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Muscular activity in treadmill and overground running
Abstract
It still remains unclear whether muscular activity on the treadmill (T) differs compared to overground (O) running. The purpose of this study was therefore to examine possible differences in muscular activation between T and O. 14 healthy runners were analyzed in a neutral running shoe at 12 km-h(-1) on a treadmill and in a field test. Muscular activity (EMG) of the tibialis anterior, peroneus longus, and soleus were measured. Time and amplitude quantities were assessed during the gait cycle. The EMG of the peroneus longus exhibited a later onset, a later maximum and shorter total time of activation (p < 0.05) in O. The soleus showed a higher amplitudes in O during the push-off phase (p < 0.05). Altered peroneus longus activity may indicate its role as an ankle stabilizer and demonstrates a compensatory response due to changing mechanical conditions. Weaker amplitudes of the soleus in the push-off during T suggest adaptation to the movement of the treadmill belt, and/or changes in load receptor input. Differences in muscle activity between T and O running must thus be taken into consideration in studies of neuromuscular control of movement.
... However, still this is debated that what neuromuscular changes will created in result of biomechanics alterations on the treadmill (25). Hong et al. (2012) and Baur et al. (2007) reported that the maximum plantar pressure is reduced while running on the treadmill in comparison to other surfaces (5,4). Though, if we accept the biomechanical differences between treadmill and overground running conditions, then we should expect changes in muscles activation. ...
... However, still this is debated that what neuromuscular changes will created in result of biomechanics alterations on the treadmill (25). Hong et al. (2012) and Baur et al. (2007) reported that the maximum plantar pressure is reduced while running on the treadmill in comparison to other surfaces (5,4). Though, if we accept the biomechanical differences between treadmill and overground running conditions, then we should expect changes in muscles activation. ...
... However, still this is debated that what neuromuscular changes will created in result of biomechanical changes on the treadmill (24). Results of Hong et al. (2012) and Baur et al (2007) showed that the maximum pressure of foot and the maximum force of foot plantar are reduced while running on the treadmill in comparison to other surfaces (5,4). ...
The aim of present study was to compare electromyography activity of selected leg-dominant lower limb muscles during stance phase of running on treadmill and overground. Fourteen male students ran at 3.3 m/s in both treadmill and overground conditions. Electromyography activity of some selected lower limb muscle was recorded during initial 50% and terminal 50% of stance phase. Paired t-test was employed for data analyses. The results showed a significant difference in total activity of selected lower limb muscles between treadmill and overground running conditions (P<0.05). Rectus femoris, vastus medialis, vastus lateralis, and biceps femoris activation during overground running were found significantly higher than running on the treadmill in initial 50% stance phase (P<0.05). No significant electromyography change was observed for selected muscles during terminal 50% of stance phase in both treadmill and overground conditions (P>0.05). It was concluded that treadmills running condition may be possibly useful in designing specific training programs that are aimed to control or reduce lower extremity muscles activity. According to the results of this study, treadmills running condition caused lower muscle activity consequently, may increase biomechanical efficiency or used in clinical setting.
... Running speeds ranged from 9.4 km/h [48] to 23.0 km/h [49] and were not specified in four studies. Similarly, the time between the MT and overground condition varied between 1 min [50] to 8 days [19,51] and was not specified in 16 studies. Finally, different approaches were used to familiarize the participants with MT running before data collection. ...
... It is often believed that MT running requires less propulsion as the MT moves the legs below the body, while in overground running the body needs to move over the legs. It has for example been suggested that whilst an explicit pushoff is required in overground running, the leg only needs to be lifted at the end of stance in MT running, resulting in reduced soleus activity in MT running [51]. However, the evidence for this is conflicting, with one study reporting no significant difference in soleus muscle activity [69], one study reporting higher and lower activity in the weight acceptance and push-off phase respectively [51], and two other studies reporting significantly lower activity in MT running [50,61]. ...
... It has for example been suggested that whilst an explicit pushoff is required in overground running, the leg only needs to be lifted at the end of stance in MT running, resulting in reduced soleus activity in MT running [51]. However, the evidence for this is conflicting, with one study reporting no significant difference in soleus muscle activity [69], one study reporting higher and lower activity in the weight acceptance and push-off phase respectively [51], and two other studies reporting significantly lower activity in MT running [50,61]. Similarly, it has been suggested that the hamstrings are used to a greater extent in overground than MT running to produce propulsive forces [87]. ...
Background
Treadmills are often used in research, clinical practice, and training. Biomechanical investigations comparing treadmill and overground running report inconsistent findings.
Objective
This study aimed at comparing biomechanical outcomes between motorized treadmill and overground running.
Methods
Four databases were searched until June 2019. Crossover design studies comparing lower limb biomechanics during non-inclined, non-cushioned, quasi-constant-velocity motorized treadmill running with overground running in healthy humans (18–65 years) and written in English were included. Meta-analyses and meta-regressions were performed where possible.
Results
33 studies (n = 494 participants) were included. Most outcomes did not differ between running conditions. However, during treadmill running, sagittal foot–ground angle at footstrike (mean difference (MD) − 9.8° [95% confidence interval: − 13.1 to − 6.6]; low GRADE evidence), knee flexion range of motion from footstrike to peak during stance (MD 6.3° [4.5 to 8.2]; low), vertical displacement center of mass/pelvis (MD − 1.5 cm [− 2.7 to − 0.8]; low), and peak propulsive force (MD − 0.04 body weights [− 0.06 to − 0.02]; very low) were lower, while contact time (MD 5.0 ms [0.5 to 9.5]; low), knee flexion at footstrike (MD − 2.3° [− 3.6 to − 1.1]; low), and ankle sagittal plane internal joint moment (MD − 0.4 Nm/kg [− 0.7 to − 0.2]; low) were longer/higher, when pooled across overground surfaces. Conflicting findings were reported for amplitude of muscle activity.
Conclusions
Spatiotemporal, kinematic, kinetic, muscle activity, and muscle–tendon outcome measures are largely comparable between motorized treadmill and overground running. Considerations should, however, particularly be given to sagittal plane kinematic differences at footstrike when extrapolating treadmill running biomechanics to overground running. Protocol registration CRD42018083906 (PROSPERO International Prospective Register of Systematic Reviews).
... However, still this is debated that what neuromuscular changes will created in result of biomechanics alterations on the treadmill (25). Hong et al. (2012) and Baur et al. (2007) reported that the maximum plantar pressure is reduced while running on the treadmill in comparison to other surfaces (5,4). Though, if we accept the biomechanical differences between treadmill and overground running conditions, then we should expect changes in muscles activation. ...
... However, still this is debated that what neuromuscular changes will created in result of biomechanics alterations on the treadmill (25). Hong et al. (2012) and Baur et al. (2007) reported that the maximum plantar pressure is reduced while running on the treadmill in comparison to other surfaces (5,4). Though, if we accept the biomechanical differences between treadmill and overground running conditions, then we should expect changes in muscles activation. ...
... However, still this is debated that what neuromuscular changes will created in result of biomechanical changes on the treadmill (24). Results of Hong et al. (2012) and Baur et al (2007) showed that the maximum pressure of foot and the maximum force of foot plantar are reduced while running on the treadmill in comparison to other surfaces (5,4). ...
... Treadmill runners consistently have reduced vertical oscillations in their center of mass and a reduced forefoot loading, which suggest that all or part of the triceps surae is less active. This was supported by Bauret et al. [9] who observed a decrease in soleus muscle activation during push-off phase of T. The same study reported increased activity in the soleus and peroneuslongus muscles during the weight acceptance phase during T, suggesting T requires more stability than O [9]. ...
... Treadmill runners consistently have reduced vertical oscillations in their center of mass and a reduced forefoot loading, which suggest that all or part of the triceps surae is less active. This was supported by Bauret et al. [9] who observed a decrease in soleus muscle activation during push-off phase of T. The same study reported increased activity in the soleus and peroneuslongus muscles during the weight acceptance phase during T, suggesting T requires more stability than O [9]. ...
... The findings of this study are similar to Wank et al. [12] and Baur et al. [9] who observed only small differences in muscle activation of the soleus, gluteus maximus and gastrocnemius muscles and the anteriortibialis muscle, respectively. Contrasting the results of this paper, Wank et al. [12] found significant differences in muscle activation of the rectus femoris with an increase during ground contact and initial swing phases during T. Furthermore, Baur et al. [9] viewed an increase in soleus muscle activation during push-off and a decrease in soleus activity during weight acceptance while O. ...
... Wank et al. [4] have reported similar results between these two running conditions. Conversely, Baur and Hirschmüller [8] have shown specific changes, such as an earlier and longer EMG activity for peroneus longus, and a reduced amplitude for soleus during treadmill running. These previous studies analysed surface EMG from lower limb muscles separately, and the conclusions were restricted to the independent results of individual muscles. ...
... Movement stability during treadmill running might be compromised by changes in speed perception [40] and a reduction of optical flow [41]. Consequently, runners adopt a flatter foot position for landing, assuming a more cautious running style for optimizing stability [4,8,42]. On the other hand, overground running is performed over a stable surface and we speculate that runners may be more comfortable to vary lower limb muscle activation at initial contact. ...
... We found reduced EMG activity during treadmill running for the ankle joint muscles (TA, PER and SO) using single-muscle analysis. These results corroborate a study from Baur and co-workers [8] who found reduced SO EMG during treadmill running, concomitant to longer PER EMG. The authors associated changes in SO EMG to mechanical requirements for running on a moving belt, which reduced the excitability of Golgi tendon organs from the muscle and consequently increases the afferent feedback. ...
