walking cycle was 2.5% longer at a quick pace. EMG amplitudes of all trunk muscles significantly increased during the period of support by two legs (cervical paraspinal: 55.1%, latissimus dorsi: 31.3%, and erector spinae: 32.6%). EMG amplitudes of quadriceps, femoral biceps, and tibialis anterior increased significantly by 223%, 60.9%, and 67.4%, respectively, between the periods of heel contact and loading response. EMG amplitude of the gastrocnemius significantly increased by 102% during the heel-off period. Conclusion:: Our gait analysis synchronizing three-dimensional motion and wireless surface EMG successfully visualized dynamic changes in lower limb joint angles and activity of trunk and lower limb muscles induced by various walking speeds.
... It is thought that our results were statistically significant due to this gamification factor. Higher running speed results in increased lumbopelvic movements, thus increased instability, and this needs increased neuromuscular control to attain stability while performing cyclical movements, such as running (England and Granata 2007;Saunders et al., 2005). In our study, a statistically significant result was found at ESR test scores the Pilates group. ...
Article
Background Inactivity is a public health problem. Physical activity is beneficial at any age, but is even more critical in childhood for healthy development and growth. Objectives The purpose of this non-randomized controlled study was to investigate the effects of Pilates on posture and physical fitness parameters in 5–6 years old healthy children. Methods Four preschool classes were divided into two groups. Five-six years old 66 preschool children were assigned to the Pilates (n = 31) and control (n = 35) groups. The Pilates group received a Pilates program twice a week for 10 weeks. The control group continued their daily routines. Postural assessment was evaluated using the New York Posture Rating Chart test and physical fitness was evaluated with the Eurofit test battery. Children were blinded to assignment. The Mann-Whitney U test was used for comparisons between groups, and the Wilcoxon Signed-Rank test was used for within-group comparisons. Results In this study, within-group comparisons showed statistically significant improvements in the New York Posture Rating chart test (p < 0.001), Flamingo Balance, Sit and Reach, Standing Broad Jump, 30-Second Sit-Up, Bent Arm Hang, and 20-Meter Shuttle Run test scores (p < 0.05). Conclusion Pilates has positive effects on physical fitness parameters and postural evaluation in preschool children. This study suggests that Pilates can be an entertaining alternative physical activity in children aged 5–6 years. Clinicaltrials.number NCT05210426.
... Although the trunk inclination is a variable that has received little attention in the literature, it is to highlight that the increase in trunk flexion is a natural movement given the increase in speed [6]. The progression to faster running speeds is associated with increases in electromyographic activity, especially in the multifidus muscle, and kinematic changes [32]. However, MF showed different results, because the greatest trunk inclination was observed between 7 and 14 km/h, which implies that postural demands of the MF players differ from the rest of the playing positions. ...
Article
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The development of wearable sensors has allowed the analysis of trunk kinematics in match play, which is necessary for a better understanding of the postural demands of the players. The aims of this study were to analyze the postural demands of professional soccer players by playing position. A longitudinal study for 13 consecutive microcycles, which included one match per microcycle, was conducted. Wearable sensors with inertial measurement units were used to collect the percentage (%) of playing time spent and G-forces experienced in different trunk inclinations and the inclination required for different speeds thresholds. The inclination zone had a significant effect on the time percentage spent on each zone (p < 0.001, partial eta-squared (ηp 2 = 0.85) and the G-forces experienced by the players (p < 0.001, ηp 2 = 0.24). Additionally, a significant effect of the speed variable on the trunk inclination zones was found, since trunk flexion increased with greater speeds (p < 0.001; ηp 2 = 0.73), except for midfielders. The players spent most of the time in trunk flexion between 20 • and 40 • ; the greatest G-forces were observed in trunk extension zones between 0 • and 30 • , and a linear relationship between trunk inclination and speed was found. This study presents a new approach for the analysis of players' performance. Given the large volumes of trunk flexion and the interaction of playing position, coaches are recommended to incorporate position-specific training drills aimed to properly prepare the players for the perception-action demands (i.e., visual exploration and decision-making) of the match, as well as trunk strength exercises and other compensatory strategies before and after the match.
... The vital activity of ES in the control of locomotor patterns has been highlighted by EMG during different rhythmic motor tasks [60,61]. During FW in gait initiation, activation of ES occurs on the swing leg side [12], while it occurs around the double support phase during forward walking [62]. ...
Article
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Background: The use of rehabilitation protocols carried out in water has been progressively increasing due to the favorable physical properties of the water. Electromyography allows one to register muscle activity even under water. Aim: To compare muscle activity between two groups (healthy young adults (HYA) and healthy older adults (HOA)) in two different environments (dry land and aquatic) using surface electromyography during the execution of four different test/functional movements. Methods: Analytical cross-sectional study. HYA and HOA carried out four functional tasks (Step Up and Down, Sit To Stand test, Gait Initiation and Turns During Gait) in two different environments (dry land and aquatic). Absolute and relative muscle activation was compared between each group and between each environment. In addition, the stability of the measured was calculated through a test-retest (ICC 2:1). Results: Within the same environment there were significant differences between young and older adults in three of the four functional tasks. In contrast, in the gait initiation, hardly any significant differences were found between the two groups analysed, except for the soleus and the anterior tibial. Measurement stability ranged from good to excellent. Conclusions: Level of the musculature involvement presents an entirely different distribution when the test/functional task is performed on dry land or in water. There are differences both in the relative activation of the musculature and in the distribution of the partition of the muscles comparing older and young adults within the same environment.
... However, further research is needed to investigate this relationship, which may indeed be epiphenomenal. On the other hand, pelvic tilt is highly correlated to gait speed, and its increased range of motion would indicate greater fore/aft balance [23]. The inclusion of knee flexion/extension is expected as this joint has long been believed a key contributor of functional activities including walking [24]. ...
Article
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Background: While therapy is an important part of the recovery process, there is a lack of quantitative data detailing the "dosage" of therapy received due to the limitations on in/outpatient accessibility and mobility. Advances in wearable sensor technology have allowed us to obtain an unprecedented glimpse into joint-level kinematics in an unobtrusive manner. The objective of this observational longitudinal pilot study was to evaluate the relations between lower body joint kinematics during therapy and functional gait recovery over the first three months after stroke. Methods: Six individuals with subacute stroke (< 1 month) were monitored for a total of 59 one-hour physical therapy sessions including gait and non-gait activities. Participants donned a heart rate monitor and an inertial motion capture system to measure full lower body joint kinematics during each therapy session. Linear mixed regression models were used to examine relations between functional gait recovery (speed) and activity features including total joint displacements, defined as amount of motion (AoM), step number, change in heart rate (∆HR), and types of tasks performed. Results: All activity features including AoM, step number, types of tasks performed (all p < 0.01), and ∆HR (p < 0.05) showed strong associations with gait speed. However, AoM (R2 = 32.1%) revealed the greatest explained variance followed by step number (R2 = 14.1%), types of tasks performed (R2 = 8.0%) and ∆HR (R2 = 5.8%). These relations included both gait and non-gait tasks. Contrary to our expectations, we did not observe a greater relation of functional recovery to motion in the impaired limb (R2 = 27.8%) compared to the unimpaired limb (R2 = 32.9%). Conclusions: This proof-of-concept study shows that recording joint kinematics during gait therapy longitudinally after stroke is feasible and yields important information for the recovery process. These initial results suggest that compared to step number, more holistic outcome measures such as joint motions may be more informative and help elucidate the dosage of therapy.
... Our results agree with the previous studies that demonstrated a relationship between the CSA of the RA and the 6 min walk test in elderly persons (Saunders et al., 2004;Shahtahmassebi et al., 2017). Given that it has been observed that the abdominal muscles are gradually recruited during increasing locomotion speed (Saunders et al., 2004;2005), the muscle would therefore contribute to high-speed locomotion. These results imply that the preservation of the trunk muscle size may also be an important factor to prevent LS. ...
