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Abdominal and erector spinae muscle activity during gait: The use of cluster analysis to identify patterns of activity
Abstract
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.
... The participants were also evaluated for changes in the electromyographic activi of the four trunk muscles, depending on gait posture, while walking on a treadmill [1, Many previous studies have used a human average walking speed of 4 km however, this speed was thought to be dangerous when we tested walking in kyph and sway-back postures on the treadmill. Therefore, the walking speed was determi to be 3 km/h, within a non-dangerous range [21]. ...
... Many previous studies have used a human average walking speed of 4 km/h; however, this speed was thought to be dangerous when we tested walking in kyphotic and sway-back postures on the treadmill. Therefore, the walking speed was determined to be 3 km/h, within a non-dangerous range [21]. ...
... In gait movements, the trunk muscles play a crucial role in generating and regulating the motion between the trunk and pelvis [2,21]. Trunk muscles also play a role in balancing the trunk on the pelvis [27]. ...
Background and Objectives: Many people tend to carry their bags or baggage on only one side of their body. Due to smartphone use, people also tend to walk bent forward in a kyphotic posture. In this study, we aimed to assess trunk muscle activity changes due to weight-bearing, carried in the left or right hand, and using three different gait postures. Materials and Methods: We recruited 27 healthy participants (aged 19–75 years) with no history of LBP within the last 6 months before study participation. Electromyographic activities of the lower back and the abdominal muscles of the participants were evaluated using four-channel surface electromyography (EMG). Surface EMG recordings were obtained from four trunk muscles, including the flexor (rectus abdominis (RA), external oblique (EO)) and extensor muscles (lumbar erector spinae (LE), and the superficial lumbar multifidus (LM)), during unilateral weight-bearing tasks and with different gait postures (normal gait, with a sway back, and thoracic kyphosis). Results: In the “unilateral weight-bearing task”, there was a significant difference in the activity of all the trunk muscles between the weight-bearing limb side and the opposite side (p < 0.05). The activation of the left trunk muscle was greater than that of the right trunk muscle when the dumbbell was lifted using the right hand. The other side showed the same result. In the “gait posture task” performed by the participants using a sway-back posture, the RA and EO had a higher level of activity in the stance and swing phases compared with that in a neutral gait (p < 0.05). Moreover, in the participants with a thoracic kyphosis posture, the LE and LM had a higher level of activity compared with that in a neutral gait (p < 0.05). Conclusions: Our results indicate that abnormal gait posture and unilateral weight-bearing tasks may impair the balance of trunk muscles, increasing the incidence of LBP. However, further large-scale, prospective, controlled studies are warranted to corroborate our results.
... We re-examined our previously published dataset initially analyzed with a standard group ensemble statistical average method (Hachard et al. 2020) to (1) form a classification system of MF levels and balance control impairments using a hierarchical cluster analysis (HCA); and (2) determine whether balance control impairments were related to participants' MF levels. Cluster analysis is a multivariate statistical method which places individuals into a cluster that contains other individuals with similar characteristics thus enabling the identification of natural groupings that may exist in a population (White and McNair 2002). It was hypothesized that participants who performed the same prolonged continuous demanding cognitive task would not demonstrate a similar level of MF thus engendering different levels of impairment on balance control. ...
... A hierarchical cluster analysis (HCA) was performed to classify participants' behavior into subgroups with similar characteristics (Watelain et al. 2000;White and McNair 2002). This analysis is a multivariate statistical method which places individuals into a cluster that contains other individuals with similar characteristics thus enabling the identification of natural groupings that may exist in a population (White and McNair 2002). ...
... A hierarchical cluster analysis (HCA) was performed to classify participants' behavior into subgroups with similar characteristics (Watelain et al. 2000;White and McNair 2002). This analysis is a multivariate statistical method which places individuals into a cluster that contains other individuals with similar characteristics thus enabling the identification of natural groupings that may exist in a population (White and McNair 2002). Data from the NASA-TLX test, AX-CPT and balance control assessments were independently analyzed to produce three separated cluster classifications: NASA-TLX clusters, AX-CPT clusters and balance clusters. ...
This study investigated the effects of mental fatigue (MF) induced by a 90-min AX-continuous performance test (AX-CPT) on balance control by addressing the issue of the heterogeneity of individuals’ responses. Twenty healthy young active participants were recruited. They had to carry out two balance tasks (sway as little as possible on a stable support with the eyes open and closed) when standing on a force platform before and after performing a 90-min AX-CPT. The NASA-TLX test was used to assess the subjective manifestations of MF. Objective cognitive performance was measured using results from the AX-CPT. Inter-individual differences in behavioral deterioration due to MF were analyzed with a hierarchical cluster analysis, which categorizes participants’ behaviors into subgroups with similar characteristics. The cluster analysis revealed that the achievement of the AX-CPT induced various levels of MF and balance impairments within the whole sample. A significant relationship between the level of MF and the degree of balance disturbance was observed only when participants stood with the eyes open, thus suggesting that inter-individual differences in vulnerability to MF could stem from differences between subjects in the level of engagement of visual attention and/or from differences in field dependency for balance control. These findings show that the completion of the same prolonged demanding cognitive task induces a strong heterogeneity in subjects’ responses, with marked individual differences in MF vulnerability that affect balance control differently according to the sensory context.
... Such predictions would in turn require estimating post-surgery forces generated by muscles spanning the lower trunk and all lower extremity joints. However, predicting trunk and leg muscle forces concurrently during walking based on EMG data remains challenging, since the limited number of experimental EMG channels are typically used to measure the activity of leg muscles, with EMG data rarely being collected from trunk muscles as well during walking (Callaghan et al., 1999;White and McNair, 2002;Anders et al., 2007). ...
... The two muscle synergies were both recruited by the lumbar extensors ES and MF. This observation was also consistent with the reported activation of ES during footstrikes (White and McNair, 2002). Due to the emergence of such synergies, trunk muscles no longer needed to recruit all the synergies made available to them by lower extremity muscles. ...
One of the surgical treatments for pelvic sarcoma is the restoration of hip function with a custom pelvic prosthesis after cancerous tumor removal. The orthopedic oncologist and orthopedic implant company must make numerous often subjective decisions regarding the design of the pelvic surgery and custom pelvic prosthesis. Using personalized musculoskeletal computer models to predict post-surgery walking function and custom pelvic prosthesis loading is an emerging method for making surgical and custom prosthesis design decisions in a more objective manner. Such predictions would necessitate the estimation of forces generated by muscles spanning the lower trunk and all joints of the lower extremities. However, estimating trunk and leg muscle forces simultaneously during walking based on electromyography (EMG) data remains challenging due to the limited number of EMG channels typically used for measurement of leg muscle activity. This study developed a computational method for estimating unmeasured trunk muscle activations during walking using lower extremity muscle synergies. To facilitate the calibration of an EMG-driven model and the estimation of leg muscle activations, EMG data were collected from each leg. Using non-negative matrix factorization, muscle synergies were extracted from activations of leg muscles. On the basis of previous studies, it was hypothesized that the time-varying synergy activations were shared between the trunk and leg muscles. The synergy weights required to reconstruct the trunk muscle activations were determined through optimization. The accuracy of the synergy-based method was dependent on the number of synergies and optimization formulation. With seven synergies and an increased level of activation minimization, the estimated activations of the erector spinae were strongly correlated with their measured activity. This study created a custom full-body model by combining two existing musculoskeletal models. The model was further modified and heavily personalized to represent various aspects of the pelvic sarcoma patient, all of which contributed to the estimation of trunk muscle activations. This proposed method can facilitate the prediction of post-surgery walking function and pelvic prosthesis loading, as well as provide objective evaluations for surgical and prosthesis design decisions.
... Feature optimisation can be a subject of future investigation. Nonetheless, the large number of parameters extracted on a small number of subjects was in line with the state of the art describing application of data mining methods for the classification of gait parameters [19,[41][42][43]. Even though some of the present findings are contradictory with the current literature [9], it should be mentioned that previous studies compared subjects based on the diagnosis of DN, whilst the current study compared subjects based on the clustering results. ...
... Moreover, by using parameters derived from both envelope and onset and offset analyses, a better classification of subjects is provided. In particular, the classification of DNS into two different clusters finds agreement with previous studies that detected different patterns in this population at the level of joint kinematics [11], kinetics, and plantar pressure [15,43]. These results can be adopted on one hand as a support for clinical decision making, on the other one to plan studies aiming at detecting differences between diabetic subjects and other cohorts. ...
The aim of this work was twofold: on one side to determine the most suitable parameters of surface electromyography (sEMG) to classify diabetic subjects with and without neuropathy and discriminate them from healthy controls and second to assess the role of the task acquired in the classification process. For this purpose 30 subjects were examined (10 controls, 10 diabetics with and 10 without neuropathy) whilst walking and stair ascending and descending. The electrical activity of six muscles was recorded bilaterally through a 16-channel sEMG system synchronised with a stereophotogrammetric system: Rectus Femoris, Gluteus Medius, Tibialis Anterior, Peroneus Longus, Gastrocnemius Lateralis and Extensor Digitorum. Spatiotemporal parameters of gait and stair climbing and the following sEMG parameters were extracted: signal envelope, activity duration, timing of activation and deactivation. A hierarchical clustering algorithm was applied to the whole set of parameters with different distances and linkage methods. Results showed that only by applying the Ward agglomerative hierarchical clustering (Hamming distance) to the all set of parameters extracted from both tasks, 5 well-separated clusters were obtained: cluster 3 included only DS subjects, cluster 2 and 4 only controls and cluster 1 and 5 only DNS subjects. This method could be used for planning rehabilitation treatments.
Graphical abstract
... Phasic muscle activity in the paraspinals occurs bilaterally at initial contact and during the double support phases of the gait cycle [105,106]. 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]. ...
... 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. ...
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.
... To this end, a hierarchical cluster analysis was performed. The clustering analysis is a multivariate statistical method which categorizes the participants' behaviors into subgroups with similar characteristics, thus facilitating the investigation of differences in individual responses by enabling the identification of natural groupings that may exist in a whole sample (Watelain et al., 2000;White and McNair, 2002). It was hypothesized that the wearing of compression garments differently affected balance control in active subjects. ...
... A hierarchical cluster analysis was performed in a second step to classify the participants' behavior into subgroups with similar characteristics (Watelain et al., 2000;White and McNair, 2002). A normalized principal component analysis was first used to reduce the dimensionality of the data prior to performing the hierarchical cluster analysis based on the five first principal component scores. ...
There is controversy about the influence of compression garments on balance control. A positive influence was reported in elderly and injured individuals, whereas no beneficial effects were observed in young healthy active subjects, which is likely due to the large
inter-individual differences in these subjects. Hence, this study investigated the acute effects of compression garments on balance control in young healthy active subjects by addressing the issue of heterogeneity of individuals’ responses to the wearing of compression garments. Thirteen young, healthy, active subjects were recruited. They stood on a force plate which recorded the center of foot pressure displacements in a monopedal stance with the eyes closed and on a wobble board with the eyes open, while wearing compression garments or not. Statistics were first calculated with the data from the whole sample. A hierarchical cluster analysis was also performed in order to categorize the participants’ behaviors into subgroups with similar characteristics. The whole group analysis showed that there were no significant effects attributed to compression garments. The clustering analysis identified distinct and homogeneous subgroups of participants. Only participants who swayed the more at baseline benefited from the wearing of compression garments to improve their balance control. These participants might have either a gravity-dependent preferred sensorimotor strategy with
an exploratory postural behavior or poorer balance/proprioceptive abilities. Since poor balance control is a predictor of sports injury risk, wearing compression garments during sports practice could be viewed as a potential prevention strategy for individuals at risk.