... With advances in technology, sEMG measurements have evolved from tethered systems to data loggers (wireless telemetry) and more recently, to fully wireless systems. For the analysis of sprinting, wireless systems are particularly useful since they do not constrain the movement and facilitate ecologically valid data capture, such as the athlete sprinting on a track rather than on a treadmill in a laboratory setting (Baur, Hirschmuller, Muller, Gollhofer, & Mayer, 2007;Savelberg, Vorstenbosch, Kamman, van de Weijer, & Schambardt, 1998; To advance technical knowledge of coaches and athletes, there is a need to understand muscle activation sequences and timing in sprinting, and wireless EMG data could augment understanding of sprinting together with the existing kinematics and kinetic analyses of sprinting derived from many studies. Since the muscles generate the forces required for running there is a particular need to gain knowledge of the timings and sequencing of muscle activity in unrestricted sprinting across the phases of the running gait cycle. ...
... Yu et al. (2008) examined the kinematics and activations of the hamstrings during over-ground sprinting using sEMG wireless telemetry. Differences in running biomechanics and onset times of muscle activations have been noted between treadmill and overground running (Baur et al., 2007;Wank, Frick, & Schmidtbleicher, 1998 Higashihara et al. (2010) and (Schache et al., 2012) analysed the BF and ST and compared their muscle activity over trials of increased running speed. A potentially greater risk of hamstring strain as sprint speed increased was proposed. ...
... However, these studies all involved the athlete running or walking on a treadmill (Chumanov et al., 2007;Higashihara et al., 2010;Thelen et al., 2005). Very few treadmills allow athletes to reach maximum sprint speed and this limits the ecological validity of treadmill running since sprinting or jogging on a treadmill is not identical with overground sprinting or jogging (Baur et al., 2007;Wank et al., 1998). There may also be potential changes in the muscle activation timings and magnitudes as motorised treadmills also contribute to hip extension, as the belt moves the foot of the participant backwards (Van Caekenberghe, Segers, Aerts, Willems, & De Clercq, 2013). ...
Muscles are the key drivers in any human movement. Since the muscles generate the forces and consequently the impulses to move the athlete from one position to another, it can be useful to study the muscle activity during sports movements to help with optimisation of technique, injury prevention and performance enhancements. Due to recent advances in electromyography (EMG) technologies, muscle activity in sports movement such as shot putting and overground sprinting can now be acquired using wireless surface mount sensors. Previously the use of tethered devices restricted the movements which could be analysed. The aim of this research was to investigate data analysis methods for use with EMG. There is a need to develop an in depth understanding of what EMG data can convey by understanding muscle activations and patterns in various sports movements and techniques.
The research has been implemented by conducting a literature review, a survey and experimental studies to examine EMG signals on shot putting, sprinting and to understand cross-talk. There has been significant work done in understanding the biomechanics of sprinting, with emphasis on kinematics. The literature review on muscle activities in sprinting highlighted the need for wireless devices to allow testing of athletes in ecologically valid environments, rather than on a treadmill which offers little comparison with the environment of the sprinter, and proposed that there existed a bias on the muscles studied which may have been due to technology constraints of tethered systems. The survey of biomechanists gave an insight into the sensor devices utilised, the types of experimental studies being undertaken and the specifications desired in these devices. The study of muscle activations during the glide technique in shot put delivered meaningful activation patterns which coincided with key movements in the technique and augmented previously known kinematic data and anecdotal evidence. The study on muscle activations during maximal sprinting returned similar results, the 50% threshold provided information on the higher volume of muscle activity and these bursts of activity also coincided with key kinematic events. The use of independent component analysis (ICA) was examined to reduce cross-talk during sporting movements and recreating EMG signals due incorrectly positioned electrodes. Few studies have examined ICA with myoelectric signals. This research applies ICA to EMG signals during isometric contractions; small increases in correlation were found in some cases between the output signals and the ideal signals.
The data analysis methods used in this research along with the supporting studies may prove to be a vital aid in supporting practitioners, coaches and athletes in the analysis of shot putting and sprinting using muscle activations and patterns. The thresholding methods used in this work may be useful in future studies to distinguish between low and high volumes of EMG activity in sports movements. It is recommended that future studies examine the muscle activity of specific exercises and compare the activity to that of sports movements to determine which exercises are most suitable in training and for pre-activation. The ICA algorithm should be examined further, to analyse isotonic movements.
... With advances in technology, sEMG measurements have evolved from tethered systems to data loggers (wireless telemetry) and more recently, to fully wireless systems. For the analysis of sprinting, wireless systems are particularly useful since they do not constrain the movement and facilitate ecologically valid data capture, such as the athlete sprinting on a track rather than on a treadmill in a laboratory setting (Baur, Hirschmuller, Muller, Gollhofer, & Mayer, 2007;Savelberg, Vorstenbosch, Kamman, van de Weijer, & Schambardt, 1998;. ...
... Yu et al. (2008) examined the kinematics and activations of the hamstrings during overground sprinting using sEMG wireless telemetry. Differences in running biomechanics and onset times of muscle activations have been observed between treadmill and overground running (Baur et al., 2007;Wank, Frick, & Schmidtbleicher, 1998), since treadmills have limited ecological validity and therefore analysis of overground sprinting is more appropriate and valid . Higashihara et al. (2010) and Schache et al. (2012) analysed the BF and ST and compared their muscle activity over trials of increased running speed, a potentially greater risk of hamstring strain as sprint speed increased was proposed, however it must be noted that although the authors suggest an increased risk it was not directly observed or measured. ...
... However, these studies all involved the athlete running or walking on a treadmill (Chumanov et al., 2007;Higashihara et al., 2010;Thelen et al., 2005). Very few treadmills allow athletes to reach maximum sprint speed and this limits the ecological validity of treadmill running since sprinting or jogging on a treadmill is not identical with overground sprinting or jogging (Baur et al., 2007;Wank et al., 1998). There may also be potential changes in the muscle activation timings and magnitudes as motorised treadmills also contribute to hip extension, as the belt moves the foot of the participant backwards (Van Caekenberghe, Segers, Aerts, Willems, & De Clercq, 2013). ...
The use of electromyography (EMG) is widely recognised as a valuable tool for enhancing the understanding of performance drivers and potential injury risk in sprinting. The timings of muscle activations relative to running gait cycle phases and the technology used to obtain muscle activation data during sprinting are of particular interest to scientists and coaches. This review examined the main muscles being analysed by surface EMG (sEMG), their activations and timing, and the technologies used to gather sEMG during sprinting. Electronic databases were searched using ‘Electromyography’ OR ‘EMG’ AND ‘running’ OR ‘sprinting’. Based on inclusion criteria, 18 articles were selected for review. While sEMG is widely used in biomechanics, relatively few studies have used sEMG in sprinting due to system constraints. The results demonstrated a focus on the leg muscles, with over 70% of the muscles analysed in the upper leg. This is consistent with the use of tethered and data logging EMG systems and many sprints being performed on treadmills. Through the recent advances in wireless EMG technology, an increase in the studies on high velocity movements such as sprinting is expected and this should allow practitioners to perform the analysis in an ecologically valid environment.
... Wank et al. [4] have reported similar results between these two running conditions. Conversely, Baur and Hirschmüller [8] have shown specific changes, such as an earlier and longer EMG activity for peroneus longus, and a reduced amplitude for soleus during treadmill running. These previous studies analysed surface EMG from lower limb muscles separately, and the conclusions were restricted to the independent results of individual muscles. ...
... Movement stability during treadmill running might be compromised by changes in speed perception [40] and a reduction of optical flow [41]. Consequently, runners adopt a flatter foot position for landing, assuming a more cautious running style for optimizing stability [4,8,42]. On the other hand, overground running is performed over a stable surface and we speculate that runners may be more comfortable to vary lower limb muscle activation at initial contact. ...
... We found reduced EMG activity during treadmill running for the ankle joint muscles (TA, PER and SO) using single-muscle analysis. These results corroborate a study from Baur and co-workers [8] who found reduced SO EMG during treadmill running, concomitant to longer PER EMG. The authors associated changes in SO EMG to mechanical requirements for running on a moving belt, which reduced the excitability of Golgi tendon organs from the muscle and consequently increases the afferent feedback. ...
Motorized treadmills have been widely used in locomotion studies, although a debate remains concerning the extrapolation of results obtained from treadmill experiments to overground locomotion. Slight differences between treadmill (TRD) and overground running (OVG) kinematics and muscle activity have previously been reported. However, little is known about differences in the modular control of muscle activation in these two conditions. Therefore, we aimed at investigating differences between motor modules extracted from TRD and OVG by factorization of multi-muscle electromyographic (EMG) signals. Twelve healthy men ran on a treadmill and overground at their preferred speed while we recorded tibial acceleration and surface EMG from 11 ipsilateral lower limb muscles. We extracted motor modules representing relative weightings of synergistic muscle activations by non-negative matrix factorization from 20 consecutive gait cycles. Four motor modules were sufficient to accurately reconstruct the EMG signals in both TRD and OVG (average reconstruction quality = 92±3%). Furthermore, a good reconstruction quality (80±7%) was obtained also when muscle weightings of one condition (either OVG or TRD) were used to reconstruct the EMG data from the other condition. The peak amplitudes of activation signals showed a similar timing (pattern) across conditions. The magnitude of peak activation for the module related to initial contact was significantly greater for OVG, whereas peak activation for modules related to leg swing and preparation to landing were greater for TRD. We conclude that TRD and OVG share similar muscle weightings throughout motion. In addition, modular control for TRD and OVG is achieved with minimal temporal adjustments, which were dependent on the phase of the running cycle.