Article
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Although locomotive syndrome (LS) is a condition of reduced mobility, little information is available regarding the loss of site-specific skeletal muscle mass. The aim of the present study is to examine site-specific muscle loss in elderly males with LS. A total of 100 men ranging in age from 65 to 74 years were divided into two groups (LS and non-LS) using LS risk tests including the stand-up test, two-step test, and the 25-question geriatric locomotive function scale Muscle thickness (MTH) at eight sites—anterior and posterior thigh (AT and PT, respectively), anterior and posterior lower leg (AL and PL, respectively), rectus abdominis (RA), anterior and posterior upper arm (AU and PU, respectively), and anterior forearm (AF)—was evaluated using B-mode ultrasound. Furthermore, the 30-s chair stand test (CS-30), 10-m walking time, zig-zag walking time, and sit-up test were assessed as physical functions. There were no significant differences in age and body mass index between the LS and non-LS groups. The percentage of skeletal muscle was lower in the LS group than in the non-LS group. Although there were no differences in the MTH of AU, PU, AF, PT, Al and PL, site-specific muscle loss was observed at RA and AT in the LS group. CS-30, 10-m walking time, zig-zag walking time, and sit-up test in the LS group were all worse than those in the non-LS group. The MTHs of RA and AT were both correlated to those physical functions. In conclusion, the LS group had site-specific muscle loss and worse physical functions. This study suggests that site-specific changes may be associated with age-related physical functions. These results may suggest what the essential characteristics of LS are.
... With regard to potential limitations, it was assumed that elite racewalkers would be symmetrical as their well-trained gait has been found to show low asymmetry for the most important kinematic variables across racewalking speeds (Tucker and Hanley, 2020). All EMG data in the present study were collected for the right side only, in line with other studies that have measured muscle activity of the right lower limb in elite racewalkers and normal walking and running (Saunders et al., 2005). An alternative approach might have been to pool left and right side data together. ...
Article
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The aim of this study was to analyze the link between the upper and lower body during racewalking. Fifteen male and 16 female racewalkers were recorded in a laboratory as they racewalked at speeds equivalent to their 20-km personal records [men: 1:23:12 (±2:45); women: 1:34:18 (±5:15)]; a single representative trial was chosen from each athlete for analysis and averaged data analyzed. Spatial variables (e.g., stride length) were normalized to stature and referred to as ratios. None of the peak upper body joint angles were associated with speed (p < 0.05) and there were no correlations between pelvic motion and speed, but a medium relationship was observed between peak pelvic external rotation (right pelvis rotated backwards) and stride length ratio (r = 0.37). Greater peak shoulder extension was associated with lower stride frequencies (r = −0.47) and longer swing times (r = 0.41), whereas peak elbow flexion had medium associations with flight time (r = −0.44). Latissimus dorsi was the most active muscle at toe-off during peak shoulder flexion; by contrast, pectoralis major increased in activity just before initial contact, concurrent with peak shoulder extension. Consistent but relatively low rectus abdominis and external oblique activation was present throughout the stride, but increased in preparation for initial contact during late swing. The movements of the pelvic girdle were important for optimizing spatiotemporal variables, showing that this exaggerated movement allows for greater stride lengths. Racewalkers should note however that a larger range of shoulder swing movements was found to be associated with lower stride frequency, and smaller elbow angles with increased flight time, which could be indicative of faster walking but can also lead to visible loss of contact. Coaches should remember that racewalking is an endurance event and development of resistance to fatigue might be more important than strength development.
... Spine stabilisation becomes necessary because of the pelvis' movement in all three cardinal planes during running. 15 For example, the pelvis is rotated in the transverse plane in order to lengthen the runner's stride. As a consequence of this pelvic rotation and to enable the runner to face forward, the trunk has to counter rotate with every step. ...
Article
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Objective The transversus abdominis muscle (TrA) is active during running as a secondary respiratory muscle and acts, together with the multifidus, as trunk stabiliser. The purpose of this study was to determine size and symmetry of TrA and multifidus muscles at rest and with contraction in endurance runners without low back pain. Design Cross-sectional study. Setting A medical imaging centre in Melbourne, Australia. Participants Thirty middle-aged (43years±7) endurance-trained male (n=18) and female (n=12) runners without current or history of low back pain. Outcome measures MRI at rest and with the core engaged. The TrA and multifidus muscles were measured for thickness and length (TrA) and anteroposterior and mediolateral thickness (multifidus). Muscle activation was extrapolated from rest to contraction and compared with the same and contralateral side. Paired t-tests were performed to compare sides and contraction status. Results Left and right TrA and multifidus demonstrated similar parameters at rest (p>0.05). However, with contraction, the right TrA and multifidus (in mediolateral direction) were 9.2% (p=0.038) and 42% (p<0.001) thicker, respectively, than their counterparts on the left. There was no TrA thickness side difference with contraction in left-handed participants (p=0.985). When stratified by sex, the contracted TrA on the right side remained 8.4% thicker, but it was no longer statistically significant (p=0.134). The side difference with contraction of the TrA became less with increasing training age. Conclusions Right-handed long-term runners without low back pain exhibit a greater right side core muscle activation when performing an isometric contraction. This activation preference diminishes with increasing training age.
... During gait, the coordination between the pelvis and lumbar segments is more rigid and less variable in the transverse plane than that in the healthy controls (Lamoth et al., 2006). Certain studies investigated the lumbar kinematics in healthy runners (Preece et al., 2016b, c;Saunders et al., 2005); however, the coordination between the lumbar spine and other segments has not been studied. ...
Article
This study aimed to analyze the coordination and variability between the thorax, lumbar, and pelvis segments in runners with chronic low back pain group (LBPG) and matched control group (CG). Twenty-six recreational runners were evaluated on a treadmill at 3.3 m/s. The coordination of the pelvis–lumbar and lumbar–thorax in all three planes and between the transverse and frontal plane of the lumbar segment were evaluated using the vector coding technique. Coordination was analyzed via histograms with the percentage of each pattern and the coupling angle during the cycle. The variability coordination was calculated from the angular deviation between the cycles. Differences were observed in the coordination patterns and in the coupling angle during the cycle. Between the pelvis–lumbar in the frontal plane, the LBPG ((x ) ̅= 50.6 % (SD = 10.7)) presented more in-phase pattern than the CG (38.6 % (8.7; P = 0.05). For the lumbar–thorax, differences occurred in all planes. Between the frontal–transverse plane of the lumbar segment, the LBPG (27.6 % (7.9)) presented more in-phase pattern than the CG (38.6 % (8.7); P = 0.02). The variability did not demonstrate the differences between the groups; these differences were observed in coordination between the lumbar and adjacent segments in all planes. The model of rigid segments and the coordination analyses were sensitive to detect these differences, and the presence of more in-phase patterns could be related to the protection mechanism in order to avoid painful movements.
... They act as spinal stabilizers for the peak lumbopelvic rotational torques at foot strikes as the ground reaction force is established. 25 DWR involves no foot strike, which may explain why higher mean %MVC values for the LM and ES were observed on the treadmill than in HK-DWR. However, the LM and ES activation during CC-DWR and LW remained comparable. ...
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OBJECTIVE: To investigate the efficacy of a 4-week community aquatic physiotherapy program with Ai Chi or the Bad Ragaz Ring Method (BRRM) on pain and disability in adults with chronic low back pain (CLBP). METHODS: Adults with CLBP (n = 44; mean ± SD age, 52.6 ± 5.5 y; 37 women) were assigned to either an Ai Chi (n = 23) or BRRM (n = 21) program (4 weeks, twice weekly). RESULTS: Both the Ai Chi (−1.4; 95% CI −2.6 to −0.2; p = .025) and BRRM (−2.0, 95% CI −3.1 to −0.8; p = 0.003) groups demonstrated significant pre- to post-treatment decreases in Roland-Morris Disability Questionnaire scores and improvements in prone bridge duration (Ai Chi: 11.7 s; 95% CI 1.6 to 21.8; p = 0.025; BRRM: 19.0 s; 95% CI 6.1 to 31.8; p = 0.006). The Ai Chi group revealed a significant improvement in single-leg stand test duration (2.9 s; 95% CI 0.1 to 5.7; p = 0.045) and the BRRM group reported significant decrease in pain intensity (−11.6; 95% CI −19.1 to −4.2; p = 0.004). CONCLUSIONS: A 4-week aquatic physiotherapy program with Ai Chi or BRRM resulted in significant pre- to post-treatment improvements in disability and global core muscle endurance. Ai Chi appeared to have an additional benefit of improving single- leg standing balance and BRRM an additional benefit of reducing pain.