Full text: https://www.frontiersin.org/articles/10.3389/fnhum.2020.582514/full
... It has been reported that enhanced activity of rectus abdominis and erector spinae during stability-enhancing exercise programmes leads to significant enhancement in cooperative spine/core muscle activity and stability 16) . Furthermore, both rectus abdominis and erector spinae contribute to the normal gait by generating and controlling the motion between the trunk and pelvis 17,18) . Hence sufficient activation of these muscles is important in decreasing body's vertical displacement (involving knees) and producing a smoother trajectory for the centre of mass during the gait cycle 17) . ...
... Furthermore, both rectus abdominis and erector spinae contribute to the normal gait by generating and controlling the motion between the trunk and pelvis 17,18) . Hence sufficient activation of these muscles is important in decreasing body's vertical displacement (involving knees) and producing a smoother trajectory for the centre of mass during the gait cycle 17) . ...
[Purpose] Most of rehabilitation programmes for Anterior Cruciate Ligament (ACL) injury focus on quadriceps-hamstrings activation imbalances and less is known about kinetically linked muscles. This study investigated electromyographic activity of selected trunk, core, and thigh muscles during common rehabilitation exercises for ACL injury. [Subjects and Methods] Twelve active female volunteers participated in this cross-sectional laboratory study. Surface EMG was used to compare activation of eight trunk, hip/core, and lower limb muscles: Erector Spinae (ES), Rectus Abdominis (RA), Gluteus Maximus (GM), Vastus Lateralis (VL), Rectus Femoris (RF), Vastus Medialis (VM), Biceps Femoris (BF), and Semitendinosus (ST) during Forward Lunge, Double Leg Raise, Glute Bridge, Sit-Up, and Squat. [Results] Forward lunge produced significantly higher activation in the VM (61.1 ± 19.4), VL (59.2 ± 12.9), and RF (32.0 ± 2.6). Double leg raise generated highest activity in the RF (26.6 ± 2.8) and RA (43.3 ± 4.4); and Glute Bridge in the GM (44.5 ± 19.0) and BF (22.4 ± 4.3). Sit-up produced the highest activation in the RF (36.6 ± 4.7) followed by RA (18.9 ± 3.8). Squat produced a higher activation in VL (55.0 ± 12.9), VM (51.5 ± 18.2), and ES (40.4 ± 18.3). [Conclusion] This study provide further evidence for developing training programmes for ACL injury prevention and rehabilitation. A combination of exercises to reinstate quadriceps-hamstrings activation balance and enhance core stability is recommended.
... Normal gait is important to maintain harmonious trunk and pelvic turns. The dynamic balance of trunk muscle activities reduces unnecessary energy consumption and effectively eliminates false steps that may occur during gait 4) . ...
... Normal gait is important to maintain harmonious trunk and pelvic movements. The dynamic balance of trunk muscle activities limits unnecessary energy consumption and effectively reduces false steps that may occur during gait 4) . Incorrect gait patterns cause body instability and affect breathing, the heart, and balance of various regions of the body. ...
[Purpose] This study investigated the effects of pelvic adjustment on pelvic posture and lower limb joint angles during walking in female university students. [Subjects] Thirty healthy female university students were randomly assigned to an experimental group (pelvic adjustment group, n = 15) and a control group (stretching group, n = 15). [Methods] Pelvic adjustment was performed three times on the experimental group. The control group performed three sets of pelvic muscle stretching for 15 minutes. A back mapper and motion analysis equipment were used to measure pelvic posture and angles of lower limb joints for the experimental and control group. [Results] The values obtained before and after the intervention were compared. For the experimental group, the results were significantly different in terms of reduced differences in hip flexion between the left and right hips and in knee abduction between the left and right knees. Differences in pelvic position and pelvic torsion were also found in the experimental group. No significant differences in the control group were identified. [Conclusion] Pelvic adjustment affects pelvic position and torsion and this enhancement to pelvic stability decreases hip flexion and knee abduction during walking. © 2016 The Society of Physical Therapy Science. Published by IPEC Inc.
... Although there were significant increases in the activation of the rectus abdominis and anterior deltoid caused by the increase in speed during the test, it should be noted that there were no significant differences compared to the placebo garment. Regardless of wearing the elastomeric garment or the placebo, the evolution of muscle activation during the test coincided with previous studies (White and McNair, 2002). These authors indicate that the increase of trunk muscle activity during walking and slow running is low (0%-40%). ...
Background: The use of elastomeric technology in sports garments is increasing in popularity; however, its specific impact on physiological and psychological variables is not fully understood. Thus, we aimed to analyze the physiological (muscle activation of the pectoralis major, triceps brachii, anterior deltoid, and rectus abdominis, capillary blood lactate, systolic and diastolic blood pressure, and heart rate) and psychological (global and respiratory rating of perceived exertion [RPE]) responses during an incremental treadmill test wearing a new sports garment for the upper body that incorporates elastomeric technology or a placebo garment.
Methods: Eighteen physically active young adults participated in two randomized sessions, one wearing the elastomeric garment and the other wearing a placebo. Participants performed in both sessions the same treadmill incremental test (i.e., starting at 8 km/h, an increase of 2 km/h each stage, stage duration of 3 min, and inclination of 1%; the test ended after completing the 18 km/h Stage or participant volitional exhaustion). The dependent variables were assessed before, during, and/or after the test. Nonparametric tests evaluated differences.
Results: The elastomeric garment led to a greater muscle activation (p < 0.05) in the pectoralis major at 16 km/h (+33.35%, p = 0.01, d = 0.47) and 18 km/h (+32.09%, p = 0.02, d = 0.55) and in the triceps brachii at 10 km/h (+20.28%, p = 0.01, d = 0.41) and 12 km/h (+34.95%, p = 0.04, d = 0.28). Additionally, lower lactate was observed at the end of the test (−7.81%, p = 0.01, d = 0.68) and after 5 min of recovery (−13.71%, p < 0.001, d = 1.00) with the elastomeric garment. Nonsignificant differences between the garments were encountered in the time to exhaustion, cardiovascular responses, or ratings of perceived exertion.
Conclusion: These findings suggest that elastomeric garments enhance physiological responses (muscle activation and blood lactate) during an incremental treadmill test without impairing physical performance or effort perception.
... The reason behind it is reduction in voluntary muscle contractions and reflexes and timing of movement onset. 9 As compared to flat soles, high heel shoes have been reported to result in an increase in vertical and anterior-posterior ground reaction force (GRF), that ultimately can affect the lumber spine. 10 Another study reported correlation of high heeled shoes and imbalances of body among female college students. ...
Background & objective: Persistent hyperglycemia is the driving force for the progression of diabetic vascular complications and inflammatory response. S100A8 and S100A9 are small calcium-binding proteins involved in various cellular processes, including inflammation and immune responses. Tristetraprolin (TTP), alternatively known as zinc finger protein 36, acts as an RNA-binding molecule that has an important role in regulating the expression of messenger RNAs containing AU-rich elements. We aimed to address the involvement of inflammatory mediators like S100A8/A9 proteins and, RNA-binding proteins, in microvascular complications of type 2 diabetes mellitus (T2DM). Methodology: The study was conducted from October 2022 to April 2023. We enrolled 200 subjects in this study involved in five equal groups: T2DM, diabetic nephropathy (DN), diabetic retinopathy (DR), diabetic neuropathy (DNR) and 40 normal healthy subjects as control group. CBC analysis was performed directly using the hematology analyzer CBC (Sysmex, Japan) technique. Serum S100 A8/A9 were measured by ELISA, and TTP gene expression was measured by RT-qPCR. Results: The study's findings revealed a notable increase in neutrophil/lymphocytes ratio (NLR) and S100A8/A9 levels in patients groups compared to the healthy group (P < 0.05), while decreased TTP mRNA expression was observed in all patient groups compared to control (P < 0.05) Conclusion: An increase in S1008A/9A levels with down regulation of anti-inflammatory binding protein (TTP) in patients suffering from type 2 diabetes mellitus with diabetic nephropathy, diabetic retinopathy, or diabetic neuropathy, suggests to be the therapeutic targets to regulate inflammatory response in type 2 diabetes mellitus and its complications. Abbreviations: T2DM - Type 2 Diabetes Mellitus; DN - Diabetic Nephropathy; DR - Diabetic Retinopathy; DNR - Diabetic Neuropathy; NLR- Neutrophil/Lymphocyte Ratio; TTP - Tristetraprolin Key words: Diabetes Mellitus; Inflammation; S100A8/A9; Inflammation; RNA-binding protein; T2DM; Neutrophil/Lymphocyte Ratio Citation: Sarhan A, Almzaiel AJ, Majeed Alrufaie MM. Potential role of S100A8/A9 and RNA-binding protein in microvascular complications of type2 diabetes mellitus. Anaesth. pain intensive care 2023;27(6):673−680. DOI: 10.35975/apic.v27i6.2338 Received: August 15, 2023; Reviewed: September 03, 2023; Accepted: September 15, 2023
... The reason behind it is reduction in voluntary muscle contractions and reflexes and timing of movement onset. 9 As compared to flat soles, high heel shoes have been reported to result in an increase in vertical and anterior-posterior ground reaction force (GRF), that ultimately can affect the lumber spine. 10 Another study reported correlation of high heeled shoes and imbalances of body among female college students. ...
Background & Objective: High heels of shoes are preferred for attractiveness, but are detrimental to health regarding their biomechanics. High heel changes the joint mechanics during walking which may result in abnormal stress and pressure at certain points and thus lead to painful knee, foot, hip or low back pain. The objective of this systematic review was to evaluate the literature addressing the association between the high heeled shoes and low back pain among females. Methodology: It was a systemic review conducted during 2014-2020 on databases including Cochrane Library, PubMed, Medline, PEDro and Scopus, with key words ‘Low back pain’ OR ‘Back pain OR Lumbago’, ‘Low back pain in females OR Back pain in females OR Lumbago in females’, ‘High heeled shoes OR High heels’, ‘Association OR relationship’. Available full-length papers in English language were explored, after the screening and quality assessment using Axis critical appraisal tool for the studies. Results: We found 32 articles, but the inclusion criteria were met only by 11 studies in quality score of 16. 27/20. The eligible studies enrolled a total of 1334 female participants with an average age of 18-32 y. Nine studies explained that low back pain was associated with high heeled shoes but none specified height of the heel, and only a range of 2.5-11 cm was suspected to be associated with changes in lumber biomechanics or lordosis, that can exert extra pressure for postural adjustments and lead to low back pain. Conclusion: Out of 11 studies, nine studies favored that low back pain was associated with high heeled shoes, there was no specific height mentioned; but only a range of 2.5-11 cm was found to be associated with biomechanical changes due to postural adjustments, being a possible cause of low back pain among females. Key words: Association; Females; High Heel; Low Back Pain; Shoes Citation: Younas AS, Tanveer F, Sharif F, Waseem I, Mahmood W, Ahmad A. Association of low back pain with the use of high heel in ladies: a systematic review. Anaesth. pain intensive care 2023;27(6):681−688. DOI: 10.35975/apic.v27i6.2339 Received: June 20, 2022; Revised: July 07, 2023; Accepted: November 08, 2023
... Previous studies have shown that the EMG activity of the RAB is relatively low (<5% of MIVC) throughout the gait cycle of level walking, contributing minimally to the stabilization of the trunk [54]. Other investigators showed that uphill walking on a treadmill at a 7 • slope [55] with the preferred speed (the highest speed at which the participants could walk naturally) or ascending a ramp with a slope of 15 • [23] did not alter RAB activation compared to level walking. ...
INTRODUCTION:
Postural control refers to the mechanism based on which the central nervous system regulates the stimuli from the sensory organs in maintaining body stability. When postural control is jeopardized by changes in the intrinsic (e.g. omatosensory) and/or extrinsic stimuli (e.g. environment) body stability is challenged increasing the likelihood of injury. It is generally accepted that a condition that may affect postural control and elicit a wide range of musculoskeletal low back and limb injuries is load transfer. However, postural control may be further aggravated when a load is required to be transferred in different ways and/or on inclined surfaces. This study
aimed to assess the effects of load transfer by means of a front- or a backpack on postural control during walking on inclined surfaces.