... Peak vertical force (through) (White et al., 1998) Second vertical peak (White et al., 1998), Shock attenuation (Hines and Mercer, 2004) Max braking force (Lee and Hidler, 2008) Peak anterior GRF Peak medial GRF JOINT KINETICS Ankle dorsiflexion moment loading response (Lee and Hidler, 2008) Knee max extension moment (Lee and Hidler, 2008) Max knee flexion moment late stance (Lee and Hidler, 2008) Max knee flexion moment late swing (Lee and Hidler, 2008) Tibial strain (Milgrom, 2003) Knee varus moment Ankle plantarflexion moment Knee power generation Ankle power absorption TM>OV TM<OV TM>OV TM<OV TM>OV TM<OV m. biceps femoris during final swing ) Onset of m. peroneus longus (Baur et al., 2007) Timing of maximal m. peroneus longus (Baur et al., 2007) Total activation time of m. peroneus longus (Baur et al., 2007) Amplitude of m. soleus during push off (Baur et al., 2007) m. tibialis anterior during stance (Lee and Hidler, 2008) m. gastrocnemius during stance except final swing (Lee and Hidler, 2008) m. gastrocnemius final swing (Lee and Hidler, 2008) m. rectus femoris (Lee and Hidler, 2008) m. rectus femoris of swing leg during ground contact Hamstrings + vasti + adductors during early and midswing (Lee and Hidler, 2008) Hamstrings + vasti + adductors during final swing (Lee and Hidler, 2008) Hamstrings activation of the stance leg Vasti activation during stance TM>OV TM<OV TM>OV TM<OV TM>OV TM<OV Oxygen intake , , ) , (Daniels et al., 1953) Heart rate , , ...
... Peak vertical force (through) (White et al., 1998) Second vertical peak (White et al., 1998), Shock attenuation (Hines and Mercer, 2004) Max braking force (Lee and Hidler, 2008) Peak anterior GRF Peak medial GRF JOINT KINETICS Ankle dorsiflexion moment loading response (Lee and Hidler, 2008) Knee max extension moment (Lee and Hidler, 2008) Max knee flexion moment late stance (Lee and Hidler, 2008) Max knee flexion moment late swing (Lee and Hidler, 2008) Tibial strain (Milgrom, 2003) Knee varus moment Ankle plantarflexion moment Knee power generation Ankle power absorption TM>OV TM<OV TM>OV TM<OV TM>OV TM<OV m. biceps femoris during final swing ) Onset of m. peroneus longus (Baur et al., 2007) Timing of maximal m. peroneus longus (Baur et al., 2007) Total activation time of m. peroneus longus (Baur et al., 2007) Amplitude of m. soleus during push off (Baur et al., 2007) m. tibialis anterior during stance (Lee and Hidler, 2008) m. gastrocnemius during stance except final swing (Lee and Hidler, 2008) m. gastrocnemius final swing (Lee and Hidler, 2008) m. rectus femoris (Lee and Hidler, 2008) m. rectus femoris of swing leg during ground contact Hamstrings + vasti + adductors during early and midswing (Lee and Hidler, 2008) Hamstrings + vasti + adductors during final swing (Lee and Hidler, 2008) Hamstrings activation of the stance leg Vasti activation during stance TM>OV TM<OV TM>OV TM<OV TM>OV TM<OV Oxygen intake , , ) , (Daniels et al., 1953) Heart rate , , ...
... Peak vertical force (through) (White et al., 1998) Second vertical peak (White et al., 1998), Shock attenuation (Hines and Mercer, 2004) Max braking force (Lee and Hidler, 2008) Peak anterior GRF Peak medial GRF JOINT KINETICS Ankle dorsiflexion moment loading response (Lee and Hidler, 2008) Knee max extension moment (Lee and Hidler, 2008) Max knee flexion moment late stance (Lee and Hidler, 2008) Max knee flexion moment late swing (Lee and Hidler, 2008) Tibial strain (Milgrom, 2003) Knee varus moment Ankle plantarflexion moment Knee power generation Ankle power absorption TM>OV TM<OV TM>OV TM<OV TM>OV TM<OV m. biceps femoris during final swing ) Onset of m. peroneus longus (Baur et al., 2007) Timing of maximal m. peroneus longus (Baur et al., 2007) Total activation time of m. peroneus longus (Baur et al., 2007) Amplitude of m. soleus during push off (Baur et al., 2007) m. tibialis anterior during stance (Lee and Hidler, 2008) m. gastrocnemius during stance except final swing (Lee and Hidler, 2008) m. gastrocnemius final swing (Lee and Hidler, 2008) m. rectus femoris (Lee and Hidler, 2008) m. rectus femoris of swing leg during ground contact Hamstrings + vasti + adductors during early and midswing (Lee and Hidler, 2008) Hamstrings + vasti + adductors during final swing (Lee and Hidler, 2008) Hamstrings activation of the stance leg Vasti activation during stance TM>OV TM<OV TM>OV TM<OV TM>OV TM<OV Oxygen intake , , ) , (Daniels et al., 1953) Heart rate , , ...
... /14763141.2014 repeatability of the trials, easier instrumentation, better control of the environment (temperature, humidity), speed, and slope, and less space required (Baur, Hirschmü ller, Mü ller, Gollhofer, & Mayer, 2007;Lavcanska, Taylor, & Schache, 2005;Nigg, De Boer, & Fisher, 1995;Riley et al., 2008;Savelberg et al., 1998;Schache et al., 2001;Wank, Frick, & Schmidtbleicher, 1998). But the experimental evidence that the treadmill can modify the basic running pattern should be taken into account when interpreting the results of studies conducted on this surface (Savelberg et al., 1998). ...
... But the experimental evidence that the treadmill can modify the basic running pattern should be taken into account when interpreting the results of studies conducted on this surface (Savelberg et al., 1998). In particular, several important biomechanical variables may be affected by the treadmill, such as stride frequency (Reinisch et al., 1991;Riley et al., 2008;Schache et al., 2001;Wank et al., 1998), contact time (García-Pérez et al., 2013;McKenna & Riches, 2007;Schache et al., 2001;Wank et al., 1998), lower extremity joint kinematics in the sagittal plane (Riley et al., 2008;Schache et al., 2001;Wank et al., 1998), muscular activity (Baur et al., 2007;Wank et al., 1998), energy expenditure (Pugh, 1970), shock attenuation (Hines & Mercer, 2004), and plantar pressures (Baur et al., 2007;García-Pérez et al., 2013). Even though the existing literature indicates that different running surfaces may lead to biomechanically different running patterns, some authors still consider that treadmill running may be a representative expression of overground running (Riley et al., 2008;Schache et al., 2001). ...
... But the experimental evidence that the treadmill can modify the basic running pattern should be taken into account when interpreting the results of studies conducted on this surface (Savelberg et al., 1998). In particular, several important biomechanical variables may be affected by the treadmill, such as stride frequency (Reinisch et al., 1991;Riley et al., 2008;Schache et al., 2001;Wank et al., 1998), contact time (García-Pérez et al., 2013;McKenna & Riches, 2007;Schache et al., 2001;Wank et al., 1998), lower extremity joint kinematics in the sagittal plane (Riley et al., 2008;Schache et al., 2001;Wank et al., 1998), muscular activity (Baur et al., 2007;Wank et al., 1998), energy expenditure (Pugh, 1970), shock attenuation (Hines & Mercer, 2004), and plantar pressures (Baur et al., 2007;García-Pérez et al., 2013). Even though the existing literature indicates that different running surfaces may lead to biomechanically different running patterns, some authors still consider that treadmill running may be a representative expression of overground running (Riley et al., 2008;Schache et al., 2001). ...
... In the kinematic analysis of a study, no significant difference was found in vertical ground reaction force between treadmill and overground running at a constant running speed [7]. In addition, several studies observed an in-shod plantar pressure during treadmill and overground running [8,9]. These studies found that compared with overground running, treadmill running has a lower magnitude of maximum plantar pressure at the plantar area. ...
... These studies found that compared with overground running, treadmill running has a lower magnitude of maximum plantar pressure at the plantar area. Kinematic changes in the ankle joint complex during treadmill running attribute the difference in the plantar pressure [8,9]. Furthermore, the manifestation of biomechanics changes in treadmill running in the changes in neuromuscular activation is still under debate [6,8]. ...
... Kinematic changes in the ankle joint complex during treadmill running attribute the difference in the plantar pressure [8,9]. Furthermore, the manifestation of biomechanics changes in treadmill running in the changes in neuromuscular activation is still under debate [6,8]. ...
The objective of this study is to compare the muscular activity of lower extremity muscles while running on treadmill and on overground surfaces. A total of 13 experienced heel-to-toe runners participated in the study. Electromyographic (EMG) data of four lower extremity muscles, including rectus femoris, tibialis anterior, biceps femoris, and gastrocnemius, were collected using the Noraxon EMG system while running on a treadmill and on overground surfaces at a running speed of 3.8 m/s. The obtained data were then analyzed. In this study, throughout the stance phase, the EMG values in the rectus femoris (P<0.01) and the biceps femoris (P<0.05) were higher while running on overground surfaces than those on a treadmill. The EMG values in the rectus femoris (P<0.05) and the biceps femoris (P<0.05) were also higher on concrete than those on grass in the stance phase. Results showed that the muscle activity was significantly different in treadmill running than in overground running. The difference in muscle activity while running on different overground surfaces was also found in this study. Kinematic adjustment of the lower extremity may explain the EMG difference while running on different surfaces.
... Properties of different surfaces provoke biomechanical modifications in running gait [1], making the running surface an essential aspect to consider when designing the methodology of gait analysis. Within this area of research, the use of treadmills is becoming ever commoner [2][3][4][5] since it provides numerous methodological advantages -less space required, repeatability, and better control of climatological aspects, speed, slope, etc., as well as easier instrumentation of the runner [2][3][4][6][7][8]. However, the generalization of results from studies that analyze running on a treadmill may become controversial if treadmill and overground running biomechanics are not proven to be equivalent [4,8]. ...
... However, the generalization of results from studies that analyze running on a treadmill may become controversial if treadmill and overground running biomechanics are not proven to be equivalent [4,8]. In this sense, there is evidence showing differences when running on a treadmill and overground in several variables -stride frequency [3,5,8,9], contact time [5,8,10], ankle, knee, and hip kinematics [3,5,7,8,11], muscular activity [5,6], energy expenditure [12], shock attenuation [13], and plantar pressures [6,14]. These differences could be due to treadmill familiarization [2], intra-stride treadmill speed variations because of the interaction between the runner and the device [4], air resistance [12], and the runner trying to reach a stable and safe running pattern on the treadmill [5][6][7]. ...