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Background The biomechanics of the trunk and lower limbs during walking and running gait are frequently assessed in individuals with low back pain (LBP). Despite substantial research, it is still unclear whether consistent and generalizable changes in walking or running gait occur in association with LBP. The purpose of this systematic review was to identify whether there are differences in biomechanics during walking and running gait in individuals with acute and persistent LBP compared with back-healthy controls. Methods A search was conducted in PubMed, CINAHL, SPORTDiscus, and PsycINFO in June 2019 and was repeated in December 2020. Studies were included if they reported biomechanical characteristics of individuals with and without LBP during steady-state or perturbed walking and running. Biomechanical data included spatiotemporal, kinematic, kinetic, and electromyography variables. The reporting quality and potential for bias of each study was assessed. Data were pooled where possible to compare the standardized mean differences (SMD) between back pain and back-healthy control groups. Results Ninety-seven studies were included and reviewed. Two studies investigated acute pain and the rest investigated persistent pain. Nine studies investigated running gait. Of the studies, 20% had high reporting quality/low risk of bias. In comparison with back-healthy controls, individuals with persistent LBP walked slower (SMD = -0.59; 95% confidence interval (95%CI): -0.77 to -0.42)) and with shorter stride length (SMD = -0.38; 95%CI: -0.60 to -0.16). There were no differences in the amplitude of motion in the thoracic or lumbar spine, pelvis, or hips in individuals with LBP. During walking, coordination of motion between the thorax and the lumbar spine/pelvis was significantly more in-phase in the persistent LBP groups (SMD = -0.60; 95%CI:-0.90 to -0-.30), and individuals with persistent LBP exhibited greater amplitude of activation in the paraspinal muscles (SMD = 0.52; 95%CI: 0.23 to 0.80). There were no consistent differences in running biomechanics between groups. Conclusion There is moderate to strong evidence that individuals with persistent LBP demonstrate differences in walking gait compared to back-healthy controls.
Pregnancy and childbirth are associated with increased inter-recti distance (IRD)/diastasis recti abdominis (DRA), pelvic joint laxity, and decreased physical activity levels. Recreational running is an accessible, popular form of exercise that may challenge pelvic stability in postpartum women. To assess the impact of an 8-week abdominal muscle retraining program on IRD and pelvic running mechanics in women up to 2 years postpartum. Pre/posttest single-arm intervention study. Thirteen postpartum women (32.8 ± 2.7 years of age; 1-3 pregnancies; 7 weeks to 2 years postpartum) who were recreational runners participated. Ultrasound imaging measured IRD above and below the umbilicus. Thickness of the internal oblique (IO) and transversus abdominis (TrA) muscles was assessed with ultrasonography at rest and during performance of an abdominal draw-in maneuver. Participants underwent an 8-week abdominal muscle retraining program utilizing ultrasonography as biofeedback. Running gait was assessed with 3-dimensional motion capture at study enrollment (baseline), end of the intervention, and 6-week follow-up. Inter-recti distance below the umbilicus decreased from baseline to end of intervention (P = .013) and remained stable at follow-up (P = .459). Inter-recti distance above the umbilicus, IO and TrA activation ratio, and running mechanics did not change (P > .05). Women reported increased running speed following the intervention (P = .021). An 8-week abdominal muscle retraining program reduced IRD below the umbilicus in recreational runners up to 2 years postpartum, suggesting therapeutic exercise may be part of conservative management for DRA.
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Background Gait and balance characteristics often appear altered in older adults with Alzheimer's disease (AD). However, no studies have examined the effects of pelvic tilt exercise on improvement in gait disturbances and pelvic tilt in older adults with AD. This study investigated the effect of pelvic tilt exercise using pressure-based visual biofeedback training (PVFT) on the gait and balance of older adults with AD. Methods A total of 15 older adults with AD participated in the study. Subjects performed the pelvic tilt exercise using PVFT during the 4-week intervention that we had developed for training. At baseline and after the 4-week intervention, gait analysis was measured using the GAITRite system, and the pelvic tilt range was measured using a palpation meter (PALM). The Berg balance scale (BBS) was assessed at baseline and after the 4-week intervention program. The mean values of the gait parameters, the pelvic tilt range at baseline and after the 4-week intervention conditions were analyzed by paired t-test. Results Significant differences (P < 0.05) of mean values were found in the gait speed, stride length (left and right), pelvic tilt range and BBS scores after the 4-week intervention compared with baseline. Conclusions Overall, the pelvic tilt exercise using PVFT improved gait speed, stride length, and pelvic tilt range after the intervention. These findings suggest that the pelvic tilt exercise with PVFT can be an effective training method with specific and simple techniques for improving gait disturbances in older adults with AD.
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Background: Rehabilitation approaches should be based on an understanding of the mechanisms underpinning functional recovery. Yet, the mediators that drive an improvement in post-surgical pain-related disability in individuals with cervical radiculopathy (CR) is unknown. The aim of the present study is to use Bayesian Networks (BN) to learn the probabilistic relationships between physical and psychological factors, and pain-related disability in CR. Methods: We analysed a prospective cohort dataset of 201 post-surgical individuals with CR. Fifteen variables were used to build a BN model: age, sex, neck muscle endurance, neck range of motion, neck proprioception, hand grip strength, self-efficacy, catastrophizing, depression, somatic perception, arm pain intensity, neck pain intensity, and disability. Results: A one point increase in a change of self-efficacy at six months was associated with a 0.09 point decrease in a change in disability at 12 months (t = -64.09, P < 0.001). Two pathways led to a change in disability: a direct path leading from a change in self-efficacy at six months to disability, and an indirect path which was mediated by neck and arm pain intensity changes at six and 12 months. Conclusions: This is the first study to apply BN modelling to understand the mechanisms of recovery in post-surgical individuals with CR. Improvements in pain-related disability was directly and indirectly driven by changes in self-efficacy levels. The present study provides potentially modifiable mediators that could be the target of future intervention trials. BN models could increase the precision of treatment and outcome assessment of individuals with CR.
Article
Belly dance was used to investigate control of rhythmic undulating trunk movements in humans. Activation patterns in lumbar erector spinae muscles were recorded using surface electromyography at four segmental levels spanning T10 to L4. Muscle activation patterns for movement tempos of 2 Hz, 3 Hz and as fast as possible (up to 6 Hz) were compared to test the hypothesis that frequency modulates muscle timing, causing pattern changes analogous to gait transitions. Groups of trained and untrained female subjects were compared to test the hypothesis that experience modifies muscle coordination patterns and the capacity for selective motion of spinal segments. Three distinct coordination patterns were observed. An ipsilateral simultaneous pattern (S) and a diagonal synergy (D) dominated at lower frequencies. The S pattern was selected most often by novices and resembled the standing wave of activation underlying the alternating lateral trunk bending in salamander trotting. At 2 Hz, most trained subjects selected the D pattern, suggesting a greater capacity for segmental specificity compared to untrained. At 3-4 Hz, there emerged an asynchronous (A) pattern analogous to the rostral-caudal traveling wave in salamander and lamprey swimming. The neural networks and mechanisms identified in primitive vertebrates, such as chains of coupled oscillators and segmental crossed inhibitory connections, could explain the patterns observed here in humans. Training allows modification of these patterns, possibly through improved capacity for selectively exciting or inhibiting segmental pattern generators.
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Trunk flexion is an understudied biomechanical variable that potentially influences running performance and susceptibility to injury. We present and test a theoretical model relating trunk flexion angle to stride parameters, joint moments and ground reaction forces that have been implicated in repetitive stress injuries. Twenty-three participants (12 male, 11 female) ran at preferred trunk flexion and three more flexed trunk positions (moderate, intermediate and high) on a custom built Bertec™ instrumented treadmill while kinematic and kinetic data were simultaneously captured. Markers adhered to bony landmarks tracked the movement of the trunk and lower limb. Stride parameters, moments of force and ground reaction force were calculated using Visual 3D (C-Motion ©) software. From preferred to high trunk flexion, stride length decreased 6% (P < 0.001) and stride frequency increased 7% (P < 0.001). Extensor moments at the hip increased 70% (P < 0.001), but knee extensor (P < 0.001) and ankle plantarflexor moments (P < 0.001) decreased 22% and 14%, respectively. Greater trunk flexion increased rate of loading by 29% (P < 0.01) and vertical ground reaction force impact transients by 20% (P < 0.01). Trunk flexion angle during running has significant effects on stride kinematics, lower extremity joint moments and ground reaction force and should be further investigated in relation to running performance and repetitive stress injuries.