METHODS: Thirty asymptomatic, skeletal symmetric individuals aged 20-30 years participated in the study. Postural control was assessed by means of (i) the EMG activity of the neck, thoracic and lumbar extensors (NE, TE, and LE) and trunk flexors (TF) and (ii) the anteroposterior and mediolateral displacement as well as the ellipse area of CoP during treadmill based uphill walking at a constant speed of 5 km/h. Participants had to walk for 10 minutes, during which the slope of the treadmill gradually increased every 2.5 minutes from 0 to 15 degrees, at 5-degree intervals, without and with carrying a front pack or a backpack equal to 15% of each
individuals body weight. A device for recording physiological signals and an inertial sensor placed on the upper torso were used to assess the EMG activity of the muscles under investigation and the displacement of the CoP, respectively.
RESULTS: Significant differences between inclinations and ways of load carriage were obtained for the EMG activity of NE (p<0.001), TE (p<0.001), and LE (p<0.001) as well as TF (p<0.01). The EMG activity of the muscles tested increased as the slope increased and it was greater when the participants walk carrying a front pack compared to a backpack or no load. Similarly, the anteroposterior displacement and ellipse area of CoP was significantly increased as the slope of the treadmill’s surface increased (p<0.001) regardless of the way used to carry the load. The greatest anteroposterior displacement and ellipse area of CoP were obtained while walking carrying a front pack as opposed to carrying a backpack or no load. The differences between inclinations and ways of load transfer for the mediolateral displacement of CoP were not significant.
CONCLUSION: Carrying a backpack remains the least provocative way of load transfer when an individual walks on a level or a sloped surface, at least as far as the EMG activity of the trunk musculature and the displacements of CoP are concerned. Carrying a front pack under the same surface conditions should be limited, as it significantly disrupts postural control predisposing an individual to injury
... Previous studies have shown that the EMG activity of the RAB is relatively low (<5% of MIVC) throughout the gait cycle of level walking, contributing minimally to the stabilization of the trunk [54]. Other investigators showed that uphill walking on a treadmill at a 7° slope [55] with the preferred speed (the highest speed at which the participants could walk naturally) or ascending a ramp with a slope of 15° [23] did not alter RAB activation compared to level walking. ...
Load carriage and uphill walking are conditions that either individually or in combination can compromise postural control and gait eliciting several musculoskeletal low back and lower limb injuries. The objectives of this study were to investigate postural control responses and spatiotemporal parameters of gait during level and uphill unloaded (UL), back-loaded (BL), and front-loaded (FL) walking. Postural control was assessed in 30 asymptomatic individuals by simultaneously recording (i) EMG activity of neck, thoracic and lumbar erector spinae, and rectus abdominis, (ii) projected 95% ellipse area as well as the anteroposterior and mediolateral trunk displacement, and (iii) spatiotemporal gait parameters (stride/step length and cadence). Measurements were performed during level (0%) and uphill (5, 10, and 15%) walking at a speed of 5 km h−1 without and with a suspended front pack or a backpack weighing 15% of each participant’s body weight. The results of our study showed that postural control, as indicated by increased erector spinae EMG activity and changes in spatiotemporal parameters of gait that manifested with decreased stride/step length and increased cadence, is compromised particularly during level and uphill FL walking as opposed to BL or UL walking, potentially increasing the risk of musculoskeletal and fall-related injuries.
... Internal oblique taping in a side-lying position, an 'i' strip tape was used from the anterior iliac crest to the linea alba with 50% muscle tension to facilitate the io muscle [28]. Since io muscles are continuously active during the stance phase in walking, the affected leg was taped ( Figure 1) [29]. ...
Introduction
Patellofemoral pain syndrome is one of the most common musculoskeletal disorders which mostly affect young females. A widespread treatment for this condition is muscle taping. This study aimed to compare the effect of knee muscle taping versus core muscle taping on balance, pain, and functional activity in patients with patellofemoral pain syndrome.
Methods
Overall, 26 females with patellofemoral pain syndrome were randomly divided into 2 groups: knee muscle taping group ( n = 13) and core muscle taping group ( n = 13). Pain, functional activity, and balance were measured before and 48 hours after the intervention by using the visual analogue scale, Functional Index Questionnaire, and Y Balance Test and Functional Reach Test, respectively.
Results
The within-group comparison showed a significant pain decrease and functional improvement in both groups. However, balance improved significantly only in the core muscle taping group 48 hours after the intervention compared with baseline. The between-group comparison showed no significant difference in variables between the 2 groups at the assessed time points.
Conclusions
Both the knee and core muscle taping treatment caused improvement in pain and functional level of patients with patellofemoral pain syndrome. Also, no superiority of either treatment was demonstrated.
... Other studies have applied clustering analysis and other machine learning techniques to motion capture data to classify different full body actions in healthy individuals [25] or severity of crouch gait in children with cerebral palsy [26]. Electromyography data of the abdominal and erector spinae muscles has also been used as input to clustering algorithms to classify patterns of muscle activity during gait in healthy controls [27]. While a couple of clustering studies have focused on the upper limb prosthesis user population, the application of clustering analysis to compare movement of individuals using multiple prosthetic devices to the movements of non-disabled individuals has not been done. ...
To evaluate movement quality of upper limb (UL) prosthesis users, performance-based outcome measures have been developed that examine the normalcy of movement as compared to a person with a sound, intact hand. However, the broad definition of “normal movement” and the subjective nature of scoring can make it difficult to know which areas of the body to evaluate, and the expected magnitude of deviation from normative movement. To provide a more robust approach to characterizing movement differences, the goals of this work are to identify degrees of freedom (DOFs) that will inform abnormal movement for several tasks using unsupervised machine learning (clustering methods) and elucidate the variations in movement approach across two upper-limb prosthesis devices with varying DOFs as compared to healthy controls. 24 participants with no UL disability or impairment were recruited for this study and trained on the use of a body-powered bypass (n = 6) or the DEKA limb bypass (n = 6) prosthetic devices or included as normative controls. 3D motion capture data were collected from all participants as they performed the Jebsen-Taylor Hand Function Test (JHFT) and targeted Box and Blocks Test (tBBT). Range of Motion, peak angle, angular path length, mean angle, peak angular velocity, and number of zero crossings were calculated from joint angle data for the right/left elbows, right/left shoulders, torso, and neck and fed into a K-means clustering algorithm. Results show right shoulder and torso DOFs to be most informative in distinguishing between bypass user and norm group movement. The JHFT page turning task and the seated tBBT elicit movements from bypass users that are most distinctive from the norm group. Results can be used to inform the development of movement quality scoring methodology for UL performance-based outcome measures. Identifying tasks across two different devices with known variations in movement can inform the best tasks to perform in a rehabilitation setting that challenge the prosthesis user’s ability to achieve normative movement.
... There is no noticeable activity seen by electromyography (EMG) in these muscles. During walking, the rectus abdominis muscle has mean activity of 2% maximal voluntary contraction (MVC) and the external oblique has 5% MVC [24]. As evidenced, this decreased level of core strength activation suggests that despite the reduction of core strength noted in workers (67.64 ± 1.41 mmHg; approximately between grade 1 and 2), it did not relate to their pain intensity level (r = 0.052, p = 0.424) or activity level because strength losses are unlikely to be an issue for spinal stabilization. ...
Objective
To assess the presence of lower back pain (LBP) in automobile industrial workers and correlate it with the factors known to be contributing to the development of work-related lower back pain.
Method
Post ethical approval, an analytical cross-sectional assessment was conducted for a correlation study on 317 workers from different automobile industries, garages and service centres; who were then assessed by Nordic Musculoskeletal Questionnaire for the presence of LBP. Their pain intensity was assessed using a Numerical Rating Scale (NRS), Core strength with pressure biofeedback unit, flexibility via Sitting and Reach test and work posture was assessed with Rapid Entire Body Assessment (REBA) tool. Pain intensity was correlated with core strength, flexibility and posture in all the workers using Spearman’s correlation coefficient (r) with α set at p ≤ 0.05 at 95% Confidence Interval (CI).
Results
There was no significant correlation of the pain intensity with the core strength (r= 0.052, p=0.424), flexibility (r=0.020, p=0.755) or with posture (r=0.002, p=0.974)
Conclusion
The present study concludes that the internal factors like core strength and flexibility, and work postures have no correlation with intensity and severity of lower back pain in automobile industry workers.
... The activation of the core musculature has been suggested to serve a variety of purposes during walking. In nondisabled subjects, sEMG has been used to show that several core muscles are active throughout the gait cycle and that several, including the rectus abdominis (RA), external oblique (EO), and internal oblique (IO), can have increased activation during specific phases, such as midstance or foot-strike [14][15]. ...
... The activation of the core musculature has been suggested to serve a variety of purposes during walking. In nondisabled subjects, sEMG has been used to show that several core muscles are active throughout the gait cycle and that several, including the rectus abdominis (RA), external oblique (EO), and internal oblique (IO), can have increased activation during specific phases, such as midstance or foot-strike [14][15]. ...
The purpose of this study was to investigate core muscle characteristics during walking in patients with multiple sclerosis (MS). Eight patients (4 men) with relapsing-remitting MS (aged 44.9 +/– 8.6 yr) and sex-matched controls (37.9 +/– 8.4 yr) walked on a treadmill for 15 min at a self-selected speed. Positron emission tomography/computed tomography imaging was used to measure core muscle activity immediately after walking based on glucose uptake. Activity was not different between the MS and control group for any of the identified muscles (p > 0.28). Within the MS group, side differences in activity were identified in the lateral flexor group, the external and internal obliques, and the rectus abdominis (p < 0.05), with the less-affected side being activated more. Furthermore, greater muscle volume was found on the more-affected side of the transversus abdominis, quadratus lumborum, and the low-back extensor group (p < 0.03). These muscle characteristics suggest patients with MS utilize compensatory mechanisms during walking to maintain balance and posture. These strategies likely result in increased muscle energy cost and early fatigability. © 2015, Rehabilitation Research and Development Service. All rights reserved.
Background:
Erector spinae plane block (ESPB) can has been used for analgesia after lumbar spine surgery. However, its effect on postoperative quality of recovery (QoR) remains underexplored in patients undergoing transforaminal lumbar interbody fusion (TLIF) or oblique lumbar interbody fusion (OLIF). This study hypothesized that ESPB would improve postoperative QoR in this patient cohort.
Methods:
Patients undergoing TLIF or OLIF were randomized into ESPB (n=38) and control groups (n=38). In the ESPB group, 25 mL of 0.375% bupivacaine was injected into each erector spinae plane at the T12 level under ultrasound guidance before skin incision. Multimodal analgesia, including wound infiltration, was applied in both groups. The QoR-15 score was measured before surgery and 1 day (primary outcome) and 3 days after surgery. Postoperative pain at rest and during ambulation and postoperative ambulation were also evaluated for 3 days after surgery.
Results:
Perioperative QoR-15 scores were not significantly different between the ESPB and control groups including at 1 day after surgery (80±28 vs. 81±25, respectively; P=0.897). Patients in the ESPB group had a significantly lower mean (±SD) pain score during ambulation 1 hour after surgery (7±3 vs. 9±1, respectively; P=0.013) and significantly shorter median (interquartile range) time to the first ambulation after surgery (2.0 [1.0 to 5.5] h vs. 5.0 [1.8 to 10.0] h, respectively; P=0.038). There were no between-group differences in pain scores at other times or in the cumulative number of postoperative ambulations.
Conclusion:
ESPB, as performed in this study, did not improve the QoR after TLIF or OLIF with multimodal analgesia.