... However, the generalization of results from studies that analyze running on a treadmill may become controversial if treadmill and overground running biomechanics are not proven to be equivalent [4,8]. In this sense, there is evidence showing differences when running on a treadmill and overground in several variables -stride frequency [3,5,8,9], contact time [5,8,10], ankle, knee, and hip kinematics [3,5,7,8,11], muscular activity [5,6], energy expenditure [12], shock attenuation [13], and plantar pressures [6,14]. These differences could be due to treadmill familiarization [2], intra-stride treadmill speed variations because of the interaction between the runner and the device [4], air resistance [12], and the runner trying to reach a stable and safe running pattern on the treadmill [5][6][7]. ...
The differences produced when running on a treadmill vs overground may call into question the use and validity of the treadmill as a piece of equipment commonly used in research, training, and rehabilitation. The aim of the present study was to analyze under pre/post fatigue conditions the effect of treadmill vs overground on plantar pressures. Twenty-seven recreational runners (17 men and 10 women) ran on a treadmill and overground at two speeds: S1=3.33m/s and S2=4.00m/s, before and after a fatigue protocol consisting of a 30-min run at 85% of their individual maximal aerobic speed (MAS). Contact time (CT in seconds), peak pressure (PP in kPa), and relative load (RL in %) were analyzed under nine foot zones of the left foot using an in-shoe plantar pressure device. A two-way repeated measures ANOVA showed that running on a treadmill increases CT (7.70% S1 and 9.91% S2), modifies the pressure distribution and reduces PP (25.98% S1 and 31.76% S2), especially under the heel, medial metatarsals, and hallux, compared to running overground. Moreover, on both surfaces, fatigue (S2) led to a reduced stride frequency (2.78%) and reduced PP on the lateral heel and hallux (15.96% and 16.35%, respectively), and (S1) increased relative load on the medial arch (9.53%). There was no significant interaction between the two factors analyzed (surface and fatigue). Therefore, the aforementioned surface effect, which occurs independently of the fatigue state, should be taken into account when interpreting the results of studies that use the treadmill in their experimental protocols, and when prescribing physical exercise on a treadmill.
... A convenient way to assess inter-muscular coordination non-invasively is through recordings of surface electromyography (sEMG), which provides indirect estimation of neural input to muscles (Chapman et al. 2010;Lacquaniti et al. 2012). However, only a few studies have compared the activation of different lower limb muscles while running on different surfaces (Baur et al. 2007;Wank et al. 1998). It has been shown that rectus femoris and biceps femoris present greater activation while running on concrete running compared to treadmill or grass (Wang et al. 2014), despite predominantly similar lower limb EMG patterns between overground and treadmill running (Wank et al. 1998). ...
... This difference may be related to the runner's attempt to find optimal strategies to cope with the constant belt speed (Loeb 2012) regarding the surface. Treadmill running may demand distinct patterns of segment coordination (Abbasi et al. 2020) and foot contact accommodation (Chiu et al. 2015) when compared to overground running, due to unique mechanical adjustments required to maintain the running speed imposed by the moving belt (Baur et al. 2007). The modulation of inter-muscular coordination during locomotion relies on essential inputs from the sensory system (Cheung et al. 2005). ...
Running is an exercise that can be performed in different environments that imposes distinct foot–floor interactions. For instance, running on grass may help reducing instantaneous vertical impact loading, while compromising natural speed. Inter-muscular coordination during running is an important factor to understand motor performance, but little is known regarding the impact of running surface hardness on inter-muscular coordination. Therefore, we investigated whether inter-muscular coordination during running is influenced by running surface. Surface electromyography (EMG) from 12 lower limb muscles were recorded from young male individuals (n = 9) while running on grass, concrete, and on a treadmill. Motor modules consisting of weighting coefficients and activation signals were extracted from the multi-muscle EMG datasets representing 50 consecutive running cycles using non-negative matrix factorization. We found that four motor modules were sufficient to represent the EMG from all running surfaces. The inter-subject similarity across muscle weightings was the lowest for running on grass (r = 0.76 ± 0.11) compared to concrete (r = 0.81 ± 0.07) and treadmill (r = 0.78 ± 0.05), but no differences in weighting coefficients were found when analyzing the number of significantly active muscles and residual muscle weightings (p > 0.05). Statistical parametric mapping showed no temporal differences between activation signals across running surfaces (p > 0.05). However, the activation duration (% time above 15% peak activation) was significantly shorter for treadmill running compared to grass and concrete (p < 0.05). These results suggest predominantly similar neuromuscular strategies to control multiple muscles across different running surfaces. However, individual adjustments in inter-muscular coordination are required when coping with softer surfaces or the treadmill’s moving belt.
... Although running speed was strictly controlled across conditions in our study, participants might have changed their running kinematics, especially on the treadmill. It has been reported that treadmill speed can be maintained with a shorter propulsive phase when compared to overground running (Baur et al., 2007), also a reduction in the braking phase duration during treadmill running minimizes backward and forward motion due to the moving belt (García-Pérez et al., 2014). ...
... The muscles tibialis anterior, gastrocnemius lateralis, and gastrocnemius medialis showed lower AVR CV variability during treadmill running, which may be related to distinct postural control strategies when the running speed is imposed by the moving belt (Baur et al., 2007). In addition, the greater AVR CV for tibialis anterior during running on grass compared to concrete may be related to greater need for ankle stability on grass. ...
This study aimed to investigate whether inter-trial variability in muscle activity (electromyography, EMG) during running is influenced by the number of acquired steps and running surface. Nine healthy participants ran at preferred speed on treadmill, concrete, and grass. Tibial acceleration and surface EMG from 12 lower limb muscles were recorded. The coefficient of variation (CV) from the average EMG and peak EMG were computed from 5, 10, 25, 50 and 100 steps in each running surface. Data average stability was computed using sequential estimation technique (SET) from 100 steps. The CV for average and peak EMG was lower during treadmill running compared to running on grass (-11±2.88%) or concrete (-9±2.94%) (p<0.05), without differences across the different number of steps. Moreover, the peak EMG CV from peroneus longus was lower on concrete (p<0.05), whereas gluteus maximus presented greater variability on grass compared to concrete (p<0.05). The SET analysis revealed that average stability is reached with up to 10 steps across all running conditions. Therefore, treadmill running induced greater variability compared to overground, without influence of the number of steps on EMG variability. Moreover, average stability for EMG recordings may be reached with up to 10 steps.
... As mentioned above, studies have not resolved the question of whether the mechanics of running on a treadmill can replicate those of overground running [1,3]. So far, studies have investigated issues such as the kinematic adaptations and kinetics of running, as well as neuromuscular adaptations and differences in the activities of various muscles under different substrates in running [3,4,[13][14][15]. ...
... An even more important factor is the effect of fatigue on the biomechanics of running. Such effects may start by a change in the angle of the runner's foot with the running substrate, then a change in the distribution of pressure at the plantar area, followed by a change in the reaction forces, or a change in the pattern of muscular activity and neuromuscular control depending on the running surface [13]. Plantar pressure is routinely used for the measurement and analysis of running on a treadmill or overground surface for the prevention of injury, increasing athletic performance, and designing new sports materials. ...
Purpose: This study aimed to compare the effects of fatigue due to overground and treadmill running on the plantar pressure distribution pattern.
Methods: Twelve novice athletes (Mean±SD age=26.0±2.5 y, Mean±SD weight: 52.0±3.0 kg, Mean±SD height: 159.0±5.0 cm), without sports injuries over the past year, were selected. Overground and treadmill running created fatigue in the samples. Peak plantar pressure distribution, Center of Pressure, contact area, and impulse the samples were recorded using a footscan (Footscan Version 7 Gait 2nd generation software) pressure system during running before and after the fatigue protocol and analyzed with repeated measures ANOVA in SPSS v. 18.
Results: Peak plantar pressure on the second to fifth toe , the fourth and fifth metatarsal bones, and medial part of the heel significantly increased. The shift in the Center of Pressure of the foot was non-significant in all stages. The contact area at the second metatarsal and midfoot area shifted only before the fatigue protocol on overground running. Impulse at the second to fifth toe, first to fifth metatarsal, significantly increased in the ground running.
Conclusion: The results showed that fatigue due to treadmill running has different effects compared to fatigue due to overground running.
... In sprinting, the data collection process is more challenging with tethered and data logging systems, due to wires and data loggers causing encumbrances. Furthermore, the use of a treadmill especially when sprinting is likely to cause changes in the way the athlete will run (Baur, Hirschmuller, Muller, Gollhofer, & Mayer, 2007;Savelberg, Vorstenbosch, Kamman, van de Weijer, & Schambardt, 1998;Wank, Frick, & Schmidtbleicher, 1998). Consequently, sprint monitoring of muscle activations and performance would be better achieved in an ecologically valid environment such as the track rather than a laboratory setting (Baur et al., 2007;Van Caekenberghe et al., 2013). ...