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Modeling the lumbar spine as a single rigid segment does not consider the relative contribution of regional or segmental motion that may occur during a task. The current study used a multi-segment model to measure three-dimensional (3D) upper and lower lumbar spine motion during walking and prone hip extension (PHE). The degree of segmental redundancy during these movements was assessed by calculating the cross-correlation of the segmental angle time series (R0) and the correlation of the segmental ranges of motion (RROM). All correlation coefficients (R0, RROM) were interpreted as follows: very strong (0.80-1.00), strong (0.60-0.79), moderate (0.40-0.59), weak (0.20-0.39), and very weak (0.00-0.19). Strong/very strong positive R0 were demonstrated between the two segments in all three planes during PHE and in the transverse plane during walking. Weak/moderate R0 were demonstrated in the sagittal and frontal planes during walking. Strong/very strong positive RROM were demonstrated in the transverse plane during PHE, and moderate positive RROM was demonstrated in the sagittal plane during walking. Non-significant RROM were demonstrated for all other planes and movements. These results suggest the motion patterns of the upper and lower lumbar regions during walking and PHE are sufficiently distinct to warrant the use a multi-segment model for these movements. It also appears that the degree of redundancy between the upper and lower lumbar regions may be task-dependent.
Article
The effects of restricting dorso-lumbar spine mobility on electromyographic activity of the erector spinae, quadriceps femoris, hamstrings and gastrocnemius muscles in runners was investigated. Thermoplastic casting material was fashioned into a rigid orthosis and used to restrict spinal motion during running. Volunteers ran on a treadmill at 2.78 m/sec, under normal conditions and with spinal motion restricted. Surface electromyographic data was collected during both sets of trials. Normal electromyographic data was also compared with previous authors to determine similarity with their electromyographic data. Results Casted running resulted in an increase in erector spinae (p < 0.01) and quadriceps femoris (p = 0.02) electromyography activity. Total stride time and swing time of gait were decreased during casted running (p < 0.01), indicating a shift towards shorter and thus more frequent steps to run the same distance. The normal electromyographic data collected was in agreement with previously reported work. Conclusions Neurological control over muscle and the fascia surrounding it is responsible for joint movement and load transfer. Experimentally restricting spinal motion during running demonstrated an increase in erector spinae and rectus femoris electromyographic activity. This lends support to the hypothesis that decreased spinal mobility may be a contributing factor to overuse muscle injuries in runners.
Article
Maintaining stability under dynamic conditions is an inherent challenge to bipedal running. This challenge may impose an energetic cost (Ec) thus hampering endurance running performance, yet the underlying mechanisms are not clear. Wireless tri-axial trunk accelerometry is a simple tool that could be used to unobtrusively evaluate these mechanisms. Here, we test a cost of instability hypothesis by examining the contribution of trunk accelerometry-based measures (tri-axial root mean square, step and stride regularity, and sample entropy) to inter-individual variance in Ec (kcal.km-1) during treadmill running. Accelerometry and indirect calorimetry data were collected concurrently from 30 recreational runners (16 men; 14 women) running at their highest steady-state running speed (80.65 ± 5.99% VO2 max). After reducing dimensionality with factor analysis, the effect of dynamic stability features on Ec was evaluated using hierarchical multiple regression analysis. Three accelerometry-based measures could explain an additional 10.4% of inter-individual variance in Ec after controlling for body mass, attributed to anteroposterior stride regularity (5.2%), anteroposterior RMS ratio (3.2%), and mediolateral sample entropy (2.0%). Our results lend support to a cost of instability hypothesis, with trunk acceleration waveform signals that are 1) more consistent between strides anteroposterioly, 2) larger in amplitude variability anteroposterioly, and 3) more complex mediolaterally, are energetically advantageous to endurance running performance. This study shows that wearable trunk accelerometry is a useful tool for understanding the Ec of running, and that running stability is important for economy in recreational runners.
Article
Aims and background: The aim of this study was evaluation the kinematics of the hip, knee, ankle and pelvis in low back pain patients who had pronated foot before and after a selected training protocol during walking. Material and methods: 23 men (15 men with low back pain and pronated foot as a control group and 17 men with low back pain and pronated foot as experimental group) were volunteered to participate in this study. The experimental group didresistance training with Teraband for 12 weeks, 3 sessions per week. The kinematic data was recorded by 4 Vicon cameras during walking. Findings: The results of this study in the experimental group showed that during the post-test, the walking speed was higher than the pre-test (p<0.05). The results showed that the effect of time factor on pelvic posterior tilt was significant (p=0.001). Also, increas in ankle planar flexion (about 6 degrees) and the ankle joint range of motion (about 4 degree) during the post-test in comparison with the pre-test in the experimental group were observed (p=0.000). Conclusion: Regarding the increase in walking speed in low back pain patients with pronated foot during post-test compared to the pre-test, the less of changes in the lower limb joints angles and the absence of absolute pelvic angle indicate better mechanical efficiency of walking after exercise program.
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Background: The mechanisms of action that facilitate improved outcomes after conservative rehabilitation are unclear in individuals with cervical radiculopathy (CR). This study aims to determine the pathways of recovery of disability with different exercise programs in individuals with CR. Methods: We analysed a dataset of 144 individuals with CR undergoing conservative rehabilitation. Eleven variables collected at baseline, 3, 6, and 12 months follow-up were used to build a Bayesian Network (BN) model: treatment group (neck-specific versus general exercises), age, sex, self-efficacy, catastrophizing, kinesiophobia, anxiety, neck-arm pain intensity, headache pain intensity, and disability. The model was used to quantify the contribution of different mediating pathways on the outcome of disability at 12th months. Results: All modelled variables were conditionally independent from treatment groups. A one-point increase in anxiety at 3rd month was associated with a 2.45 point increase in 12th month disability (P<0.001). A one-point increase in head pain at 3rd month was associated with a 0.08 point increase in 12th month disability (P<0.001). Approximately 83% of the effect of anxiety on disability was attributable to self-efficacy. Approximately 88% of the effect of head pain on disability was attributable to neck-arm pain. Conclusions: No psychological or pain related variables mediated the different treatment programs with respect to the outcome of disability. Thus, the specific characteristics investigated in this study did not explain the differences in mechanisms of effect between neck-specific training and prescribed physical activity. The present study provides candidate modifiable mediators that could be the target of future intervention trials.
Article
Background: Inertial Measurement Unit (IMU)-based gait analysis algorithms have previously been validated in healthy controls. However, little is known about the efficacy, performance, and applicability of these algorithms in clinical populations with gait deviations such as lower limb prosthesis users (LLPUs). Research question: To compare the performance of 3 different IMU-based algorithms to demarcate steps from LLPUs. Methods: We used a single IMU sensor affixed to the midline lumbopelvic region of 17 transtibial (TTA), 16 transfemoral (TFA) LLPUs, and 14 healthy controls (HC). We collected acceleration and angular velocity data during overground walking trials. Step demarcation was evaluated based on fore-aft acceleration, detecting either: (i) maximum acceleration peak, (ii) zero-crossing, or (iii) the peak immediately preceding a zero-crossing. We quantified and compared the variability (standard deviation) in acceleration waveforms from superposed step intervals, and variability in step duration, by each algorithm. Results: We found that the zero-crossing algorithm outperformed both peak detection algorithms in 65% of TTAs, 81% of TFAs, and 71% of HCs, as evidenced by lower standard deviations in acceleration, more consistent qualitative demarcation of steps, and more normally distributed step durations. Significance: The choice of feature-based algorithm with which to partition IMU waveforms into individual steps can affect the quality and interpretation of estimated gait spatiotemporal metrics in LLPUs. We conclude that the fore-aft acceleration zero-crossing serves as a more reliable feature for demarcating steps in the gait patterns of LLPUs.