Background and Objectives: Cerebral palsy, a term comprises a physical disability in development, which does not spread by contact, mainly in various parts of body and its movements. Children with cerebral palsy have poor gait and reaching movement because of walking difficulty and poor balance control. Core exercises, that it has positive influence on balance and functional mobility. Proprioception exercises have proven to be effective in improving dynamic balance. Many studies have been carried to show the individual effect of proprioceptive exercises and core muscle exercises to improve balance and functional mobility of cerebral palsy children. But there is no evidence showing comparison between core exercises and proprioceptive exercises in children with cerebral palsy. Hence this study aims to see the effects of both treatment and prove which one is better by comparing proprioceptive and core stability exercises. Methods: - A total 60 participants were included in the study out of which 54 completed the study. The participants were divided into two groups. 28 participants were given core stability exercises along with conventional exercises and 26 participants were given proprioceptive training along with conventional exercises. The intervention was given for 8 weeks. Outcomes were taken at the baseline and at the end of 8 weeks. Results: - In this study total 54 subjects, both male (42%) and female (58%) with mean age 8.06+0.80 (Group A) and8.52+1.26 (Group B) were selected using simple random sampling and were allocated into two groups 28 subjects in Group A and 26 subjects in Group B using envelope method. The participants in Group A subjects received core stability exercises along with conventional exercises and Group B received proprioceptive training along with conventional exercises. Between Groups Comparison When the comparison of TUG scores between group A and group B was done unpaired t test, there was no significant difference with p value (>0.05). Thus Group A (core stability exercises) and group B (proprioceptive training) were equally effective in improving functional mobility in children with cerebral palsy at the end of eight weeks intervention which supports the null hypothesis When the comparison of BOT scores between Group A and Group B was done using unpaired t test, there was no significant difference with p value (>0.05). Thus, Group A (core stability exercises) and Group B (proprioceptive training) were equally effective in improving balance in children with cerebral palsy at the end of eight weeks intervention which supports the null hypothesis. Conclusion: - The study concluded that both core exercises and proprioceptive exercises were equally effective in improving functional mobility and balance in children with cerebral palsy at end of 8 weeks’ intervention. In the end, the study revealed no significant differences between the two groups, as both core exercises and proprioceptive exercises resulted in similar improvements in balance and functional mobility in children with cerebral palsy. Core muscle strength is closely linked to lower limb muscle endurance, and strengthening the core can enhance stability in lower limb movements, ensuring smooth and stable motion. On the other hand, proprioceptive training enhances knee stability through various sensory inputs, including muscle spindles, Golgi tendon organs, and joint afferents, all of which contribute to joint position sensing. In conclusion, both core stability exercises and proprioceptive training were found to be effective in improving balance and functional mobility over an 8-week intervention period, underscoring their potential to enhance these aspects of physical function.
Accurately predicting joint torque using wearable sensors is crucial for designing assist-as-needed exoskeleton controllers to assist muscle-generated torque and ensure successful task performance. In this paper, we estimated ankle dorsiflexion/plantarflexion, knee flexion/extension, hip flexion/extension, and hip abduction/adduction torques from electromyography (EMG) and kinematics during daily activities using neuromusculoskeletal (NMS) models and long short-term memory (LSTM) networks. The joint torque ground truth for model calibrating and training was obtained through inverse dynamics of captured motion data. A cluster approach that grouped movements based on characteristic similarity was implemented, and its ability to improve the estimation accuracy of both NMS and LSTM models was evaluated. We compared torque estimation accuracy of NMS and LSTM models in three cases: Pooled, Individual, and Clustered models. Pooled models used data from all 10 movements to calibrate or train one model, Individual models used data from each individual movement, and Clustered models used data from each cluster. Individual, Clustered and Pooled LSTM models all had relatively high joint torque estimation accuracy. Individual and Clustered NMS models had similarly good estimation performance whereas the Pooled model may be too generic to satisfy all movement patterns. While the cluster approach improved the estimation accuracy in NMS models in some movements, it made relatively little difference in the LSTM neural networks, which already had high estimation accuracy. Our study provides practical implications for designing assist-as-needed exoskeleton controllers by offering guidelines for selecting the appropriate model for different scenarios, and has potential to enhance the functionality of wearable exoskeletons and improve rehabilitation and assistance for individuals with motor disorders.
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.
This study investigated the acute effects of compression garments (CG) on balance control in elite athletes. 15 male professional handball players were recruited. They had to stand as motionless as possible in a monopedal stance on a force plate with the eyes closed and on a wobble board with the eyes open, while wearing CG or not. Centre of foot pressure mean velocity and surface area were calculated. Statistics were first calculated with the data from the whole sample. A hierarchical cluster analysis was also performed in order to categorize the participants' behaviours into subgroups with similar characteristics. The whole group analysis showed that there were no significant effects attributed to CG. The clustering analysis identified two distinct and homogeneous subgroups of participants. Only athletes with the best balance abilities at baseline could benefit from CG wearing to improve their balance control. These athletes, who swayed less and were more sensitive to somatosensory manipulation due to CG wearing, seem to control balance by adopting a support-dependent preferred sensorimotor tactic. Our findings suggest that amongst high-level athletes, the ability to benefit from CG wearing to improve balance control seems to depend on participants' intrinsic balance skills and/or preferred sensorimotor tactics. Full text: https://rdcu.be/b7ote
International Journal of Exercise Science 13(1): 714-722, 2020. The purpose of this study was to compare the muscle activation of the scapula, leg, and trunk among the front squat (FS), overhead squat (OHS), back extension (BE) and plank (PL). Seven recreationally trained men (age: 28 ± 3.6 years, body mass: 92 ± 26.1 kg, height: 175 ± 5.3 cm, 3-RM front squat test: 125 ± 49.8 kg, 3-RM overhead squat test: 91 ± 15.5 kg) participated in this within-subject crossover design. Two isometric exercises (plank and Biering-Sorenson back extension) were also included for trunk musculature comparisons. Neuromuscular activitation of the vastus lateralis (VL), biceps femoris (BF), thoracic region of erector spinae (ES), middle trapezius (MT), rectus abdominis (RA), external oblique (EO), serratus anterior (SA), and anterior deltoid (AD). The neuromuscular activity of the FS and OHS were analyzed using a 2 X 3 (squat variation X intensity) repeated measures analysis of variance (ANOVA). Effects were further analyzed by Bonferroni corrected paired t-tests. Results showed that AD activity was significantly greater (p < .05) during the FS compared to OHS at 65 and 95% of the 3-RM, while MT activity was significantly greater (p < .05) during the OHS than the FS at 80 and 95% of the 3-RM. ES activity was significantly greater (p< .05) during both the FS and OHS compared to the BE, but PL elicited significantly greater EO and RA activity than both the FS and OHS. These findings reveal that the FS and OHS can help facilitate the activation of muscles supporting the shoulder complex, scapula and lower back.
Keeler, JM, Pohl, MB, Bergstrom, HC, Thomas, JM, and Abel, MG. The effect of tactical tasks and gear on muscle activation of SWAT officers. J Strength Cond Res XX(X): 000-000, 2019-Special Weapons and Tactics (SWAT) officers perform a variety of tactical operations while wearing tactical gear. Load carriage has been shown to alter muscle activation in the torso and is also associated with lower back pain, which is a prevalent musculoskeletal injury suffered by SWAT Officers. The purpose of this study was to quantify the effect of tactical gear on muscle activation of torso musculature while performing occupational tasks. Twenty male SWAT Officers (age: 34.7 ± 4.5 years; height: 1.79 ± 0.1 m; body mass: 91.5 ± 17.3 kg) performed 4 tasks (standing, rifle walk, sitting, and shield walk) with and without gear (mass of gear: 13.8 ± 1.9 kg). Mean electromyographic amplitude was evaluated bilaterally for the erector spinae, rectus abdominis, and external oblique muscles during the trials and expressed relative to maximal voluntary isometric contraction (MVIC). Addition of gear significantly increased erector spinae mean muscle activation during the rifle walk task (mean delta: +0.16%). However, no differences in muscle activation were identified for any other muscles between gear conditions (effect size ≤ 0.15). The shield walk produced the highest mean activation for each muscle during different tasks. The dynamic tasks yielded (0.24-4.18% MVIC) greater muscle activation levels than sitting and standing tasks. Despite minimal increases in muscle activation levels with the addition of gear, load carriage is known to increase the risk of acute and chronic injury. Collectively, these findings indicate that SWAT Officers should perform most skills without gear during tactical training to simulate task-specific movement patterns but reduce the risk of musculoskeletal injury.
Les patients présentant une pathologie rachidienne dégénérative témoignent généralement de douleurs ayant un retentissement sur leurs capacités locomotrices. L’évaluation préopératoire des individus repose actuellement sur la réalisation d’auto-questionnaire déclaratifs validés qui permettent d’approximer l’état fonctionnel. Aucun consensus sur l’analyse des résultats d’une chirurgie rachidienne n’est actuellement établi. Les capacités fonctionnelles réelles sont intéressantes pour étudier l’impact des pathologies rachidiennes. L’évaluation des capacités locomotrices et fonctionnelles de manière quantitative pourrait être utilisé afin d’améliorer la prise en charge des patients. L’objectif de cette thèse est d’utiliser l’évaluation des capacités locomotrices des patients comme marqueur des capacités fonctionnelles pour décrire une sémiologie quantifiée des patients candidats à une chirurgie du rachis.Matériels et méthodes :Mise en place du projet SPEED (Évaluation quantitative de la motricité avant et après une chirurgie du rachis chez les patients atteints de pathologie rachidienne dégénérative). Ce protocole prospectif a été mis en place en 2016 avec une période d’inclusion de 2 ans. Au total 40 patients ont été inclus dans cette étude. Les données présentées dans ce manuscrit correspondent aux études ancillaires de nos résultats. Cette thèse se compose de 4 articles principaux : évaluation quantitative clinique puis radiologique des patients, modélisation de l’équilibre sagittal permettant une quantification de l’équilibre sagittal dynamique, et méta-analyse sur la capacité discriminante de l’analyse quantifiée du mouvement au sujet du mouvement du tronc et du pelvis.Résultats :Premièrement, pour la partie clinique, nous trouvons un décalage important entre les limitations perçues et celles réelles des capacités de marche chez les patients atteints de canal lombaire étroit. L'évaluation directe de la vitesse de marche libre est plus pertinente que le périmètre de marche car elle est corrélée à l'état fonctionnel et est plus facile à mettre en œuvre dans la pratique.Deuxièmement, concernant l’analyse radiologique, nous trouvons une amélioration de l'équilibre sagittal et de la lordose lombaire après une chirurgie de décompression lombaire postérieure sans fusion. Cette amélioration est surtout retrouvée chez des patients qui présentent des troubles posturaux antalgiques liée à la sténose lombaire. Cette compensation antalgique est difficile à différencier des troubles statiques avec nos outils de mesure actuels.Troisièmement, concernant l’analyse du mouvement, nous avons réalisé la première étude montrant que les paramètres de mouvement 3D peuvent estimer correctement la « sagittal vertical axis » calculée sur l'imagerie. De plus, cette estimation pourrait être utilisé lors de l'analyse de la marche et nous pensons qu'un tel type d'analyse permettrait de mieux caractériser les déficiences des patients.Quatrièmement, concernant l’analyse quantifiée tronc/pelvis, nous confirmons que les patients lombalgiques présentent une coordination tronc/pelvis différente dans le plan transverse au cours de la marche. De plus, notre méta-analyse confirme et révèle cette différence significative en montrant une coordination plus en phase pour les patients lombalgiques par rapport aux sujets en bonne santé pendant la marche. La coordination entre ces mouvements est plus rigide en présence de lombalgie et refléterait les adaptations neuromusculaires nécessaires pour adopter un comportement de protection sans douleur pendant la marche.