... Furthermore, the use of a treadmill especially when sprinting is likely to cause changes in the way the athlete will run (Baur, Hirschmuller, Muller, Gollhofer, & Mayer, 2007;Savelberg, Vorstenbosch, Kamman, van de Weijer, & Schambardt, 1998;Wank, Frick, & Schmidtbleicher, 1998). Consequently, sprint monitoring of muscle activations and performance would be better achieved in an ecologically valid environment such as the track rather than a laboratory setting (Baur et al., 2007;Van Caekenberghe et al., 2013). ...
http://www.tandfonline.com/doi/ref/10.1080/14763141.2016.1174289
This paper examines the use of sensor devices in sports biomechanics, focusing on current frequency of use of Electromyography (EMG) device preferences. Researchers in the International Society of Biomechanics in Sports were invited to participate in an online survey. Responses on multiple sensor devices highlighting frequency of use, device features and improvements researchers sought in acquisition and analysis methods were obtained via an online questionnaire. Results of the investigation showed that the force platform is the most frequently used device, with inertial measurement units and EMG devices growing in popularity. Wireless functionality and ease of use for both the participant and the practitioner proved to be important features. The main findings of the survey demonstrated need for a simple, low power, multi-channel device which incorporates the various sensors into one single device. Biomechanists showed they were looking for more availability of wireless sensor devices with acquisition and analysis features. The study found there is a need to develop software analysis tools to accompany the multi-channel device, providing all the basic functions while maintaining compatibility with existing systems.
... All further EMG data recordings and analyses were processed using the MyoResearch software. Raw data were full-wave rectified, then smoothed using a moving average at 50 points (Baur, Hirschmuller, Muller, Gollhofer, & Mayer, 2007). The webcam was synchronized with the EMG data within the MyoResearch software. ...
... The highest of those peak EMG values was used for onset calculations. Onset values were identified as EMG values above 10% of the maximal EMG signal observed (during all five MW trials) for at least 10 ms, based on previous research (Baur et al., 2007;O'Connor, Price, & Hamill, 2006;Paredes & Opavsky, 2010). Onset time was defined as the amount of time(s) from heel strike until muscle onset. ...
An external focus of attention has been shown to improve balance measures during static postural tasks. The purpose of this study was to evaluate the effects of different attentional focus strategies in response to a perturbation while performing a dynamic balance task. Participants (n = 29) performed a dynamic balance task that consisted of stepping onto an uneven surface while attempting to continuously walk in a straight line. The orientation of the surface was unknown to the participants. During the external focus conditions, participants were instructed to focus on the surface they walked on. During the internal focus conditions, participants were instructed to focus on keeping their body over their feet. Analyses revealed that the external focus condition exhibited significantly less lateral displacement from the intended walking line following the perturbation (4.56 ± 2.56 cm) than the internal (5.61 ± 2.89 cm, p = .019) and baseline (6.07 ± 2.6 cm, p = .004) conditions. These data indicate that participants were more resilient to the perturbing surface when their attention was focused on external information. Thus, participants were able to respond to a perturbation more effectively when utilizing an external focus of attention.
... The lower peak impact acceleration and impact rate observed in the treadmill case may in part be a consequence of greater effective mass at foot-strike (McKenna & Riches, 2007;Reinisch et al., 1991), which in itself would not necessarily imply lesser ground reaction forces (Derrick, 2004;Derrick et al., 2002). Peak pressure and reaction force are strongly correlated, however, and treadmill running has lower peak pressures than overground running (Baur et al., 2007;García-Pérez et al., 2013). One infers, therefore, that the lower pre-fatigue accelerations recorded in the treadmill case were not only due to such a difference in the effective mass, but also to lower reaction forces. ...
... Indeed, the effect in this sense would be double because not only is the runner able to maintain treadmill speed with less propulsive phase than when running overground (Baur et al., 2007;Reinisch et al., 1991;Savelberg et al., 1998), but the braking phase of the running gait would also be reduced so as not to move backwards and forwards on the moving belt. ...
The effects of treadmill running on impact acceleration were examined together with the interaction between running surface and runner's fatigue state. Twenty recreational runners (11 men and 9 women) ran overground and on a treadmill (at 4.0 m/s) before and after a fatigue protocol consisting of a 30-minute run at 85% of individual maximal aerobic speed. Impact accelerations were analysed using two lightweight capacitive uniaxial accelerometers. A two-way repeated-measure analysis of variance showed that, in the pre-fatigue condition, the treadmill running decreased head and tibial peak impact accelerations and impact rates (the rate of change of acceleration), but no significant difference was observed between the two surfaces in shock attenuation. There was no significant difference in acceleration parameters between the two surfaces in the post-fatigue condition. There was a significant interaction between surface (treadmill and overground) and fatigue state (pre-fatigue and post-fatigue). In particular, fatigue when running overground decreased impact acceleration severity, but it had no such effect when running on the treadmill. The effects of treadmill running and the interaction need to be taken into account when interpreting the results of studies that use a treadmill in their experimental protocols, and when prescribing physical exercise.
... Previous studies investigated a number of kinematic parameters involved in treadmill training as well as in overground training. These parameters include the knee in the sagittal plane, movements at the ankle joint, and kinematics of the lumbo-pelvic-hip complex (Baur et al., 2007; Bickham, 2000; McKenna and Riches, 2007; Riley et al., 2008; Riley et al., 2010; Schache et al., 1999; 2003; 2005; Vogt et al., 2002). Furthermore, few studies have investigated lower limb muscular involvement in overground and treadmill training as well as hamstring strength with various training modes (Croisier et al., 2007; Gajdosik et al., 1985; Koller et al., 2006). ...
... Non-motorized treadmills have a curved surface without a motor which requires the runner to stride on the surface and propel the belt with each stride. Past studies have concluded when running on a motorized treadmill there is a more pronounced forward leaning of the upper torso (Baur et al., 2007; Tong et al., 2001). With this forward leaning posture, muscles of the erector spinae as well as paraspinals are placed on stretch and hip flexors are in a more shortened position. ...
Unlabelled:
Previous literature suggests that muscular involvement and biomechanical changes elicit different responses between overground and treadmill training. The objective of this study was to examine the effects of training on two different treadmill designs on the conventional (CR; concentric only) and functional (FR; eccentric to concentric) hamstring and quadriceps strength ratios. Fifteen men and sixteen women were randomly divided into three groups: motorized (MT), non-motorized (NMT) or control (C). Subjects completed pre and post-test isokinetic concentric and eccentric quadriceps and hamstring testing of both legs. Subjects completed 4 weeks of training on their respective treadmills with mileage increasing ½ mile each week, beginning with 2 miles. The C group did not participate in any training. The CR revealed a significant two way interaction of group x time with MT increasing (pre: 0.80 ± 0.09 to post: 0.84 ± 0.09), NMT decreasing (pre: 0.76 ± 0.13 to post: 0.74 ± 0.10), and C showing no change (pre: 0.79 ± 0.10 to post: 0.79 ± 0.09. The FR revealed a significant two way interaction of speed x sex with the FR increasing as speeds increased for men (60 degrees.s(-1): 1.04 ± 0.11; 180 degrees.s(-1): 1.66 ± 0.27; 300 degrees.s(-1): 2.36 ± 0.45) and women (60 degrees.s(-1): 1.05 ± 0.16; 180 degrees.s(-1): 1.90 ± 0.26; 300 degrees.s(-1): 2.75 ± 0.47) but women increased greater relative to men. Training mode elicited a specific change in concentric hamstring and quadriceps strength resulting in specific changes to the CR; however, neither training mode had an effect on eccentric hamstrings nor the FR. Special attention should be given to the mode of endurance training when the goal is to alter the hamstring/quadriceps CR.
Key points:
Specificity of treadmill training had different effects on concentric strength.Specificity of treadmill training had little or no effect on eccentric strength.Conventional and functional strength ratios may give different results based on training mode.Four weeks is long enough for strength results to be apparent in untrained people.
... Treadmill running biomechanics may differ from overground running (Sinclair et al., 2013;Van Hooren et al., 2020) during the foot strike, in terms of peak propulsive force and sagittal plane joint kinematics like hip flexion/extension angles and ROM, knee flexion angle and ROM, foot strike angle, and COM vertical displacement. While debated (Van Hooren et al., 2020), some studies also indicate differences in muscle activity, impact peak GRF, and tibial forces (Milgrom et al., 2003;Kluitenberg et al., 2012;Baur et al., 2018). To investigate if these differences modulate the influence of fatigue on running, we computed summary trends for the treadmill and overground running studies separately. ...
Objective: To investigate (i) typical protocols used in research on biomechanical response to running-induced fatigue, (ii) the effect of sport-induced acute fatigue on the biomechanics of running and functional tests, and (iii) the consistency of analyzed parameter trends across different protocols.
Methods: Scopus, Web of Science, Pubmed, and IEEE databases were searched using terms identified with the Population, Interest and Context (PiCo) framework. Studies were screened following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and appraised using the methodological index for non-randomized studies MINORS scale. Only experimental studies with at least 10 participants, which evaluated fatigue during and immediately after the fatiguing run were included. Each study was summarized to record information about the protocol and parameter trends. Summary trends were computed for each parameter based on the results found in individual studies.
Results: Of the 68 included studies, most were based on in-lab (77.9%) protocols, endpoint measurements (75%), stationary measurement systems (76.5%), and treadmill environment (54.4%) for running. From the 42 parameters identified in response to acute fatigue, flight time, contact time, knee flexion angle at initial contact, trunk flexion angle, peak tibial acceleration, CoP velocity during balance test showed an increasing behavior and cadence, vertical stiffness, knee extension force during MVC, maximum vertical ground reaction forces, and CMJ height showed a decreasing trend across different fatigue protocols.
Conclusion: This review presents evidence that running-induced acute fatigue influences almost all the included biomechanical parameters, with crucial influence from the exercise intensity and the testing environment. Results indicate an important gap in literature caused by the lack of field studies with continuous measurement during outdoor running activities. To address this gap, we propose recommendations for the use of wearable inertial sensors.
... Due to the size and physical setup of the recording system, we measured EMG activity while subjects ran on a treadmill in a laboratory setting. It is possible that our results might differ if we performed the same analysis during overground locomotion, although current opinions differ as to whether EMG data recorded in each condition appreciably differ (Baur et al., 2018;Wang et al., 2014;Wank et al., 1998). Future advancements in high-density EMG technology will allow researchers to become more mobile, and muscle recruitment can then be studied in real-world environments. ...