Thesis
La scoliose idiopathique est la déformation du rachis la plus fréquente. Bien que le diagnostic soit clinique, le suivi et les prises de décisions thérapeutiques (traitement orthopédique et/ou chirurgical), reposent sur des critères d’évaluation radiographiques structurels. La littérature a montré qu’il existait dans la scoliose idiopathique des modifications de l’orientation de la tête, du tronc et du bassin dans les 3 plans de l’espace, associés à des troubles du contrôle postural, compromettant ainsi la stabilité en statique. Il existe également une modification de la position du centre de masse lié à la déformation, pouvant donc affecter la stabilité dynamique au cours de la marche. La problématique de ce travail était de caractériser les compensations posturales et fonctionnelles par approches biomécaniques des scolioses idiopathiques de l’adolescent (SIA), en vue d’améliorer la prise en charge clinique et plus particulièrement les stratégies chirurgicales.Dans notre 1ère étude, une modification significative de l’équilibre de la marche, mesuré par la marge de stabilité dynamique, était mise en évidence dans les déformations rachidiennes. Dans notre 2ème étude, appliquée uniquement à la SIA sévère avec indication de chirurgie, aucune modification de leur équilibre dynamique n’a été mise en évidence, témoin du caractère performant de la marche de ces patients. Dans la 3ème étude, l’approche analytique en baropodométrie dynamique et statique a mis en évidence des stratégies d’équilibrations spatiales, croisées et bilatérales, dans le but de symétriser les paramètres fonctionnels de la marche. Ces stratégies étaient liées à la localisation de la déformation et aux déséquilibres structuraux dans le plan frontal. Les déformations dans le plan sagittal avaient surtout un impact dans la modulation de l’amorti et de la propulsion au cours de la marche avec une influence particulière de la position du bassin.
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Normalization of electromyographic (EMG) data has been described in the scientific literature as crucial for comparisons between subjects and between muscles. The reference value used in the normalization equation has, however, varied across reports. Comparison between studies could be facilitated by use of a common value. We propose the best way to select the common value is through a reliability approach. Accordingly, the purpose of this study was to identify which of three EMG normalization values provided the most reproducible data set. The gastrocnemius EMG results from 20 normal persons and 20 individuals with anterior cruciate deficiency who were participating in a larger study were normalized to a maximum voluntary isometric contraction (MVIC) EMG, peak dynamic EMG, and mean dynamic EMG. Values were then subjected to evaluation using four statistical measures: inter and intrasubject coefficients of variation (CV), variance ratio (VR), and intraclass correlation coefficient (ICC). The CV measures, while not being reflective of reliability were included for comprehensive consideration in view of other literature. The intersubject CV which measures group variability and the intrasubject CV which measures precision were lower for the dynamic conditions, however, the VR and ICC suggested reproducibility was best with EMG from the MVIC. Given that other studies have advocated normalizing EMG by taking data from the dynamic event, reconsideration may be warranted if high reproducibility is desired. Interpretations of the findings given the population, muscle and condition studied are discussed.
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Electromyography (EMG) and normalized EMG have been accepted as methods of quantifying the activity level of a muscle. Normalized EMG, in conjunction with the EMG/force relationship and muscle cross-sectional area data, allows researchers to estimate the amount of muscle force exerted across a joint. An accurate description of this muscle force is a critical input to models designed to describe the risk of injury of a task. In order to be able to make statements about the relative intensity of an EMG signal, researchers who use normalization procedures take a given EMG activity level, at a known joint angle, and relate it to some reference activity level obtained at that particular joint angle. However, there have been studies where the EMG activity of an unrestricted dynamic task, such as walking, cycling, performing an occupational task, etc., has been normalized with respect to an EMG value taken during a single maximum voluntary contraction performed at one reference joint angle. This practice will render inaccurate results because at different joint angles there are changes in the portion of the muscle within the viewing area of the electrode, as well as changes in the length/tension relationship of the muscle which would cause changes in the maximum EMG value. The present study was an attempt to quantify the errors associated with normalization relative to a reference EMG value collected at an arbitrary joint position. Four subjects performed a series of controlled trunk extension exertions. As they performed these exertions the EMG activities were collected for eight trunk muscles. The task EMG values that resulted were then: (1) all normalized with respect to the maximum EMG at a single arbitrary trunk angle and (2) each normalized with respect to that specific trunk angle's maximum EMG. The results show that for the primary trunk extensors (erector spinae) large errors (greater than 75%) resulted from normalization using a single reference point and the magnitude of these errors followed consistent patterns within subjects as a function of trunk angle.
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Locomotion was first achieved by the motion of the spine. The limbs came after, as an improvement, not as a substitute; and yet, analysis of bipedal gait concentrates almost exclusively on the motion of the limbs. The requirements for land locomotion are examined from a general point of view and the evolution of the vertebrate spine is presented as a mechanism designed to move the animal. The necessary spinal movements are also analysed; the role of the musculoskeletal system is discussed and it is shown that the lumbar spine is a key structure in land locomotion, the pelvis being driven by the spine. The optimum control of motion demands that the stress at all the intervertebral joints should be minimized and equalized. This theory of locomotion requires the central nervous system to control the torque at those intervertebral joints and suggests that a breakdown of the control system would result in torsional failure of the spine. The theory is supported by EMG, force and torque data collected from several sources.
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The experimental study of joint kinematics in three dimensions requires the description and measurement of six motion components. An important aspect of any method of description is the ease with which it is communicated to those who use the data. This paper presents a joint coordinate system that provides a simple geometric description of the three-dimensional rotational and translational motion between two rigid bodies. The coordinate system is applied to the knee and related to the commonly used clinical terms for knee joint motion. A convenient characteristic of the coordinate system shared by spatial linkages is that large joint displacements are independent of the order in which the component translations and rotations occur.
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Transverse pelvis and thorax rotations were studied during walking in 39 patients with nonspecific low back pain and 19 healthy participants. To gain insight into the consequences of low back pain for gait and to identify clinically useful measures for characterizing the quality of walking in patients with low back pain. Gait studies in patients with low back pain have reported a decrease in walking velocity. In normal gait, in-phase pelvis-thorax coordination (synchronicity) evolves toward antiphase coordination (counterrotation) as walking velocity increases. This study examined the effect of walking velocity on pelvis and thorax rotations in patients with low back pain. Amplitudes of pelvis and thorax rotations were calculated, and spectral analyses were performed. Pelvis-thorax coordination was characterized in terms of relative Fourier phase, and coupling strength was assessed by means of cross-spectral analysis. In comparison with healthy participants, relative Fourier phase was significantly smaller in low back pain patients for walking velocities of 3.8 km/h and higher, whereas coupling strength was significantly higher for velocities from 1.4 to 3.0 km/h. No significant group differences were found in amplitude or spectral content of individual pelvis and thorax rotations. In comparison with healthy participants, the gait of patients with low back pain was characterized by a more rigid, less flexible pelvis-thorax coordination in the absence of significant differences in the kinematics of the component rotations. This result suggests that coordination measures are more adequate in assessing quality of walking in patients with low back pain than are kinematic measures pertaining to the individual segment rotations, and that conservative therapy should use methods aimed at improving intersegmental coordination.
Article
Study Design: The contribution of transversus abdominis to spinal stabilization was evaluated indirectly in people with and without low back pain using an experimental model identifying the coordination of trunk muscles in response to a disturbance to the spine produced by arm movement. Objectives: To evaluate the temporal sequence of trunk muscle activity associated with arm movement, and to determine if dysfunction of this parameter was present in patients with low back pain. Summary of Background Data: Few studies have evaluated the motor control of trunk muscles or the potential for dysfunction of this system in patients with low back pain. Evaluation of the response of trunk muscles to limb movement provides a suitable model to evaluate this system. Recent evidence indicates that this evaluation should include transversus abdominis. Methods: While standing, 15 patients with low back pain and 15 matched control subjects performed rapid shoulder flexion, abduction, and extension in response to a visual stimulus. Electromyographic activity of the abdominal muscles, lumbar multifidus, and the contralateral deltoid was evaluated using fine‐wire and surface electrodes. Results: Movement in each direction resulted in contraction of trunk muscles before or shortly after the deltoid in control subjects. The transversus abdominis was invariably the first muscle active and was not influenced by movement direction, supporting the hypothesized role of this muscle in spinal stiffness generation. Contraction of transversus abdominis was significantly delayed in patients with low back pain with all movements. Isolated differences were noted in the other muscles. Conclusions: The delayed onset of contraction of transversus abdominis indicates a deficit of motor control and is hypothesized to result in inefficient muscular stabilization of the spine.
Article
The DLT method was implemented on a SELSPOT-HP1000 system to study the 3d kinematics of the pelvis/thorax during locomotion. An important feature of our DLT implementation is an interactive calibration procedure which is flexible, accurate and fast. Extensive testing was used to validate the system both dynamically and statically.