Abstract Background Myotonic Dystrophy 1 (DM1) causes progressive myopathy of extremity muscles. DM1 may also affect muscles of the trunk. The aim of this study was to investigate fat infiltration and muscle size in trunk muscles in DM1 patients, and in an age and gender matched control group. Further, explore how fat infiltration and degree of atrophy in these muscles are associated with motor and respiratory function in DM1 patients. Method We measured fat infiltration and trunk muscle size by MRI in 20 patients with genetically confirmed classic form of DM1, and compared these cases with 20 healthy, age and gender matched controls. In the DM1 group, we investigated correlations between MRI findings and clinical measures of muscle strength, mobility and respiration. We used sum scores for fat infiltration and muscle size in trunk flexors and trunk extensors in the analysis of group differences and correlations. Results Significant differences between cases and controls were present for fat infiltration in trunk flexors (p = 0.001) and trunk extensors (p
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.
Background:
Weakness of trunk muscles is a common disorder in children with cerebral palsy (CP). They encounter decreased levels of endurance that can lead to diminished capacity of movement.
Objective:
To evaluate the effect of core stability training on the endurance of trunk muscles and gait parameters in children with hemiplegic CP.
Methods:
Thirty children with hemiplegic CP aged 10 to 12 years were randomly assigned to two groups of equal number; control group (A) and study group (B). Both groups underwent the same designed physical therapy program. Moreover, group B underwent core stability training 3 times/week for 8 weeks. Endurance time of trunk muscles and gait parameters were measured before and after the intervention using the trunk endurance tests and the Biodex gait trainer respectively.
Results:
Both groups showed pre- and post-test statistically significant improvements in the endurance time of trunk flexors and extensors and gait parameters but only group B showed significant improvement in the endurance time of lateral trunk muscles. There were post-treatment statistically significant differences between both groups in favor of group B regarding all measured variables.
Conclusion:
Addition of core stability exercises to the treatment program can effectively improve the endurance time of trunk muscles and gait in children with hemiplegic CP.
Nonspecific low back pain (LBP) is a common musculoskeletal problem that is intensified during physical activity. Patients with LBP have been reported to change their abdominal muscle activity during walking; however, the effects of pain intensity, disability level, and fear-avoidance belief on this relationship have not been evaluated. Thus, we compared abdominal muscle activity in patients with LBP and asymptomatic controls, and assessed the impact of pain intensity, disability level, and fear-avoidance belief.
Thirty patients with LBP divided into groups reporting low (LLBP) and high-pain intensity low back pain (HLBP), and 15 participants without LBP were recruited. LBP patients’ self-reported pain intensity, disability, and fear-avoidance belief were recorded. To examine abdominal muscle activity (rectus abdominis [RA], internal [IO], and external oblique [EO] muscles) during walking, all subjects walked at a self-selected speed. Abdominal muscle activity (RA, IO, and EO) was compared among groups (LLBP, HLBP, and controls) in different phases of walking (double support vs swing). Relationships between abdominal muscle activity and clinical measures (pain intensity, disability, fear-avoidance belief) were analyzed using partial correlation analysis.
Right IO muscle activity during walking was significantly decreased in LLBP and HLBP compared with controls in certain walking phase. Partial correlation coefficients showed significant correlations between fear-avoidance belief and right EO activity (r = .377, P < .05) and between disability index and left IO activity (r = .377, P < .05) in patients with LBP. No significant difference was found in abdominal muscle activity in walking between patients with LLBP and HLBP (P > .05).
This study demonstrated decreased IO muscle activity during certain walking phases in LLBP and HLBP compared with asymptomatic participants. Although altered IO muscle activity during walking was observed in patients with LBP, no changes were found with other abdominal muscles (EO, RA). Thus, these results provide useful information about abdominal muscle activity during walking in patients with LBP.
Functional connectivity patterns of the motor cortical representational area of single muscles have not been extensively mapped in humans, particularly for the axial musculature. Functional connectivity may provide a neural substrate for adaptation of muscle activity in axial muscles that have both voluntary and postural functions. The purpose of this study was to combine brain stimulation and neuroimaging to both map the cortical representation of the external oblique (EO) in primary motor cortex (M1) and supplementary motor area (SMA), and to establish the resting-state functional connectivity associated with this representation. Motor-evoked potentials were elicited from the EO muscle in stimulation locations encompassing M1 and SMA. The coordinates of locations with the largest motor-evoked potentials were confirmed with task-based fMRI imaging during EO activation. The M1 and SMA components of the EO representation demonstrated significantly different resting-state functional connectivity with other brain regions: the SMA representation of the EO muscle was significantly more connected to the putamen and cerebellum, and the M1 representation of the EO muscle was significantly more connected to somatosensory cortex and the superior parietal lobule. This study confirms the representation of a human axial muscle in M1 and SMA, and demonstrates for the first time that different parts of the cortical representation of a human axial muscle have resting-state functional connectivity with distinct brain regions. Future studies can use the brain regions of interest we have identified here to test the association between resting-state functional connectivity and control of the axial muscles.
Neurogenic intermittent claudication is a main symptom in lumbar spinal stenosis (LSS), and postural change is often observed during walking. This study aimed to identify the changes in posture and muscle activity in the trunk and legs during walking in patients with LSS by examining 6 patients who had undergone decompression surgery. None of them had significant paralysis. Gait analysis using Vicon motion capture system® with electromyographic recordings of the paravertebral muscles (PVM) and vastus lateralis muscle (VL) was performed preoperatively and 2 weeks postoperatively. Results showed that the thorax angle indicating the degree of trunk flexion after walking decreased significantly and the pelvic angle tended to decrease after surgery. However, there were no difference in the spine angle, which is a measure of the motion of the thoraco-lumbar spine among the evaluations. The knee angle increased significantly after surgery both at the beginning and at the end of walking, but the angles of the hip and ankle did not change significantly after surgery. Knee torques increased significantly after surgery both at the beginning and at the end of walking. The activity of the PVM decreased and that of the VL increased after surgery. The results indicate that patients with LSS walk in a forward-bending position without flexing the spine, which can be one of the neurologic symptoms. Increases in knee torque and VL activity seemed to reflect the increase of walking speed, and the decrease of PVM activity appeared to be caused by postural improvement after surgery.
Over the last two decades, exercise of the core muscles has gained major interest in professional sports. Research has focused on injury prevention and increasing athletic performance. We analyzed the guidelines for so-called functional strength training for back pain prevention and found that programs were similar to those for back pain rehabilitation; even the arguments were identical. Surprisingly, most exercise specifications have neither been tested for their effectiveness nor compared with the load specifications normally used for strength training. Analysis of the scientific literature on core stability exercises shows that adaptations in the central nervous system (voluntary activation of trunk muscles) have been used to justify exercise guidelines. Adaptations of morphological structures, important for the stability of the trunk and therefore the athlete’s health, have not been adequately addressed in experimental studies or in reviews. In this article, we explain why the guidelines created for back pain rehabilitation are insufficient for strength training in professional athletes. We critically analyze common concepts such as ‘selective activation’ and training on unstable surfaces.
Study Design
Controlled laboratory study, with a case-control, cross-sectional design.
Background
Individuals with low back pain have impaired activation of the multifidus during postural adjustments and increased activity of the erector spinae musculature during walking. However, it is unclear whether these alterations in muscle activity are evident during locomotion in individuals with a history of low back pain when they are between symptomatic episodes.
Objectives
To compare paraspinal muscle activity in young, healthy individuals and young individuals with a history of low back pain during walking turns.
Methods
Fourteen asymptomatic individuals with a history of low back pain and 14 controls performed 90° walking turns at both a self-selected speed and a fast speed. The duration and amplitude of activity in the deep fibers of the multifidus and the lumbar and thoracic longissimus were quantified using intramuscular electromyography.
Results
There was a significant speed-by-group interaction for the duration of multifidus activity (P = .013). Duration of activity increased from the self-selected speed to the fast locomotor speed in the controls, but decreased in the individuals with a history of low back pain (P = .003). Self-selected speed was the same in both groups (P = .719). There was a trend toward a significant association between group and the direction of change in the duration of deep multifidus activity (χ ² = 0.058). Duration of thoracic longissimus activity and amplitude of multifidus and thoracic longissimus activity increased similarly in both groups from the self-selected to the faster speed.
Conclusion
Even between symptomatic episodes, young individuals with a history of low back pain demonstrated altered recruitment of the deep fibers of the lumbar multifidus in response to changing locomotor speed during walking turns. J Orthop Sports Phys Ther 2016;46(5):365–374. Epub 21 Mar 2016. doi:10.2519/jospt.2016.6230
Activities of daily living include carrying objects using one hand. Carrying a load using one hand can alter the loading on the musculoskeletal system as well as the walking pattern. The objective of this pilot study was to quantify the ground reaction forces, electromyographic (EMG) activity of trunk muscles, and trunk motion during walking. Nine human volunteers with no symptoms of pain were recruited from the student and employee population of an academic institution. Data were recorded from 8 volunteer subjects. Participants were asked to walk at selfselected speed back and forth at their comfortable speed carrying loads varying from 0 to 25 pounds on right hand on a wooden walking platform for 30 steps/cycles. Motion data were recorded from T1, L1, L3, and S1 vertebrae at a sampling frequency of 120 Hz. Range of Motion (ROM), Correlation Dimension (CoD), and Approximate Entropy (ApEn) was computed using custom written MatLab programs. EMG data were recorded from six muscle groups bilaterally (right and left): Erector Spinae, Multifidus, Latissimus Dorsi, Internal Obliques, External Obliques and Rectus Abdominis at a frequency of 1200 Hz. Root mean square EMG values, Mean and Median Frequency of the EMG data were calculated to observe the effect of increasing load on muscle fatigue using custom developed MatLab program. Ground reaction force (GRF) data were collected using a force plate and the associated 1st peak force (Fz1), 2nd Peak force (Fz3) and minimum force (Fz2) between the two peak forces were calculated during gait cycle. The ROM values had a range from 2.6-3.2 deg. for Lumbar lateral bending (LB), 6.7-8.7 deg. for Thoracic LB. Approximate Entropy (ApEn) values ranged from 0.20-0.40 for Lumbar LB motion and 0.30-0.50 for Thoracic LB motion. Correlation Dimension (CoD) values ranged from 1.20-1.40 for lumbar LB and 1.20-1.30 for Thoracic LB. Normalized GRF increased during walking with increased load. Significance difference (P<0.05) were found for vGRF with increase in load. Motion and EMG data did not reveal any significant differences.
Typical gait analyses commonly define the trunk as a single rigid segment, which overlooks its inter-segmental motion. The current study examined the validity and reliability of a multi-segmented trunk marker set and the quantification of trunk motion during gait. A total of 10 young subjects were tested on two different days using identical procedures which incorporated a 22-marker set to define 7 trunk segments. Validity was evaluated by comparing results to a previous protocol. Reliability was assessed with the range of motion (ROM), coefficient of multiple correlation (CMC) and intraclass correlation coefficient (ICC). The multi-segmented trunk marker set was able to reveal different inter-segmental movement patterns. During gait, ROM reliability was approximately 92%, and within-day CMC displayed moderate to strong reliabilities while between-day CMC data had moderately weak to moderately strong associations of the multi-segmented angle waveform trajectories. Reliability of the peak angles, assessed by ICC ranged from poor to almost perfect. The findings provide trends that suggest the incorporation of a multi-segmented trunk marker set could add a useful assessment to gait analysis.