The spatial distribution of myoelectric activity within lower limb muscles is often nonuniform and can change during different stationary tasks. Recent studies using high-density electromyography (EMG) have suggested that spatial muscle activity may also differ among muscles during locomotion, but contrasting electrode array sizes and experimental designs have limited cross-study comparisons. Here, we sought to determine if spatial EMG patterns differ among lower limb muscles and locomotion speeds. We recorded high-density EMG from the vastus medialis, tibialis anterior, biceps femoris, medial gastrocnemius, and lateral gastrocnemius muscles of 11 healthy subjects while they walked (1.2 and 1.6 m/s) and ran (2.0, 3.0, 4.0, and 5.0 m/s) on a treadmill. To overcome the detrimental effects of cable, electrode, and soft tissue movements on high-density EMG signal quality during locomotion, we applied multivariate signal cleaning methods. From these data, we computed the spatial entropy and center of gravity from the total myoelectric activity within each recording array during the stance or swing phases of the gait cycle. We found heterogeneous spatial EMG patterns evidenced by contrasting spatial entropy among lower limb muscles. As locomotion speed increased, mean entropy values decreased in four of the five recorded muscles, indicating that EMG signal amplitudes were more spatially heterogeneous, or localized, at faster speeds. The EMG center of gravity location also shifted in multiple muscles as locomotion speed increased. Contrasting myoelectric spatial distributions among muscles likely reflect differences in muscle architecture, but increasingly localized activity and spatial shifts in the center of gravity location at faster locomotion speeds could be influenced by preferential recruitment of faster motor units under greater loads.
... It is beyond the scope of this study to discuss potential limitations of our instrumented sprint treadmill, including how effective this methodology actually replicates sprinting in an ecological situation (Morin and Sève 2011;Morin et al. 2015). Differences in running biomechanics and onset times of muscle activations exist between treadmill and overground running (Baur et al. 2007;Miller et al. 2019), the former favoring slight external assistance to the stance backward action of the leg. Therefore, it cannot be ruled out that sprint kinetics/kinematics and accompanying muscle activity patterns for the very first steps may not be strictly equivalent to those measured with track-embedded force plates (starting-block acceleration) due to the adoption of slightly dissimilar crouched positions. ...
Purpose:
We determined whether running mechanics and leg muscle activity patterns for pre-activation (50 ms prior to foot contact) and loading (first half, second half and entire stance) phases vary between early, late and entire acceleration phases during repeated treadmill sprints.
Methods:
Ten male athletes performed three sets of five 5-s sprint accelerations (25-s and 3-min recovery between sprints and sets, respectively) on an instrumented treadmill. Ground reaction forces and surface EMG data (root mean square values of vastus lateralis, rectus femoris, biceps femoris, gastrocnemius medialis, gastrocnemius lateralis and tibialis anterior muscles of the right leg) corresponding to early, late and entire acceleration (steps 2, 4 and 6; steps 8, 10 and 12; and all steps, respectively) have been compared.
Results:
Independently of fatigue, vertical and horizontal forces, contact time, step length, and step frequency differed as running velocity increased over different sprint acceleration sections (all P < 0.05). For pre-activation, first half, second half and entire stance phases taken separately, each of the six studied muscles displayed specific main sprint number and analysis section effects (all P < 0.05). However, there was in general no significant interaction between sprint number and analysis section (all P > 0.27).
Conclusion:
During repeated treadmill sprints, ground reaction force variables and leg muscle activity patterns can vary between early, late and entire acceleration phases. Identification of neuro-mechanical adjustments across the gait cycle with fatigue, however, did not differ when considering all steps or only a few steps during the early or late acceleration phases.
... Several studies have shown that muscle activity may be different between treadmill and overground running (Baur et al., 2007;Wank et al., 1998) and thus, the results of this study should not be generalized to over ground running. Finally, this study utilized a relatively small sample size. ...
While several studies have examined kinematic and kinetic differences between maximalist (MAX), traditional (TRAD), or partial minimalist (PMIN) shoes, to date it is unknown how MAX shoes influence muscle activity. This study compared lower extremity kinematics and muscle activity when running in PMIN, TRAD, and MAX shoes. Thirteen participants ran in each shoe while whole body kinematics were recorded using motion capture and electromyography was recorded from seven leg muscles. Differences in kinematics and root mean square amplitudes (RMS) were compared between shoe conditions. There were small differences in sagittal and frontal plane ankle kinematics between shoe conditions, with the MAX shoes resulting in less dorsiflexion at foot strike (p = .002) and less peak dorsiflexion (p < .001), and the PMIN shoes resulting in greater peak eversion (p = .012). Gluteus medius (p.006) and peroneus longus (p = .007) RMS amplitudes were greater in the MAX shoe then the TRAD or PMIN shoes while tibialis anterior RMS amplitudes were higher in the PMIN shoes (p = .005) than either the TRAD or MAX shoes. Consistent with previous findings, these results suggest there are small differences in kinematics when running in these three shoe types. This may partly be explained by the changes in muscle activity, which may be a response in order to maintain a preferred or habitual movement path. Implications for these difference in muscle activity in terms of fatigue or injury remain to be determined.
... There are also significant differences in knee kinematics, peak ground reaction forces, joint movements and joint power trajectories (Riley et al., 2008). Treadmill running elicits weaker amplitudes of soleus neuromuscular activity during the push-off phase of running than does over-ground running (Baur, Hirschmüller, Müller, Gollhofer, & Mayer, 2007). That is, the environmental context of exercise shapes its likely biomechanical properties; in this case, the mechanics of treadmill running cannot be simply generalised to the over-ground running typical of green exercise (Sinclair et al., 2013). ...
... Plantar pressure, temporalspatial kinematic and kinetic measurements have been widely used as metrics of overall running performance. For instance, spatial plantar pressure modifications have been associated with increased speed (Rosenbaum, Hautmann, Gold, & Claes, 1994), changes in muscle activity associated with treadmill and overground running (Baur, Hirschmüller, Müller, Gollhofer, & Mayer, 2007), and changes in plantar loading associated with different shod conditions during running (Wiegerinck et al., 2009). Changes in biomechanical parameters have been reported to be strongly associated with long-distance shod running in healthy participants (Degache et al., 2013;Dierks, Davis, & Hamill, 2010;Willems, De Ridder, & Roosen, 2012). ...
The aim of this systematic review was to obtain an improved insight of the present state of knowledge regarding the effect of long-distance running on gait kinetics, kinematics, spatiotemporal and foot plantar pressure. Electronic databases were searched for articles relating to biomechanical modification following long-distance running, published in English between 1990 and 2016. All the studies presenting gait parameters before and after long-distance running were included. A modified Quality Index was used for assessing methodological quality. Thirteen studies met the eligibility criteria. Five of 13 studies measured plantar pressure, reporting that the loading under the metatarsal regions were shown to be the highest following long-distance running. Ten studies reported spatiotemporal changes; step and stride frequency were generally increased, while stride length and aerial time were decreased after running. Four studies measured kinetics, indicating that vertical ground reaction force (GRF) was generally decreased, whereas impact acceleration was increased. Four studies showed that the lower limb kinematics and the foot strike techniques were altered by long-distance running. Three studies performed a second follow-up, revealing that the changes were generally returned to baseline levels. This is the first systematic review to examine the effect of long-distance running on gait kinetics, kinematics, spatiotemporal and foot plantar pressure.
... 1,11 Limitations of the study This study is not without limitations. for example, running on a treadmill creates less stress and postural adaptations 36,37 which can be modified running outdoors. although broadening these results to overground running should be done with caution, 38 the relative changes could be similar. ...
Background:
To establish whether maximalist shoes engender fewer muscular oscillations than minimalist shoes and determine to what extent these shoes, when combined with elastic compression (EC), help reduce muscle oscillations. For that purpose, we tested the effects of various levels of compression on the muscular oscillations in maximalist and minimalist footwear.
Methods:
11 volunteers executed 16 one-minute passages on a flat treadmill in a randomized order: maximalists or minimalists, walking (6 km/h) or running (10 km/h), without EC (control condition - CON) or with EC applying different pressures (9.6 mmHg, 14.5 mmHg and 20.4 mmHg). The muscular oscillations were measured on both thighs, on the rectus femoris and on the vastus medialis with tri-axial accelerometers.
Results:
Muscular oscillations are lower in maximalist shoes than in minimalist shoes, for both walking to 6 km/h and running to 10 km/h (p< 0.05). Oscillations are also reduced with EC (p< 0.05). This decrease is most marked when the pressure exercised by the EC is increased.
Conclusions:
Increased compression with minimalist shoes reduces muscular oscillations as much as maximalist shoes, when combined with lower compression.
... Treadmill running engenders lower stresses and postural adaptations (e.g. Baur et al., 2007;Milgrom et al., 2003;Nigg et al., 1995) and may not compare to running outdoors. Although broadening these results to overground running should be done with caution ( Wall and Charteris, 1980), the general patterns will be similar (e.g. ...
Minimalist running footwear has grown increasingly popular. Prior studies that have compared lower extremity biomechanics in minimalist running to traditional running conditions are largely limited to a single running velocity. This study compares the effects of running at various speeds on foot strike pattern, stride length, knee angles and ankle angles in traditional, barefoot, and minimalist running conditions. Twenty-six recreational runners (19-46 years of age) ran on a treadmill at a range of speeds (2.5-4.0 m.sec(-1)). Subjects ran with four different footwear conditions: personal, standard, and minimalist shoes and barefoot. 3D coordinates from video data were collected. The relationships between speed, knee and ankle angles at foot strike and toe-off, relative step length, and footwear conditions were evaluated by ANCOVA, with speed as the co-variate. Distribution of non-rearfoot strike was compared across shod conditions with paired t-tests. Non-rearfoot strike distribution was not significantly affected by speed, but was different between shod conditions (p < 0.05). Footwear condition and speed significantly affected ankle angle at touchdown, independent of one another (F [3,71] = 10.28, p < 0.001), with barefoot and minimalist running exhibiting greater plantarflexion at foot strike. When controlling for foot strike style, barefoot and minimalist runners exhibited greater plantarflexion than other conditions (p < 0.05). Ankle angle at lift-off and relative step length exhibited a significant interaction between speed and shod condition. Knee angles had a significant relationship with speed, but not with footwear. There is a clear influence of footwear, but not speed, on foot strike pattern. Additionally, speed and footwear predict ankle angles (greater plantarflexion at foot strike) and may have implications for minimalist runners and their risk of injury. Long-term studies utilizing various speeds and habituation times are needed.