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The purpose of this study was to examine the three-dimensional low back loads, spinal motions, and trunk muscular activity during gait. Specific objectives involved assessment of the effects of walking speed, and arm swing on spinal loads, lumbar spine motion, and muscular activation. An in vivo modeling experiment using five male participants. Thirty walking trials were performed by each participant yielding five repeats of each condition (3 walking cadences x 2 arm swing conditions). Walking is often prescribed as a rehabilitation task for individuals with low back injuries. However, there are few studies which have examined the joint loading, spinal motions, and muscular activity present when walking. Additionally, the majority of studies examining spine loading during gait have used an inverse dynamics model, commencing at the cranial aspect of the body, approach which does not include the impulsive phases of gait (i.e. heel strikes and toe offs). Low back joint forces (bone on bone) and moments were determined using an anatomically complex three-dimensional model (detailing 54 muscles and the passive structures acting at the low back) during three walking cadences and with free arm swing or restricted arm swing. In order to assess the influence of the transient factors such as heel contact on the joint forces a bottom up (from the feet to the lumbar spine) rigid link segment analyses approach was used as one input to the three-dimensional anatomic model. Lumbar spine motion and trunk muscle activation levels were also recorded to assist in partitioning forces amongst the active and passive tissues of the low back. Net joint anterior-posterior shear loading was the only variable significantly affected by walking cadence (fast versus slow P < 0.0003). No variable was significantly affected by the arm swing condition. Trends demonstrated an increase in all variables with increased walking cadence. Similarly, most variables, with the exception of axial twist and lateral bend lumbar spine motion and lateral joint shear, demonstrated increasing trends caused by the restriction of normal arm swing. Tissue loading during walking appears to be below levels caused by many specific rehabilitation tasks, suggesting that walking is a wise choice for general back exercise and rehabilitation programs. Slow walking with restricted arm swing produced more 'static' lumbar spine loading and motion patterns, which could be detrimental for certain injuries and tissues. Fast walking produced a more cyclic loading pattern.
Article
We present the results of a study in which we investigated the patterns and ranges of movement of the lower thoracic and lumbar spinal segments and the pelvis in subjects walking at two self-selected speeds. Our subjects were aged from 20 to 82 years and both genders were equally represented. Measurements were carried out using a video-based system. We detected increased range of motion in each segment with increased walking speed, few gender-related differences in patterns or ranges of motion and significant reduction in spinal range of motion with advancing age. Our findings suggest, however, that these age-related changes are more likely to be step-length dependent than an intrinsic feature of aging.
Article
Evaluation of trunk movements, trunk muscle activation, intra-abdominal pressure and displacement of centres of pressure and mass was undertaken to determine whether trunk orientation is a controlled variable prior to and during rapid bilateral movement of the upper limbs. Standing subjects performed rapid bilateral symmetrical upper limb movements in three directions (flexion, abduction and extension). The results indicated a small (0.4-3.3 degrees) but consistent initial angular displacement between the segments of the trunk in a direction opposite to that produced by the reactive moments resulting from limb movement. Phasic activation of superficial trunk muscles was consistent with this pattern of preparatory motion and with the direction of motion of the centre of mass. In contrast, activation of the deep abdominal muscles was independent of the direction of limb motion, suggesting a non-direction specific contribution to spinal stability. The results support the opinion that feedforward postural responses result in trunk movements, and that orientation of the trunk and centre of mass are both controlled variables in relation to rapid limb movements.
Article
We used a high-resolution ultrasound to make electrical recordings from the transversus abdominis muscle in humans. The behavior of this muscle was then compared with that of the external oblique and rectus abdominis in six normal subjects in the seated posture. During voluntary efforts such as expiration from functional residual capacity, speaking, expulsive maneuvers, and isovolume "belly-in" maneuvers, the transversus in general contracted together with the external oblique and the rectus abdominis. In contrast, during hyperoxic hypercapnia, all subjects had phasic expiratory activity in the transversus at ventilations between 10 and 18 l/min, well before activity could be recorded from either the external oblique or the rectus abdominis. Similarly, inspiratory elastic loading evoked transversus expiratory activity in all subjects but external oblique activity in only one subject and rectus abdominis activity in only two subjects. We thus conclude that in humans 1) the transversus abdominis is recruited preferentially to the superficial muscle layer of the abdominal wall during breathing and 2) the threshold for abdominal muscle recruitment during expiration is substantially lower than conventionally thought.
Article
Anatomical landmarks on the body surface can be measured with high accuracy by using rasterstereography and surface curvature analysis. The present study shows that the lumbar dimples can be localized with a statistical error of about 1 mm. It is generally assumed that the dimples are in close relation to the pelvis (in particular to the PSISs) and may thus be taken as indicators for pelvis movements. By introducing an artificial pelvis tilt of up to +/- 10 degrees this relation was examined. In fact, a nearly perfect correlation (r approximately equal to 0.99) between landmark and pelvis movements was observed. Asymmetries of pelvis motion due to scoliotic deformity were not observed. There was, however, a systematic lag of the dimple movements, resulting in a displacement of the dimples of up to +/- 1.5 mm relative to the pelvis (for +/- 10 degrees pelvis tilt). Either a soft tissue effect or a torsion of the pelvis may be responsible for this behaviour. The theory of pelvis torsion is confirmed by the fact that the orientation of the back surface at the locus of the dimples reveals a corresponding torsion of similar magnitude and sign. A torsion angle of about +/- 1.5 degrees in either sacro-iliac joint is sufficient to explain the observed dimple lag and the surface torsion. An independent measurement (e.g. using roentgenphotogrammetry) would be desirable to further validate this theory. According to our measurements the dimples of the PSISs cannot be taken as exact indicators for orientation and movement of the pelvis.(ABSTRACT TRUNCATED AT 250 WORDS)
Article
A technique for the measurement of rotational human back movements in three dimensions has been developed. The spatial coordinates of reflective markers on rigs attached to the back surface were calculated using a calibrated television/computer system. A mathematical analysis of the change in these coordinates, as subjects performed set manoeuvres, was developed to provide unique descriptions of the rotational movements in terms of clinical angles related to anatomical frames of reference. The technique produced angles of rotation with maximum errors about any axis of +/- 2 degrees, with a root mean square error of less than 1 degree. The analysis of back movements using surface markers was shown to be feasible from studies of six volunteers who demonstrated consistent patterns of movement which were similar to previously reported patterns of spinal movement measured radiographically.
Article
An electromyographic study of the lower extremity muscles was undertaken in order to compare jogging, running, and sprinting. The study demonstrated that as the speed of gait increased, the support phase decreased, from 620 msec for walking to 260 msec for jogging to 220 msec for running to 140 msec for sprinting. The electromyographic data demonstrated that all muscle groups except the hip flexor and adductor longus were active during foot descent, floor contact, and midsupport. There was absence of muscle function during the late toe-off phase except that demonstrated by the adductor longus and the abdominal muscles during sprinting. The main muscle group that appears to increase the speed of gait is that of the hip flexors, which is closely linked to the knee extensors in order to propel the body forward in the line of progression. There was little or no activity in the gastrocnemius or in the intrinsic muscles of the foot about the time of toe-off, leading the authors to conclude that push-off per se does not appear to occur.
Article
Trunk strengths were measured in 27 health males and 30 health females, and in 25 male and 15 female patients with low-back pain and/or sciatica. Maximum voluntary isometric strengths were measured during attempted flexion, extension, and lateral bending from an upright standing position. Both male and female patients had approximately 60% of the absolute trunk strengths of the corresponding healthy subjects. Intra-individual trunk strength ratios were used to interpret the results. Use of these ratios tends to avoid interpretational problems created by the general weakness of the patients and any lack of motivation of either patients or healthy subjects. The ratios showed that the patients had attempted extension strengths that were significantly less than their strengths in the other types of movements tested. The strength ratios for attempted extension were particularly low for patients with sciatica.
Article
The function of lumbar back muscles was studied by relating their activity patterns to trunk movements in 7 healthy adult males during normal walking (1.0-2.5 m/s) and running (2.0-7.0 m/s) on a treadmill. The movements of the trunk in the sagittal and frontal planes were recorded with a Selspot optoelectronic system using infrared light emitting diodes as markers. The electromyographic (EMG) activity from the two main portions of the lumbar erector spinae muscles (Multifidus and Longissimus) was recorded bilaterally with intramuscular wire electrodes. The angular displacements of the trunk showed regular oscillations, but their shape, magnitude and relation to the step cycle were different in the two planes (sagittal and frontal) and varied with speed and mode of progression. The EMG pattern in both muscles showed a bilateral cocontraction with two main bursts of activity per step cycle starting just before each foot was placed on the ground. Relating the EMG to the movements of the trunk indicated that the main function of the lumbar erector spinae muscles is to restrict excessive trunk movements. During walking this restricting action is most evident for movements in the frontal plane, whereas in running the lumbar back muscles mainly control the movements in the sagittal plane.