During gait, the trunk and neck are believed to play an important role in dissipating the transmission of forces from the ground to the head. This attenuation process is important to ensure head control is maintained. The aim of the current study was to assess the impact of externally restricting the motion of the trunk and/or neck segments on acceleration patterns of the upper body and head and related trunk muscle activity. Twelve healthy adults performed 3 walking trials on a flat, straight 65 m walkway, under four different bracing conditions: (1) Control-no brace, (2) Neck-braced, (3) Trunk-braced, and (4) Neck-trunk braced. 3D acceleration from the head, neck (C7) and lower trunk (L3) were collected as were muscle activity from trunk. Results revealed that, when the neck and/or trunk were singularly braced, an overall decrease in the ability of the trunk to attenuate gait related oscillations was observed which led to increases in the amplitude of vertical acceleration for all segments. However, when the trunk and neck were braced together, acceleration amplitude across all segments decreased in line with increased attenuation from the neck to the head. Bracing was also reflected by increased activity in erector spinae, decreased abdominal muscle activity and lower trunk muscle co-activation. Overall, it would appear that the neuromuscular system of young, healthy individuals was able to maintain a consistent pattern of head acceleration irrespective of the level of bracing and that priority was placed over the control of vertical head accelerations during these gait tasks.
Copyright © 2015, Journal of Neurophysiology.
This study aimed to investigate the effect of horse riding simulation (HRS) on balance and trunk muscle activation as well as to provide evidence of the therapeutic benefits of the exercise. Thirty elderly subjects were recruited from a medical care hospital and randomly divided into an experimental and a control group. The experimental group performed the HRS exercise for 20 min, 5 times a week, for 8 weeks, and conventional therapy was also provided as usual. The muscle activation and limits of stability (LOS) were measured. The LOS significantly increased in the HRS group (p < 0.05) but not in the control group (p > 0.05). The activation of all muscles significantly increased in the HRS group. However, in the control group, the muscle activations of the lateral low-back (external oblique and quadratus lumborum) and gluteus medius (GM) significantly decreased, and there was no significant difference in other muscles. After the intervention, the LOS and all muscle activations significantly increased in the HRS group compared with the control group. The results suggest that the HRS exercise is effective for reducing the overall risk of falling in the elderly. Thus, it is believed that horse riding exercise would help to increase dynamic stability and to prevent elderly people from falling.
Background
For the development of specialized training protocols for robot assisted gait training, it is important to understand how the use of exoskeletons alters locomotor task demands, and how the nature and magnitude of these changes depend on training parameters. Therefore, the present study assessed the combined effects of gait speed and body weight support (BWS) on muscle activity, and compared these between treadmill walking and walking in the Lokomat exoskeleton.
Methods
Ten healthy participants walked on a treadmill and in the Lokomat, with varying levels of BWS (0% and 50% of the participants’ body weight) and gait speed (0.8, 1.8, and 2.8 km/h), while temporal step characteristics and muscle activity from Erector Spinae, Gluteus Medius, Vastus Lateralis, Biceps Femoris, Gastrocnemius Medialis, and Tibialis Anterior muscles were recorded.
Results
The temporal structure of the stepping pattern was altered when participants walked in the Lokomat or when BWS was provided (i.e. the relative duration of the double support phase was reduced, and the single support phase prolonged), but these differences normalized as gait speed increased. Alternations in muscle activity were characterized by complex interactions between walking conditions and training parameters: Differences between treadmill walking and walking in the exoskeleton were most prominent at low gait speeds, and speed effects were attenuated when BWS was provided.
Conclusion
Walking in the Lokomat exoskeleton without movement guidance alters the temporal step regulation and the neuromuscular control of walking, although the nature and magnitude of these effects depend on complex interactions with gait speed and BWS. If normative neuromuscular control of gait is targeted during training, it is recommended that very low speeds and high levels of BWS should be avoided when possible.
Background:
Strengthening of core hip, trunk, and abdominal muscles has been utilized with injury prevention and low back pain and has the potential to improve athletic performance.
Hypothesis:
During a side-bridge, trunk and thigh muscles on the ipsilateral weightbearing side would produce greater activation than their counterparts on the contralateral nonweightbearing side.
Study design:
Descriptive laboratory study.
Methods:
Twelve females and 13 males participated. Electromyography (EMG) signals were gathered for 5 right-sided muscles (rectus abdominis [RA], external oblique [EO], longissimus thoracis [LT], lumbar multifidus [LM], and gluteus medius [GM]) during 3 repetitions of 4 side-bridging exercises (trunk-elevated side support [TESS], foot-elevated side support [FESS], clamshell, and rotational side-bridge [RSB]) performed bilaterally in random order using surface electrodes. EMG signals were normalized to peak activity in maximum voluntary isometric contraction (MVIC) trials and expressed as a percentage. Descriptive EMG data were calculated for EMG recruitment (% MVIC) and compared between right side up and right side down conditions and between exercises with 2-way repeated-measures analyses of variance at α = 0.05.
Results:
RSB created the most muscle activation in 3 of 4 recorded trunk muscles (RA, 43.9% MVIC; EO, 62.8 % MVIC; and LT, 41.3% MVIC). Activation of the GM exceeded 69% MVIC for TESS, FESS, and RSB. With the exception of the RA in RSB and LT in TESS, recruitment within muscles of the ipsilateral weightbearing trunk and thigh (% MVIC) was significantly greater than their counterparts on the nonweightbearing trunk and thigh for all muscles during the side-bridge exercise conditions.
Conclusion:
Muscle recruitment was greater within muscles of the ipsilateral weightbearing trunk and thigh for all examined muscles except RA during RSB and LT during TESS. Activation at or above 50% MVIC is needed for strengthening. Activation of the GM and EO meets these requirements.
Clinical relevance:
Side-bridge exercises appear to provide strengthening benefits to core hip, trunk, and abdominal muscles on the ipsilateral weightbearing side.
Efficient gait is compensate for a lack of exercise, but the wrong walking can cause disease that joints, muscles, brain and body structure(Scott & Winter, 1990). Also many researchers has been studied gait of positive mechanism using analytical methods kinetic, kinematic. This study is to identify nature of knee adduction moment, depending on different foot progression angle and the movement of rotation of pelvis and body. Health study subject conducted intended walking with three different angles. The subjects of this study classified three types of walking; walk erect, pigeon-toed walk and an out-toed gait. Ten university students of K without previous operation and disease record selected for this study. For accuracy of this study, three types of walking carried out five times with 3D image analysis and using analysis of ground reaction force to analyze nature of knee adduction moment and the movement of rotation of pelvis and body. Firstly, the HC(heel contact) section value of intended walk erect, pigeon-toed walk and an out-toed gait was not shown statistically significant difference but TO(toe off) section value was shown that the pigeon-toed walk statistically significant. The value of pigeon-toed walk was smallest knee adduction moment(p< 0.005). Secondly, X axis was the change of rotation movement body and pelvis when walk erect, pigeon-toed walk and an out-toed gait. Shown statistically Y axis was not shown statistically significant but Z axis statistically significant(p
The assessment of abdominal muscles has became popular in recent years because the study of "core muscles" is now considered a pivotal approach for a number of fields. The purpose of this study was to describe the innervation zone (IZ) locations and optimal electrode sites in two core muscles: the obliquus externus (OE) and the obliquus internus (OI) abdominis muscles. Twenty healthy male subjects were recruited and the IZ location was studied during a submaximal isometric contraction using multichannel surface EMG. The optimal electrode position for OI was found to be 2cm lower the most prominent point of the anterior superior iliac spine, just medial and superior to the inguinal ligament. The optimal electrode position for OE was found to be 14cm from the median line, lower the level of 1cm above umbilicus, parallel to the line extending from the most inferior point of the costal margin to the opposite pubic tubercle (almost 45° with respect to the median line). Findings showed that for OI and OE muscles it is possible to provide indications for a muscle belly area suited for proper positioning of at least an electrode pair.
Purpose: Most studies on barefoot and shod walking have so far focused on leg muscle activity. However, footwear might also have an impact on the back and neck. The aim of the present study was to compare back and neck muscle activity as well as kinematic gait parameters during barefoot walking, conventional shod walking and walking in flexible shoes, commercially designed with the intention to imitate barefoot walking.Methods: Thirty healthy subjects (16 male and 14 female, mean age 31.4 ± 12.8 years) walked at self-selected speed over an instrumented walkway mat, either barefoot, with their own casual shoes or with these flexible shoes. Muscle activity was measured by EMG from the lumbar iliocostalis muscle, the lumbar longissimus muscle, the lumbar multifidi muscles, the trapezius muscle (pars descendens), the neck extensor muscles and the sternocleidomastoideus muscle.Results: The results indicated that back and neck muscle activity was slightly lower when wearing conventional footwear as opposed to walking barefoot or in the flexible shoe. Both the conventional and the flexible shoe, in contrast, significantly altered the kinematic gait parameters.Conclusions: Back and neck muscle activity was slightly influenced by footwear. The relevance of these findings should be investigated in the long term by longitudinal studies with healthy subjects as well as with patients suffering from lower back and neck pain.
Objective: To establish any changes up to the second postoperative month in pain, disability, performance, kinesiophobia, and lower extremity motor coordination of patients operated on for lumbar disc hernia. Methods: Forty-five patients with lumbar disc hernia were included in the study preoperatively, and were followed up until the second postoperative month. Pain and disability, walking and stair-climbing performances, and kinesiophobia were measured; and motor coordination tests were practiced with the Lower Extremity MOtor COordination Test (LEMOCOT). Results: The worst scores of pain, disability, performance, kinesiophobia, and LEMOCOT measurements were in the preoperative period; while the best ones were observed in the 2 months following the surgery. Conclusion: The measurements of pain, disability, performance, kinesiophobia, and lower extremity coordination usually performed in the cases operated on with a diagnosis of lumbar disc hernia are significantly affected from the initial period until the second postoperative month.
Purpose: We investigated the trunk muscles, activities for stabilizing the spine against load by arm movement. [Subjects] Eight male subjects participated in this study. Methods: Subjects performed 1) a pushing forward task (load perpendicular to the trunk) and 2) a pushing downward task (load parallel to the trunk) at different load magnitudes with isometric arm extension. Electromyography (EMG) of rectus abdominis (RA), oblique internus abdominis (OI), oblique externus abdominis (OE), lumbar mutifidus (LM), and longissimus thoracis (LT) were recorded with surface electrodes. Results: Activity of RA, OE and OI increased with load magnitude in both tasks. RA was influenced by load direction. The activity of RA in the downward pushing task was larger than in the forward pushing task. Activities of LM and LT were influenced by load magnitude, but these muscles activities were low. Conclusion: The RA muscle is the only muscle influenced by direction of load to the trunk.
High plantar pressures have been associated with foot ulceration in people with diabetes, who can experience loss of protective sensation due to peripheral neuropathy. Therefore, characterization of elevated plantar pressure distributions can provide a means of identifying diabetic patients at potential risk of foot ulceration. Plantar pressure distribution classification can also be used to determine suitable preventive interventions, such as the provision of an appropriately designed insole. In the past, emphasis has primarily been placed on the identification of individual focal areas of elevated pressure. The goal of this study was to utilize k-means clustering analysis to identify typical regional peak plantar pressure distributions in a group of 819 diabetic feet. The number of clusters was varied from 2 to 10 to examine the effect on the differentiation and classification of regional peak plantar pressure distributions. As the number of groups increased, so too did the specificity of their pressure distributions: starting with overall low or overall high peak pressure groups and extending to clusters exhibiting several focal peak pressures in different regions of the foot. However, as the number of clusters increased, the ability to accurately classify a given regional peak plantar pressure distribution decreased. The balance between these opposing constraints can be adjusted when assessing patients with feet that are potentially "at risk" or while prescribing footwear to reduce high regional pressures. This analysis provides an understanding of the variability of the regional peak plantar pressure distributions seen within the diabetic population and serves as a guide for the preemptive assessment and prevention of diabetic foot ulcers.