... Regarding the Avogadro et al. (2003) study, no significant change was reported in leg stiffness or in EMG parameters in treadmill tests. However, considering that kinematics and muscle activity have been shown to differ between treadmill and overground running (Baur et al., 2007;Wank et al., 1998), further studies carried out on a track are required. ...
... Regarding the Avogadro et al. (2003) study, no significant change was reported in leg stiffness or in EMG parameters in treadmill tests. However, considering that kinematics and muscle activity have been shown to differ between treadmill and overground running (Baur et al., 2007; Wank et al., 1998), further studies carried out on a track are required. Therefore, the aim of this study was to evaluate the changes in leg-spring behavior and the concomitant EMG modifications in lower limbs during a run to exhaustion at v _ VO 2max . ...
The aim of this study was to evaluate concomitantly the changes in leg-spring behavior and
the associated modifications in the lower limb muscular activity during a constant pace run to
exhaustion at severe intensity. Methods: Twelve trained runners performed a running test at the
velocity associated with VO2max (5.1 ±0.3 m.s-1; mean time to exhaustion: 353±69 s). Running step
spatiotemporal parameters and spring-mass stiffness were calculated from vertical and horizontal
components of ground reaction force measured by a 6.40 m long force platform system. The
myoelectrical activity was measured by wireless surface electrodes on eight lower limb muscles.
Results: The leg stiffness decreased significantly (-8.9%; P<0.05) while the vertical stiffness did not
change along the exhaustive exercise. Peak vertical force (-3.5%; P<0.001) and aerial time (-9.7%;
P<0.001) decreased and contact time significantly increased (+4.6%; P<0.05). The myoelectrical
activity decreased significantly for triceps surae but neither vastus medialis nor vastus lateralis
presented significant change. Both rectus and biceps femoris increased in the early phase of swing
(+14.7%; P<0.05) and during the pre-activation phase (+16.2%; P<0.05). Conclusion: The decrease in
leg spring-stiffness associated with the decrease in peak vertical ground reaction force was consistent
with the decline in plantarflexor activity. The biarticular rectus femoris and biceps femoris seem to
play a major role in the mechanical and spatiotemporal adjustments of stride pattern with the
occurrence of fatigue during such exhaustive run.
... Age relation to touchdown (=1.0) in % of stride (Baur et al, 2007). Values below 1.0 for the onset indicate the onset of activity before touchdown and therefore preactivity (Fig. 2). ...
Gender-specific neuromuscular activity for the ankle (e.g., peroneal muscle) is currently not known. This knowledge may contribute to the understanding of overuse injury mechanisms. The purpose was therefore to analyse the neuromuscular activity of the peroneal muscle in healthy runners.
Fifty-three male and 54 female competitive runners were tested on a treadmill at 3.33 m s(-1). Neuromuscular activity of the M. peroneus longus was measured by electromyography and analysed in the time domain (onset of activation, time of maximum of activation, total time of activation) in % of stride time in relation to touchdown (=1.0). Additionally, mean amplitudes for the gait cycle phases preactivation, weight acceptance and push-off were calculated and normalised to the mean activity of the entire gait cycle.
Onset of activation (mean; female: 0.86/male: 0.90, p<0.0001) and time of maximum of activation (female: 1.13/male: 1.16, p<0.0001) occurred earlier in female compared to male and the total time of activation was longer in women (female: 0.42/male: 0.39, p=0.0036). In preactivation, women showed higher amplitudes (+21%) compared to men (female: 1.16/male: 0.92, p<0.0001). Activity during weight acceptance (female: 2.26/male: 2.41, p=0.0039) and push-off (female: 0.93/male: 1.07, p=0.0027) were higher in men.
Activation strategies of the peroneal muscle appear to be gender-specific. Higher preactivation amplitudes in females indicate a different neuromuscular control in anticipation of touchdown ("pre-programmed activity"). These data may help interpret epidemiologically reported differences between genders in overuse injury frequency and localisation.
... Dynamometry quantifies the muscular capacity in muscular recruitment, power, 1 and strength capacity during training procedures and depends on mathematical procedures to extract the correct biological information [1,2,7,14,28]. When associated with electromyography, this technique can be used to quantify muscular strength, balance, power, and recruitment, and has been successfully applied in other biomechanical studies [5,6,9,14,23,27]. ...
This study analyzes the performance of knee extension and flexion of Taekwondo and Kickboxing athletes. The power values were extracted through electromyography obtained by an isokinetic dynamometer at 60 degrees per second. These values are resulted from the square of the electromyography signal. The analysis of kick power was made using a modified wavelet algorithm considering values with 95% significance. Both groups presented equivalent power and torque capacity with different training times and experience, on the other hand, the wavelet analysis showed better results in muscular recruitment performance in athletes with more experience, in other words, power is not only performance but also power plus recruitment produces better results. This study uniquely showed that muscular enhancement capacity is not only related to the power capacity of contraction but also to motor coordination.
El objetivo del presente estudio es comprobar las diferencias en los patrones de activación muscular de la extremidad inferior entre las distintas modalidades de carrera (velocidad, medio fondo y fondo) al aire libre, observando determinados parámetros de activación muscular y espacio-temporales en las fases de contacto inicial y despegue. Se obtuvo como resultados diferencias significativas en la actividad muscular del Bíceps Femoral, en la fase de contacto inicial entre mediofondistas y fondistas (p=0,02), y en determinadas variables espaciotemporales. Los resultados muestran la existencia de diferencias en los patrones de activación muscular de la extremidad inferior y en ciertos parámetros espaciotemporales durante la carrera al aire libre.
Purpose : The purpose of this study was to compare the changes in lower extremity muscle morphology and electromyography (EMG) signals during treadmill running (TR) and plastic track running (PR). Methods : A total of 10 healthy male runners aged 22.5±1.3 years, height: 175.5±4.5 cm; weight: 71.9±2.7 kg; BMI: 22.1±1.1 volunteered to participate in this study. Muscle morphology data were collected by a portable ultrasound scanner before and after running. Median frequency (MF), mean power frequency (MPF) and root mean square (RMS) were monitored during TR and PR. Results : The results indicated that muscle thickness and pennation angle have increased after running. The muscle thickness after PR showed significantly higher than TR in tested muscle except tibialis anterior (TA) and medial gastrocnemius (MG). In contrast, only the pennation angle of TA and lateral gastrocnemius (LG) after PR was significantly different from that after TR ( P <0.001, P = 0.002). The most significant difference in the change rate of muscle thickness was found at TA. In addition, TA and MG showed significantly higher change rate of the pennation angle after TR than that after PR. Both of MF and MPF showed a downward trend after TR and PR. It could discover that the MF and MPF of LG during TR showed a significantly lower than that during PR both in two phases ( P =0.001, P <0.001). However, in the last 5 minutes, MF and MPF of MQ during PR were smaller than that during PR ( P = 0.001, P = 0.015). Furthermore, MF of RF during TR showed significantly different from that during PR ( P = 0.017). From the point of RMS, in the first five minutes, the RMS of medical quadriceps (MQ), lateral quadriceps (LQ), hamstring muscles (HM) and MG during TR was significantly higher than that of PR ( P <0.05). In addition, the RMS of all tested muscles after TR was significantly higher than after PR during the last 5 minutes ( P <0.05). Conclusions : The current study indicated that TR and PR would cause different effects to lower extremity muscle morphology. In addition, the EMG signals based on running surfaces are also unconformity. Compared with the plastic track, the treadmill will bring more stimulation to the lower extremity muscles. The preliminary findings provide further insights into the rationality of runners’ choice of the running surface.
Running is one of the most popular sport practices in the world. However, to our knowledge, none of the previous research about the characteristics of outdoor running makes a distinction between the different modalities of runners. Sixty-five healthy runners classified in sprinters, middle distance and long-distance runners performed five series of 100 metres on the synthetic outdoor track at competition pace. Muscle activity of lower limb muscles at initial contact and toe-off, involving the gluteus medius (GMED), gluteus maximus (GMAX), biceps femoris (BF), rectus femoris (RF), tiabilis anterior (TA) and medial gastrocnemius (MGAS), and spatiotemporal parameters were analysed. Sprinters showed high percentages of muscle activity at initial contact, in particular, the TA activity was the highest. The RF activity was significantly the lowest activity registered. At toe-off, sprinters showed the highest activity in all muscles analysed. Middle-distance runners had the highest activity of GMAX, BF and MGAS during the initial contact. In long-distance runners, the GMED and RF activity during the initial contact is highlighted, showing the highest activity of this phase. Different patterns of lower limb muscle activity and spatiotemporal parameters exist depending on the modality of the runner.