Article
Models of the abdominal musculature, which used single slice MRI or CT scans to reconstruct the anatomy, were unable to explain magnitudes of abdominal flexion moment which exceed 100 Nm in living subjects. For example, the muscle areas and corresponding flexor moment arms measured from a transverse scan at L4-L5 predict maximum moments less than 50 Nm. The architecture of rectus abdominis, external and internal obliques, and transverse abdominis was examined from cadaveric specimens, from which the geometric details were incorporated into a revised model. Scaling of the muscles to obtain physiological cross-sectional areas were obtained using two methods: serial MRI slices; and from several locations of ultrasound measurement. The two major anatomically justified improvements that had dramatic effects on flexor moment production were: the increase in flexor moment arms of muscles (approximately 30%) measured in a standing posture when compared to the supine posture for MRI examination; reinterpretation of the line of action of the obliques which transmit their flexor forces through the linea semilunaris (increasing their effective flexor moment arm) to eventual skeletal attachment at the pelvis.
Article
The contribution of transversus abdominis to spinal stabilization was evaluated indirectly in people with and without low back pain using an experimental model identifying the coordination of trunk muscles in response to a disturbances to the spine produced by arm movement. To evaluate the temporal sequence of trunk muscle activity associated with arm movement, and to determine if dysfunction of this parameter was present in patients with low back pain. Few studies have evaluated the motor control of trunk muscles or the potential for dysfunction of this system in patients with low back pain. Evaluation of the response of trunk muscles to limb movement provides a suitable model to evaluate this system. Recent evidence indicates that this evaluation should include transversus abdominis. While standing, 15 patients with low back pain and 15 matched control subjects performed rapid shoulder flexion, abduction, and extension in response to a visual stimulus. Electromyographic activity of the abdominal muscles, lumbar multifidus, and the surface electrodes. Movement in each direction resulted in contraction of trunk muscles before or shortly after the deltoid in control subjects. The transversus abdominis was invariably the first muscle active and was not influenced by movement direction, supporting the hypothesized role of this muscle in spinal stiffness generation. Contraction of transversus abdominis was significantly delayed in patients with low back pain with all movements. Isolated differences were noted in the other muscles. The delayed onset of contraction of transversus abdominis indicates a deficit of motor control and is hypothesized to result in inefficient muscular stabilization of the spine.
Little consensus exists in the literature regarding methods for determination of the onset of electromyographic (EMG) activity. The aim of this study was to compare the relative accuracy of a range of computer-based techniques with respect to EMG onset determined visually by an experienced examiner. Twenty-seven methods were compared which varied in terms of EMG processing (low pass filtering at 10, 50 and 500 Hz), threshold value (1, 2 and 3 SD beyond mean of baseline activity) and the number of samples for which the mean must exceed the defined threshold (20, 50 and 100 ms). Three hundred randomly selected trials of a postural task were evaluated using each technique. The visual determination of EMG onset was found to be highly repeatable between days. Linear regression equations were calculated for the values selected by each computer method which indicated that the onset values selected by the majority of the parameter combinations deviated significantly from the visually derived onset values. Several methods accurately selected the time of onset of EMG activity and are recommended for future use.
Article
This review article summarizes the current literature regarding the analysis of running gait. It is compared to walking and sprinting. The current state of knowledge is presented as it fits in the context of the history of analysis of movement. The characteristics of the gait cycle and its relationship to potential and kinetic energy interactions are reviewed. The timing of electromyographic activity is provided. Kinematic and kinetic data (including center of pressure measurements, raw force plate data, joint moments, and joint powers) and the impact of changes in velocity on these findings is presented. The status of shoewear literature, alterations in movement strategies, the role of biarticular muscles, and the springlike function of tendons are addressed. This type of information can provide insight into injury mechanisms and training strategies. Copyright 1998 Elsevier Science B.V.
Article
Normalization of muscle activity has been commonly used to determine the amount of force exerted by a muscle. The most widely used reference point for normalization is the maximum voluntary contraction (MVC). However, MVCs are often subjective, and potentially limited by sensation of pain in injured individuals. The objective of the current study was to develop a normalization technique that predicts an electromyographic (EMG) reference point from sub-maximal exertions. Regression equations predicting maximum exerted trunk moments were developed from anthropometric measurements of 120 subjects. In addition, 20 subjects performed sub-maximal and maximal exertions to determine the necessary characteristic exertions needed for normalization purposes. For most of the trunk muscles, a highly linear relationship was found between EMG muscle activity and trunk moment exerted. This analysis determined that an EMG-moment reference point can be obtained via a set of sub-maximal exertions in combination with a predicted maximal exertion (expected maximum contraction or EMC) based upon anthropometric measurements. This normalization technique overcomes the limitations of the subjective nature for the MVC method providing a viable assessment method of individuals with a low back injury or those unwilling to exert an MVC as well as could be extended to other joints/muscles.
Article
The influence of a core-strengthening program on low back pain (LBP) occurrence and hip strength differences were studied in NCAA Division I collegiate athletes. In 1998, 1999, and 2000, hip strength was measured during preparticipation physical examinations and occurrence of LBP was monitored throughout the year. Following the 1999-2000 preparticipation physicals, all athletes began participation in a structured core-strengthening program, which emphasized abdominal, paraspinal, and hip extensor strengthening. Incidence of LBP and the relationship with hip muscle imbalance were compared between consecutive academic years. After incorporation of core strengthening, there was no statistically significant change in LBP occurrence. Side-to-side extensor strength between athletes participating in both the 1998-1999 and 1999-2000 physicals were no different. After core strengthening, the right hip extensor was, on average, stronger than that of the left hip extensor (P = 0.0001). More specific gender differences were noted after core strengthening. Using logistic regression, female athletes with weaker left hip abductors had a more significant probability of requiring treatment for LBP (P = 0.009) The impact of core strengthening on collegiate athletes has not been previously examined. These results indicated no significant advantage of core strengthening in reducing LBP occurrence, though this may be more a reflection of the small numbers of subjects who actually required treatment. The core program, however, seems to have had a role in modifying hip extensor strength balance. The association between hip strength and future LBP occurrence, observed only in females, may indicate the need for more gender-specific core programs. The need for a larger scale study to examine the impact of core strengthening in collegiate athletes is demonstrated.
Article
A cross-sectional study was conducted. To determine the activity of the deep and superficial fibers of the lumbar multifidus during voluntary movement of the arm. The multifidus contributes to stability of the lumbar spine. Because the deep and superficial parts of the multifidus are near the center of lumbar joint rotation, the superficial fibers are well suited to control spine orientation, and the deep fibers to control intervertebral movement. However, there currently are limited in vivo data to support this distinction. Electromyographic activity was recorded in both the deep and superficial multifidus, transversus abdominis, erector spinae, and deltoid using selective intramuscular electrodes and surface electrodes during single and repetitive arm movements. The latency of electromyographic onset in each muscle during single movements and the pattern of electromyographic activity during repetitive movements were compared between muscles. With single arm movements, the onset of electromyography in the erector spinae and superficial multifidus relative to the deltoid was dependent on the direction of movement, but the onset in the deep multifidus and transversus abdominis was not. With repetitive arm movements, peaks in superficial multifidus and erector spinae electromyography occurred only during flexion for most subjects, whereas peaks in deep multifidus electromyography occurred during movement in both directions. The deep and superficial fibers of the multifidus are differentially active during single and repetitive movements of the arm. The data from this study support the hypothesis that the superficial multifidus contributes to the control of spine orientation, and that the deep multifidus has a role in controlling intersegmental motion.