We investigated upper-body (ie, trunk) angular kinematics (motions) during gait, stair climbing and descending, and rising from a chair in two reference frames--relative to the pelvis and to room coordinates. Bilateral kinematic data were collected from 11 healthy subjects (6 female, 5 male), who were 27 to 88 years of age (mean = 58.9, SD = 17.9). During stair climbing, maximum trunk flexion relative to the room was at least double that during stair descending and gait. Arising from a chair required the most trunk flexion/extension range of motion (ROM) but the least abduction/adduction and medial/lateral (internal/external) rotation. Trunk ROM during gait was small (mean less than or equal to 12 degrees) and consistent with previous literature. Trunk range of motion relative to the room during stair climbing and descending was greater than trunk ROM during gait in all planes. The pelvis and trunk rotate in the transverse plane in greater synchrony during stair descending (mean = 8.1 degrees, SD = 5.6 degrees) than during gait (mean = 12.0 degrees, SD = 4.2 degrees). For all activities, trunk frontal and sagittal ROM relative to the pelvis was greater than that relative to the room coordinates. This finding suggests that trunk/pelvis coordination may be used to reduce potentially destabilizing anti-gravity trunk motions during daily activities. We conclude that upper-body kinematics relative to both pelvis and gravity during daily activities are important to locomotor control and should be considered in future studies of patients with locomotor disabilities.
A descriptive study of the biomechanical variables of the walking patterns of the fit and healthy elderly compared with those of young adults revealed several significant differences. The walking patterns of 15 elderly subjects, selected for their active life style and screened for any gait- or balance-related pathological conditions, were analyzed. Kinematic and kinetic data for a minimum of 10 repeat walking trials were collected using a video digitizing system and a force platform. Basic kinematic analyses and an inverse dynamics model yielded data based on the following variables: temporal and cadence measures, heal and toe trajectories, joint kinematics, joint moments of force, and joint mechanical power generation and absorption. Significant differences between these elderly subjects and a database of young adults revealed the following: the same cadence but a shorter step length, an increased double-support stance period, decreased push-off power, a more flat-footed landing, and a reduction in their "index of dynamic balance." All of these differences, except reduction in index of dynamic balance, indicate adaptation by the elderly toward a safer, more stable gait pattern. The reduction in index of dynamic balance suggests deterioration in the efficiency of the balance control system during gait. Because of these significant differences attributable to age alone, it is apparent that a separate gait database is needed in order to pinpoint falling disorders of the elderly.
A descriptive study of the biomechanical variables of the walking patterns of the fit and healthy elderly compared with those of young adults revealed several significant differences. The walking patterns of 15 elderly subjects, selected for their active life style and screened for any gait- or balance-related pathological conditions, were analyzed. Kinematic and kinetic data for a minimum of 10 repeat walking trials were collected using a video digitizing system and a force platform. Basic kinematic analyses and an inverse dynamics model yielded data based on the following variables: temporal and cadence measures, heal and toe trajectories, joint kinematics, joint moments of force, and joint mechanical power generation and absorption. Significant differences between these elderly subjects and a database of young adults revealed the following: the same cadence but a shorter step length, an increased double-support stance period, decreased push-off power, a more flat-footed landing, and a reduction in their “index of dynamic balance.” All of these differences, except reduction in index of dynamic balance, indicate adaptation by the elderly toward a safer, more stable gait pattern. The reduction in index of dynamic balance suggests deterioration in the efficiency of the balance control system during gait. Because of these significant differences attributable to age alone, it is apparent that a separate gait database is needed in order to pinpoint falling disorders of the elderly.
The Ward and Hook (1963) hierarchical grouping program is a frequently used method to cluster persons into groups. Because of a deficiency in the procedure, the groupings are somewhat less than optimal. In order to meet this deficiency, a two-part procedure was developed to be used in conjunction with the Ward and Hook program for a more optimal grouping of subjects. The first part of the procedure checks the assignments of the subjects to the groups and removes inappropriately classified subjects. The second part confirms the reassignments of the subjects to their groups. Specifics regarding the application of the two-part procedure are discussed.
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.
Studies on the proactive control of gait have shown that proximal (hip/trunk) muscles are the primary contributors to balance control, while studies on reactive balance control during perturbed gait, examining only activity in distal (leg/thigh) muscles, have shown that these muscles are important in compensating for a gait disturbance. This study tested the hypothesis that proximal muscles are also primary contributors to reactive balance control during perturbed gait. Thirty-three young adults participated in a study in which an anterior slip was simulated at heel strike by the forward displacement of a force plate on which they walked. Surface electromyographic data were recorded from bilateral leg, thigh, hip and trunk muscles. Kinematic data were collected on joint angle changes in response to the perturbation. The results did not support the hypothesis that the proximal muscles contribute significantly to balance control during perturbed gait. The proximal muscles did not demonstrate more consistent activation, earlier onset latency, longer burst duration or larger burst magnitude than distal muscles. Moreover, although proximal postural activity was often present in the first slip trial, it tended to adapt away in later trials. By contrast, the typical postural responses exhibited by young adults consisted of an early (90-140 ms), high-magnitude (4-9 times muscle activity during normal walking) and relatively long duration (70-200 ms) activation of bilateral anterior leg muscles as well as the anterior and posterior thigh muscles. Thus, postural activity from bilateral leg and thigh muscles and the coordination between the two lower extremities were the key to reactive balance control and were sufficient for regaining balance within one gait cycle. The adaptive attenuation of proximal postural activity over repeated trials suggests that the nervous system overcompensates for a novel balance threat in the first slip trial and fine-tunes its responses with experience.
The ability of surface electrodes to accurately detect the activity of a particular muscle relies not only on their being placed over the muscle but also on their position in relation to muscle fibre orientation. For optimal pick-up of electromyographic (EMG) signals, surface electrodes are best aligned in parallel with the fibre orientation of the underlying muscle. This study aimed to measure muscle fibre orientation and other parameters of muscle morphology of the abdominal muscles in relation to palpable bony landmarks. Thirty-seven embalmed cadavers (19 males and 18 females) were examined. Results showed that the fibres of obliquus externus abdominis were about 4 degrees more vertical than the lower edge of the eighth rib. Below the rib cage, the muscle fibres of obliquus externus abdominis were approximately 5 degrees closer to vertical than a reference line between the most inferior point of the costal margin and the contralateral pubic tubercle. In the anterolateral abdominal wall area below the anterior superior iliac spine (ASIS), the obliquus internus abdominis was superficial being covered only by the aponeurosis of obliquus externus abdominis. At the level of ASIS, the muscle fibres of obliquus internus abdominis were almost horizontally orientated but at 2 cm below ASIS were aligned about 6 degrees inferomedially to the horizontal. The muscle fibres of upper rectus abdominis were 2 degrees inferolateral to the midline while the lower rectus abdominis muscle fibres deviated inferomedially from the midline by about 8 degrees. The appropriate surface electrode placements which follows the muscle fibre orientation of the obliquus externus abdominis, obliquus internus abdominis and rectus abdominis have been suggested.
The weight of the upper part of the trunk is partially transmitted to the pelvis via the vertebral column. If the muscle walls around the abdominal cavity are contracted, a high pressure can be generated within the cavity (greater than 200 mmHg). The abdominal space can them transmit part of weight to, e.g., the upper part of the body, Intra-abdominal pressure recordings have been performed during locomotion and other natural movements with intragastric pressure recordings. With each step, there is a phasic variation in pressure, with its peak coinciding with that of the peak vertical force exerted by the leg against the ground. The peak values increase progressively with the speed of walking/running up to a mean of 38 mmHg and with trough values of 16 mmHg. The phasic variations with each step is due to a phasic activation of the abdominal muscles, with an EMG activity starting 50 ms or more before foot contact. If an extra load is put on the back, the posture changes and at the highest speed of running the pressure values are significantly higher than without this additional load. After a jump down from a moderate height of 0.4 m, the average increase is 89 mmHg and can often exceed 100 mmHg. These pressure changes are large and will presumably act to unload the spine under the prevailing biomechanical conditions and, in addition, there will no doubt be an effect on the circulatory system.
This study focused on the electromyographic activity of the trunk musculature, given the well-documented link between occupational twisting and the increased incidence of low back pain. Ten men and 15 women volunteered for this study, in which several aspects of muscle activity were examined. The first aspect assessed the myoelectric relationships during isometric exertions. There was great variability in this relationship between muscles and between subjects. Further, the myoelectric activity levels (normalized to maximal electrical activity) obtained from nontwist activities were not maximal despite maximal efforts to generate axial torque (e.g., rectus abdominis, maximum voluntary contraction; 22% external oblique, 52%; internal oblique, 55%; latissimus dorsi, 74%; upper erector spinae [T9], 61%; lower erector spinae [L3], 33%). In the second aspect of the study, muscle activity was examined during dynamic axial twist trials conducted at a velocity of 30 and 60 degrees/s. The latissimus dorsi and external oblique appeared to be strongly involved in the generation of axial torque throughout the twist range and activity in the upper erector spinae displayed a strong link with axial torque and direction of twist, even though they have no mechanical potential to contribute axial torque, suggesting a stabilization role. The third aspect of the study was comprised of the formulation of a model consisting of a three-dimensional pelvis, rib cage, and lumbar vertebrae and driven from kinematic measures of axial twist and muscle electromyograms. The relatively low levels of normalized myoelectric activity during maximal twisting efforts coupled with large levels of agonist-antagonist cocontraction caused the model to severely underpredict measured torques (e.g., 14 Nm predicted for 91 Nm measured). Such dominant coactivity suggests that stabilization of the joints during twisting is far more important to the lumbar spine than production of large levels of axial torque.
The ensemble electromyogram (EMG) patterns associated with different walking cadences were examined in 11 normal subjects. Five muscle groups were studied: the rectus femoris, vastus lateralis, lateral hamstring, tibialis anterior and soleus muscles of the right lower extremity. The myoelectric signals were telemetered, full-wave rectified and smoothed. Subjects walked at cadences of 115, 95 and 75 steps/min. Footswitches indicated the different phases of the stride. Six or more strides per subject were averaged for each cadence. Cadence-related changes in (1) mean EMG amplitude during stance, and during swing, and (2) the shape of the EMG patterns, were analyzed. One-way repeated-measures analyses of variance on the mean EMG amplitude in stance and in swing revealed significant changes with cadence (P less than 0.05) in all muscles examined. The magnitude of these changes could be related to the mechanical function of the muscles involved. The shape of the EMG patterns generally remained similar at the different cadences. The timing of EMG activity was closely related to the normalized stride time and remained invariant at different cadences.
The EMG patterns for 16 muscles involved in human walking are reported along with stride-to-stride and inter-subject variability measures. These profiles and measures were developed for basic researchers and clinical investigators as a baseline reference of motor patterns and for use in the diagnosis of gait pathologies. Evident from a comparison of these patterns were some fundamental aspects of the neuromuscular control and the mechanical demands of walking. These comparisons can be summarized as follows: (1) The distal support muscles (soleus, tibialis anterior, gastrocnemii) are the most active muscles, the more proximal muscles are least active. (2) The least variable EMG patterns, as quantified by the normalized inter-subject variability measures, are seen in the most distal single joint muscles, the most variable are the more proximal muscles. The EMGs of the biarticulate muscles, both proximal and distal, exhibit higher variability than the EMGs of the single joint muscles. (3) The detailed patterns and levels of EMG activity demonstrate the different mechanical tasks of each muscle over the gait cycle.
Considerable inter-individual variations in the fibre direction angles of the iliocostalis lumborum, longissimus and multifidus were observed, thus bringing the applicability of a two dimensional fixed angle grid system for fibre direction determination into question. However, the angulation of the fibres of the multifidus and iliocostalis lumborum were found to be easily identifiable by the use of three surface anatomical landmarks: the caudal tip of the superior iliac spine, the lateral border of the iliocostalis at the twelfth rib and the L1-L2 interspinous space. No reliable index was found for the longissimus. Suggested electrode placement sites for the electromyographic study of the iliocostalis lumborum and the multifidus are at the levels of the L2-L3 and the L4-L5 interspinous spaces respectively.