Article
Two abdominal muscle patterns were tested in the same group of individuals, and their effects were compared in relation to sacroiliac joint laxity. One pattern was contraction of the transversus abdominis, independently of the other abdominals; the other was a bracing action that used all the lateral abdominal muscles. To demonstrate the biomechanical effect of the exercise for the transversus abdominis known to be effective in low back pain. Drawing in the abdominal wall is a specific exercise for the transversus abdominis muscle (in cocontraction with the multifidus), which is used in the treatment of back pain. Clinical effectiveness has been demonstrated to be a reduction of 3-year recurrence from 75% to 35%. To the authors' best knowledge, there is not yet in vivo proof of the biomechanical effect of this specific exercise. This study of a biomechanical model on the mechanics of the sacroiliac joint, however, predicted a significant effect of transversus abdominis muscle force. Thirteen healthy individuals who could perform the test patterns were included. Sacroiliac joint laxity values were recorded with study participants in the prone position during the two abdominal muscle patterns. The values were recorded by means of Doppler imaging of vibrations. Simultaneous electromyographic recordings and ultrasound imaging were used to verify the two muscle patterns. The range of sacroiliac joint laxity values observed in this study was comparable with levels found in earlier studies of healthy individuals. These values decreased significantly in all individuals during both muscle patterns (P < 0.001). The independent transversus abdominis contraction decreased sacroiliac joint laxity (or rather increased sacroiliac joint stiffness) to a significantly greater degree than the general abdominal exercise pattern (P < 0.0260). Contraction of the transversus abdominis significantly decreases the laxity of the sacroiliac joint. This decrease in laxity is larger than that caused by a bracing action using all the lateral abdominal muscles. These findings are in line with the authors' biomechanical model predictions and support the use of independent transversus abdominis contractions for the treatment of low back pain.
Article
The intra-subject repeatability of measuring the three dimensional (3D) angular kinematics of the lumbo-pelvic-hip complex during running was evaluated. Spatio-temporal parameters were found to be repeatable. All angular kinematic parameters displayed high within-day repeatability despite numerous potential sources of variability in the data. Most angular kinematic parameters also displayed high between-day and overall repeatability, except for trunk flexion-extension, lumbar spine flexion-extension, pelvic anterior-posterior tilt, hip axial rotation and thigh axial rotation. These angular parameters were highly susceptible to marker reapplication errors that produced static daily offsets in the data. Overall, the results of this study suggest that the 3D angular kinematic patterns of the lumbo-pelvic-hip complex during running can be measured with sufficient repeatability to justify the implementation of the method as an evaluation tool in future investigations. However, caution must be exerted when interpreting the absolute magnitudes of trunk flexion-extension, lumbar spine flexion-extension, pelvic anterior-posterior tilt, hip axial rotation and thigh axial rotation, given the poor level of repeatability found for these measures.
Article
Objective: To describe patterns of muscle activation during gait in selected abdominal and lumbar muscles using cluster analysis. Participants: A sample of convenience of 38 healthy adult volunteers. Outcome measures. Electromyographic activity from the right internal and external obliques, rectus abdominis and lumbar erector spinae were recorded, and the root mean square values for each muscle were calculated throughout the stride in 5% epochs. These values were normalised to maximum effort isometric muscle contractions. Cluster analysis was used to identify groups of subjects with similar patterns of activity and activation levels. Results: Cluster analysis identified two patterns of activity for the internal oblique, external oblique and rectus abdominis muscles. In the lumbar erector spinae, three patterns of activity were observed. In most instances, the patterns observed for each muscle differed in the magnitude of the activation levels. In rectus abdominis and external oblique muscles, the majority of subjects had low levels of activity (<5.0% of a maximum voluntary contraction) that were relatively constant throughout the stride cycle. In the internal oblique and the erector spinae muscles, more distinct bursts of activity were observed, most often close to foot-strike. The different algorithms used for the cluster analysis yielded similar results and a discriminant function analysis provided further evidence to support the patterns observed. Conclusions: Cluster analysis was useful in grouping subjects who had similar patterns of muscle activity. It provided evidence that there were subgroups that might otherwise not be observed if a group ensemble was presented as the "norm" for any particular muscle's role during gait. Relevance: The identification of common variations in muscle activity may prove valuable in identifying individuals with electromyographic patterns that might influence their chances of sustaining injury. Alternatively, clusters may provide important information related to muscle activity in those that do well or otherwise after a particular injury.
Article
The objective of this study were to: (i) describe the typical three-dimensional (3D) angular kinematics of the lumbar spine and pelvis during running and; (ii) assess whether the movements of the lumbar spine and pelvis during running are coordinated. A cohort of 20 non-injured male runners who usually ran >20 km/week were voluntarily recruited. All trials were conducted on a treadmill at a running speed of 4.0 m/second. Reflective markers were placed over anatomical landmarks of the thoraco-lumbar spine and pelvis. Data were captured using a VICON motion analysis system. The lumbar spine and pelvis both displayed complex 3D angular kinematic patterns during running. High correlations were found for the comparisons of flexion-extension of the lumbar spine with anterior-posterior tilt of the pelvis (r=-0.84) and lateral bend of the lumbar spine with obliquity of the pelvis (r=-0.75). However, a poor correlation was found for the comparison of axial rotation of the lumbar spine with axial rotation of the pelvis (r=0.37). A phase difference of 21% of the running cycle was evident between axial rotation of the lumbar spine and pelvis. The identified coordinated kinematic patterns of the lumbar spine and pelvis during running serve as a basis for future investigations exploring the relationship between atypical kinematic patterns and injury.
Article
The purpose of this study was to compare four different methods of normalising electromyograms (EMGs) recorded during normal gait. Comparisons were made between the amplitude, intra-individual variability and inter-individual variability of EMGs. Surface EMGs were recorded from the biceps femoris, semitendinosus, vastus lateralis and vastus medialis of ten males and two females while they walked on a treadmill at a self-selected speed. EMGs from the same muscles were subsequently recorded during isometric maximal voluntary contractions (MVCs) and concentric, isokinetic MVCs that were performed between 0.52 and 7.85 rad x s(-1) on a BIODEX dynamometer. EMGs were also recorded during eccentric, isokinetic MVCs between 0.52 and 2.62 rad x s(-1). Gait EMGs were then normalised at 2% intervals of the gait cycle by expressing them as a percentage of the following reference values: the mean (mean dynamic method) and the peak (peak dynamic method) EMG from the intra-individual ensemble average; the EMG from an isometric MVC (isometric MVC method); and the EMG from an isokinetic MVC that occurred with the same muscle action, length and velocity of musculotendinous unit as the gait EMGs (isokinetic MVC method). The isokinetic MVC method produced significantly greater (P<0.05) intra-individual variability compared to the other methods when it was measured using the variance ratio. Inter-individual variability of gait EMGs, again measured using the variance ratio, was also greatest when they were normalised using the isokinetic MVC method. The pattern and amplitude of EMGs normalised using the isometric MVC method and the isokinetic MVC method were very similar (root mean square difference and absolute difference both less than 3%). It was concluded that the isokinetic MVC method should not be adopted by gait researchers or clinicians as it does not reduce intra- or inter-individual variability anymore than existing normalisation methods, nor does it provide a more representative measure of muscle activation during gait than the isometric MVC method.
Article
In vivo porcine study of intervertebral kinematics. This study investigated the effect of transversus abdominis and diaphragm activity, and increased intra-abdominal pressure on intervertebral kinematics in porcine lumbar spines. Studies of trunk muscle recruitment in humans suggest that diaphragm and transversus abdominis activity, and the associated intra-abdominal pressure contribute to the control of intervertebral motion. However, this has not been tested in vivo. Relative intervertebral motion of the L3 and L4 vertebrae and the stiffness at L4 were measured in response to displacements of the L4 vertebra imposed via a device fixed to the L4 vertebral body. In separate trials, diaphragm and transversus abdominis activity was evoked by stimulation of the phrenic nerves and via electrodes threaded through the abdominal wall. When intra-abdominal pressure was increased by diaphragm or transversus abdominis stimulation, the relative intervertebral displacement of the L3 and L4 vertebrae was reduced and the stiffness of L4 was increased for caudal displacements. There was no change in either parameter for rostral displacements. In separate trials, the diaphragm crurae and the fascial attachments of transversus abdominis were cut, but intra-abdominal pressure was increased. In these trials, the reduction in intervertebral motion was similar to trials with intact attachments for caudal motion, but was increased for rostral trials. The results of these studies indicate that elevated intra-abdominal pressure, and contraction of diaphragm and transversus abdominis provide a mechanical contribution to the control of spinal intervertebral stiffness. Furthermore, the effect is modified by the muscular attachments to the spine.