The mechanisms of adaptation of the trunk to changed mechanical conditions were studied during locomotion in man. The myoelectrical (EMG) activity in lumbar back muscles and the movements of the trunk were recorded in nine healthy subjects during walking and running on a motor-driven treadmill. Two different types of voluntary modifications of the movement pattern were used: (1) The trunk was kept in an extreme forward or backward tilted position. In both these situations the basic EMG pattern with two periods of activity per stride cycle was maintained during walking, whereas a major shift relative to the stride cycle (25% of the stride cycle duration) occurred in running with the trunk tilted backwards. The synchrony of the back muscle activation at both sides increased when locomotion was performed with the trunk tilted forwards. The relative duration of the EMG bursts was similar to normal locomotion and corresponded to 15-26% of the stride cycle duration in walking and 23-37% in running. (2) In the other type of modification the subjects were instructed to exaggerate the angular trunk movements either in the sagittal or in the frontal plane. The basic EMG pattern and phase relationships remained in most cases unchanged. One exception was running with exaggerated lateral movements, in which only one period of back muscle activity per stride cycle was observed. The relative duration of the bursts was longer in trials with exaggerated trunk movements as compared to normal locomotion. In walking and running with the trunk tilted forwards or backwards the lumbar back muscles were not always involved as prime movers of the trunk. This was in contrast to the more dynamic situations, in which the back muscle activity appeared to be directly involved in braking and reversing the exaggerated trunk movements.
To identify the degree of difference between treadmill and floor walking, kinematic, electromyographic (EMG), and heart rate measurements were recorded in seven normal female subjects during walking at three speeds on the treadmill and on the floor. During treadmill walking, subjects tended to use a faster cadence and shorter stride length than during floor walking. In addition the displacements of the head, hip, and ankle in the sagittal plane showed statistically significant differences between floor and treadmill walking. Average EMG activity was usually greater on the treadmill than on the floor; however, this difference was only significant for the quadriceps. Heart rate was significantly higher during fast treadmill walking than floor walking. In general, treadmill walking was not found to differ markedly from floor walking in kinematic measurements or EMG patterns.
The myoelectric activity of the mm. multifidi and the mm. iliocostales lumborum of six subjects was recorded during walking. The subjects walked on a treadmill as well as on a fixed walkway. On the treadmill, recordings were made at two different speeds and with a varying loading of the spine. There was almost no difference in myoelectric activity time between the treadmill and the fixed walkway. Related to unloaded walking, both the multifidi and the iliocostales showed an increase in activity time when the subjects carried a load of 5 kg in front of the trunk and a decrease of activity time with a load of 5 kg on the back. A load on the lateral aspect of the body shortened the muscle activity time of the multifidi on the homolateral side. In three subjects the same pattern was found for the iliocostales, but in the other three subjects there was no activity registered at all. On the side contralateral to the load, the multifidi showed no increase of activity time while the iliocostales muscles demonstrated an increase. It is concluded that during walking the iliocostalis muscle has a more important function in lateral bending than the multifidus. It was remarkable that the multifidi muscles of the left side were active for longer periods than were those of the right side in all situations except during lateral loading.
The effect of four amplitude normalization methods on intersubject variability of electromyographic (EMG) profiles in normal gait was examined. Bipolar silver/silver chloride surface electrodes were applied to the rectus femoris, vastus lateralis, biceps femoris, tibialis anterior, and soleus muscles of the right lower extremity, in 11 healthy subjects. The myoelectric signals were telemetered via an FM multichannel biotelemetry system, full-wave rectified and low-pass filtered, then A/D converted together with the footswitch signal. Within-subject ensemble-average patterns were generated from the linear envelope EMG of at least six strides for each subject. Each subject's ensemble average was then normalized to the following: (a) the average EMG over three 50% isometric maximum voluntary contractions (MVC), (b) the EMG per unit isometric moment of force, (c) the peak of the subject ensemble average, (d) the mean of the subject ensemble average. Intersubject variability was quantified for each of the normalization methods by the coefficient of variation (CV). The normalization to either the peak ensemble or the mean ensemble drastically reduced intersubject variability, by 12%-73%. In contrast, normalization to the average EMG during 50% MVC or to the EMG per unit moment increased intersubject variability. It was concluded that the reduction of intersubject variability by appropriate amplitude normalization is possible, thereby increasing the sensitivity of surface EMG as a diagnostic tool in gait analysis.
Kinematics and electromyographic (EMG) activity were recorded in seven normal women during walking at slow, free, and fast speeds. Speed-related differences were found in the stride dimensions, temporal components, and most of the simultaneous displacement patterns of body segments measured. For most of the muscles tested, the amplitude of normalized EMG activity decreased as walking speed decreased. The findings emphasize the importance of accounting for the effect of speed itself on measurements of gait.
Trunk movements in the frontal and sagittal planes were studied in 10 healthy males (18-35 yrs) during normal walking (1.0-2.5 m/s) and running (2.0-6.0 m/s) on a treadmill. Movements were recorded with a Selspot optoelectronic system. Directions, amplitudes and phase relationships to the stride cycle (defined by the leg movements) were analyzed for both linear and angular displacements. During one stride cycle the trunk displayed two oscillations in the vertical (mean net amplitude 2.5-9.5 cm) and horizontal, forward-backward directions (mean net amplitude 0.5-3 cm) and one oscillation in the lateral, side to side direction (mean net amplitude 2-6 cm). The magnitude and timing of the various oscillations varied in a different way with speed and mode of progression. Differences in amplitudes and timing of the movements at separate levels along the spine gave rise to angular oscillations with a similar periodicity as the linear displacements in both planes studied. The net angular trunk tilting in the frontal plane increased with speed from 3-10 degrees. The net forward-backward trunk inclination showed a small increase with speed up to 5 degrees in fast running. The mean forward inclination of the trunk increased from 6 degrees to about 13 degrees with speed. Peak inclination to one side occurred during the support phase of the leg on the same side. Peak forward inclination was reached at the initiation of the support phase in walking, whereas in running the peak inclination was in the opposite direction at this point. The adaptations of trunk movements to speed and mode of progression could be related to changing mechanical conditions and different demands on equilibrium control due to e.g. changes in support phase duration and leg movements.
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.
This report presents a selective overview of the cluster analysis literature and its potential uses in neuropsychology. In addition, an actual problem involving data from the Florida Longitudinal Project is presented to provide a practical example of many of the processes and problems involved in cluster analytic techniques. It is hoped that the reader will gain a theoretical and practical understanding of such methods and their potential usefulness in neuropsychology and other related areas.
The population distribution of the electromyographic patterns from several muscles in 25 normal subjects walking at free speed
was investigated. The utility and sufficiency of Karhunen-Loeve expansions for reducing the dimension of electromyographic
patterns was demonstrated. Cluster analysis was used to separate the constituent patterns into major groups.
Variability and bilateral symmetry of EMG gait-cycle profiles were studied in parkinsonian and healthy elderly subjects in the gastrocnemius, tibialis anterior, and vastus lateralis muscles. Components reflecting shape and timing were defined by the magnitude and phase of the cross-correlation function between individual stride profiles and the latency corrected ensemble average (LCEA) (variability), and between bilateral LCEAs (symmetry). Statistical significance was set at a confidence level of 0.01 reflecting a Bonferroni adjustment due to multiple measures. Parkinsonian gait was significantly different from the healthy elderly in several measures: increased shape variability and asymmetry in the gastrocnemius and tibialis anterior muscles, and reduced timing variability in the gastrocnemius. A portion of the parkinsonian group participated in a 3 week therapy program where they walked to rhythmic auditory stimulation. Gait parameters shifted toward healthy elderly values in each measure where population differences were found. Significant changes were observed in decreased tibialis anterior shape variability and asymmetry, and gastrocnemius shape variability. Strong trends were also observed in increased gastrocnemius timing variability and reduced bilateral asymmetry. In addition to the expected decreased in variability and asymmetry of healthy elderly, increased timing variability in the gastrocnemius was associated with a more normal gait, possibly reflecting feedback adaptability of muscle activity which may be useful in generating stable locomotion.
Physical therapists are among the most common users of electromyography as a method for understanding function and dysfunction of the neuromuscular system. However, there is no collection of references or a source that provides an overview or synthesis of information that serves to guide either the user or the consumer of electromyography and the data derived. Thus, the purpose of this article is to present a guide, accompanied by an inclusive reference list, for the use and interpretation of kinesiologic electromyographic data. The guide is divided into 4 major sections: collecting, managing, normalizing, and analyzing kinesiologic electromyographic data. In the first of these sections, the issues affecting data collection with both indwelling and surface electrodes are discussed. In the second section, data management through alternative forms of data processing is addressed. In the third section, various reasons and procedures for data normalization are discussed. The last section reviews qualitative descriptors once used as the only means of analyzing data, then focuses on more quantitative procedures that predominate today. The guide is intended as a tool for students, educators, clinicians, and beginning researchers who use and interpret kinesiologic electromyographic data. Modifications will likely be needed as alternative forms of collecting, managing, normalizing, and analyzing electromyographic data are proposed, used in various settings, and reported in the literature.
Human locomotion is a phenomenon of the most extraordinary complexity in which so great are the multitude of individual motions occurring simultaneously in the three planes of space that analysis is difficult without some unifying principle. The adoption of the concept that fundamentally locomotion is the translation of the center of gravity through space along a pathway requiring the least expenditure of energy supplies the necessary unifying principle which permits of qualitative analysis in terms of the essential determinants of gait. The six major determinants are pelvic rotation, pelvic tilt, knee and hip flexion, knee and ankle interaction, and lateral pelvic displacement. The serial observations of irregularities in these determinants provides insight into individual variation and a dynamic assessment of pathological gait. Pathological gait may be viewed as an attempt to preserve as low a level of energy consumption as possible by exaggerations of the motions at unaffected levels. Compensation is reasonably effective with the loss of one determinant of which that at the knee is the most costly. Loss of two determinants makes effective compensation impossible and the cost of locomotion in terms of energy is increased threefold with an inevitable drain upon the body economy.
A technique for automatically clustering linear envelopes of EMGs (electromyograms) during gait has been developed. It uses a temporal feature representation and a maximum peak matching scheme. This technique provides a viable way to define compact and meaningful EMG waveform features. The envelope matching is performed by dynamic programming, providing qualitatively the largest number of matched peaks and quantitatively a minimum distance measurement. The resulting averaged EMG profiles have low statistical variation and can serve as templates for EMG comparison and further classification.
Representing and clustering electromyographic gait patterns with multivariate techniques Components of EMG symmetry and variability in parkinsonian and healthy elderly gait
- R Shiavi
- P Griffen
- Ra Miller
- Mh Thaut
- Gc Mcintosh
- Rice
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Electromyographic patterns in normal adult locomotion In: Smidt GL, editor. Gait in rehabilitation
- R S G Shiavi
- P J White
- Mcnair
Shiavi R. Electromyographic patterns in normal adult locomotion. In: Smidt GL, editor. Gait in rehabilitation. New York: Churchill Livingstone; 1990. p. 97–119. 184 S.G. White, P.J. McNair / Clinical Biomechanics 17 (2002) 177–184
Gait analysis: normal and pathological function. New Jersey: Thorofare, SLACK Inc.; 1992. p
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Perry J. In: Gait analysis: normal and pathological function. New Jersey: Thorofare, SLACK Inc.; 1992. p. 136–7.
Electromyographic patterns in normal adult locomo-tion Gait in rehabilitation
- R Shiavi
Shiavi R. Electromyographic patterns in normal adult locomo-tion. In: Smidt GL, editor. Gait in rehabilitation. New York: Churchill Livingstone; 1990. p. 97–119.
Muscle fibre direction of Longissimus, Iliocostalis and Multifidus: landmark-derived reference lines
- DeFoa
Electromyographic patterns in normal adult locomotion
- Shiavi