Total knee arthroplasty (TKA) improves the quality of life in those suffering from debilitating arthritis of the knee. However, little is known about the influence of TKA on restoring physical function. Prior studies have used artificial means, such as instrumented treadmills, to assess physical function after TKA. In this study an insole sensor device was used to quantify parameters of gait. The purpose of this study was to evaluate the ability of a wearable insole sensor device to measure immediate postoperative gait parameters at 2 weeks and 6 weeks following primary TKA and to determine if the device was suitable and sensitive enough to identify and measure potentially subtle changes in these measures at these early postoperative time periods. Twenty-nine patients with unilateral TKA, without contralateral knee pain, and aid-free walking before surgery were evaluated. An insole force sensor measured the postoperative parameters while walking a distance of 40 m on level ground at 2 and 6 weeks after TKA. The loading rate of the operated lower extremity was an average of 68.7% of the contralateral side at 2 weeks post-surgery and increased to 82.1% at 6 weeks post-surgery (p < 0.001). The mean gait speed increased from 0.75 to 1.02 m/s, (p < 0.001) and cadence increased from 82.9 to 99.9 steps/min (p < 0.001), while the numeric pain scale at rest decreased from 3.5/10 to 2.2/10, (p < 0.001) and the pain while walking from 3.9/10 to 2.4/10, (p < 0.001) from 2 to 6 weeks post-surgery. A significant improvement in gait parameters is detectable in the first 6 weeks after surgery with the use of a wearable insole device. As the gait speed and cadence increase and the VAS pain level decreases, the loading rate and average peak force begin to normalize. This device may allow for early gait analysis and have potential clinical utility in detecting early differences in patients' functional status following TKA.
Context:
Motorized treadmills (MT) present an altered motor task compared to overground (OG) locomotion in that MT belt surfaces are motor-driven, whereas individuals walking/running OG must propel themselves. A possible solution may lie with novel non-motorized treadmill (NMT) devices as the belt surface is propelled by the user.
Objective:
The purpose of this study was to compare gait performance during both MT and NMT locomotion to OG.
Design:
Crossover study.
Setting:
A university research laboratory.
Patients:
Twenty healthy adults (10 women) participated in the study.
Intervention:
Each participant performed self-selected walking and running OG, and on both an MT and NMT.
Main outcome measure:
Shoulder, trunk and lower-extremity kinematics were analyzed for each treadmill condition and compared to OG.
Results:
The analyses demonstrated that there were no differences between MT and OG gait kinematics during either walking or running. However, NMT gait showed increased hip, knee and ankle flexion in late swing and early stance compared to OG during both walking and running. For example, during walking the NMT elicited hip, knee and ankle F/E angles of 34.7 deg, 8.0 deg and 3.6 deg at foot strike compared to 24.8 deg, -3.1 deg and -5.8 deg in the OG condition (P < 0.05). There was also a significant reduction in trunk F/E RoM during running compared to OG (7.7 deg in NMT vs. 9.8 deg in OG).
Conclusions:
These differences may have implications for both training and rehabilitation on an NMT. Future studies should consider the influence of NMT familiarization on gait performance, and should emphasize the assessment of neuromuscular performance.
Steeds meer mensen doen aan hardlopen, ‘gewoon’ over de vaste grond (doorgaans buiten) of op een loopband (doorgaans binnen). Zijn deze beide manieren van hardlopen vergelijkbaar? En zo ja, in hoeverre geldt dit dan ook voor enkele speciale loopbanden die tegenwoordig op de markt zijn?
Achilles tendinopathy is a common injury in running sports however the exact etiology of Achilles injury is still unclear. In recent years, altered neuromotor recruitment patterns of the triceps surae have been hypothesized to create differential intra-tendinous loads leading to pathology; however, this hypothesis has not been investigated. Further, the effect foot orthoses may have on neuromotor recruitment of the triceps surae in Achilles tendinopathy has not been investigated. Methods: The electromyographic activity of the triceps surae was recorded during an over-ground running task. Fifteen Achilles injured participants and 19 asymptomatic controls were assessed in a footwear only condition. The Achilles injured participants were also assessed running in a pre-fabricated foot orthoses. Results: In Achilles injured participants, there was a significant difference between soleus and lateral gastrocnemius offset times during running compared to the asymptomatic controls (p<0.05). There were no significant differences in triceps surae muscle activity between the footwear only and footwear and orthoses condition in the Achilles injured participants. Conclusions: The finding that triceps surae activity is altered in participants with Achilles tendinopathy may have clinical importance as it suggests that intra-tendinous loads are altered which may contribute to pathological changes. Further, foot orthoses have no immediate effect on the neuromotor control of the triceps surae.
HIGH-SPEED TREADMILLS HAVE BECOME VALUABLE TOOLS FOR INCREASING SPEED AND SPORTS PERFORMANCE OVER THE PAST 2 DECADES. TRADITIONALLY, THEY HAVE BEEN PART OF NARROWLY FOCUSED CLINIC-BASED PROGRAMS DESIGNED TO INCREASE SPEED SOLELY WITH THE USE OF TECHNOLOGY. THIS HAS LED TO QUESTIONS ABOUT SURFACE TRANSFER, HIGH INJURY RATES, AND HOW THIS TECHNOLOGY FITS INTO A COMPREHENSIVE STRENGTH AND CONDITIONING PROGRAM. HERE, WE WILL NOT ONLY ADDRESS THESE ISSUES BUT ALSO DEMONSTRATE THAT WHEN PROPERLY INTEGRATED, HIGH-SPEED TREADMILLS ARE EXCEPTIONAL TOOLS THAT CAN BE USED IN A VARIETY OF SETTINGS TO IMPROVE PERFORMANCE FOR THE SPEED AND POWER ATHLETES WHILE ALL BUT ELIMINATING SPRINT-RELATED INJURIES.
Running on a road, for fitness, sport, or recreation, poses unique challenges to the runner, one of which is the camber of the surface. Few studies have examined the effects of camber on running, namely kinematic studies of the knee and ankle. There is currently no information available regarding muscle response to running on a cambered road surface. The purpose of this study was to investigate the effects of a cambered road on lower extremity muscle activity, as measured by electromyography in recreational runners. In addition, this study examined a true outdoor road surface, as opposed to a treadmill surface. The mean muscle activity of the tibialis anterior (TA), lateral gastrocnemius (LG), vastus medialis oblique (VMO), biceps femoris (BF), and gluteus medius (GM) were studied. Fifteen runners completed multiple running trials on cambered and level surfaces. During the stance phase, mean TA, LG, and VMO activity were greater on the gutter side than the crown side. There were no differences in mean muscle activity during the swing phase. The findings of this study suggest that running on a road camber alters the activity of select lower extremity muscles possibly in response to lower extremity compensations to the cambered condition.
Running is the most important discipline for Olympic triathlon success. However, cycling impairs running muscle recruitment and performance in some highly trained triathletes; though it is not known if this occurs in elite international triathletes. The purpose of this study was to investigate the effect of cycling in two different protocols on running economy and neuromuscular control in elite international triathletes. Muscle recruitment and sagittal plane joint angles of the left lower extremity and running economy were compared between control (no preceding cycle) and transition (preceded by cycling) runs for two different cycle protocols (20-minute low-intensity and 50-minute high-intensity cycles) in seven elite international triathletes. Muscle recruitment and joint angles were not different between control and transition runs for either cycle protocols. Running economy was also not different between control and transition runs for the low-intensity (62.4 +/- 4.5 vs. 62.1 +/- 4.0 ml/min/kg, p > 0.05) and high-intensity (63.4 +/- 3.5 vs. 63.3 +/- 4.3 ml/min/kg, p > 0.05) cycle protocols. The results of this study demonstrate that both low- and high-intensity cycles do not adversely influence neuromuscular control and running economy in elite international triathletes.
Cinematography was used to biomechanically compare individually selected overground jogging and running velocities with equated treadmill jogging and running by adult males and females. All subjects were regular joggers but not competitive track or cross-country runners. No significant differences were recorded in stride length, stride rate, support time or non-support time for males or females when jogging at velocities of between 3.33 and 4.78 m/s (x = 3.70) or 3.45 and 4.80 m/s (x=3.97) respectively. However, it was demonstrated that at velocities of 4.82 - 6.2 m/s for males (x - 5.41) and 4.85 - 5.76 m/s for females (x = 5.29) significant differences did occur between overground and treadmill running. For both males and females stride length decreased, stride rate increased, and the period of non-support was also significantly less when running on a treadmill as compared to running overground.
When running indoors on a treadmill, the lack of air resistance results in a lower energy cost compared with running outdoors at the same velocity. A slight incline of the treadmill gradient can be used to increase the energy cost in compensation. The aim of this study was to determine the treadmill gradient that most accurately reflects the energy cost of outdoor running. Nine trained male runners, thoroughly habituated to treadmill running, ran for 6 min at six different velocities (2.92, 3.33, 3.75, 4.17, 4.58 and 5.0 m s-1) with 6 min recovery between runs. This routine was repeated six times, five times on a treadmill set at different grades (0%, 0%, 1%, 2%, 3%) and once outdoors along a level road. Duplicate collections of expired air were taken during the final 2 min of each run to determine oxygen consumption. The repeatability of the methodology was confirmed by high correlations (r = 0.99) and non-significant differences between the duplicate expired air collections and between the repeated runs at 0% grade. The relationship between oxygen uptake (VO2) and velocity for each grade was highly linear (r > 0.99). At the two lowest velocities, VO2 during road running was not significantly different from treadmill running at 0% or 1% grade, but was significantly less than 2% and 3% grade. For 3.75 m s-1, the VO2 during road running was significantly different from treadmill running at 0%, 2% and 3% grades but not from 1% grade. For 4.17 and 4.58 m s-1, the VO2 during road running was not significantly different from that at 1% or 2% grade but was significantly greater than 0% grade and significantly less than 3% grade. At 5.0 m s-1, the VO2 for road running fell between the VO2 value for 1% and 2% grade treadmill running but was not significantly different from any of the treadmill grade conditions. This study demonstrates equality of the energetic cost of treadmill and outdoor running with the use of a 1% treadmill grade over a duration of approximately 5 min and at velocities between 2.92 and 5.0 m s-1.
Gait analysis on the treadmill and in the overground condition is used both in scientific approaches for investigating the neuronal organisation and ontogenetic development of locomotion and in a variety of clinical applications. We investigated the differences between overground and treadmill locomotion (at identical gait velocity) in 12 adults and 14 children (6-7 years old). During treadmill locomotion the step frequency increased by 7% in adults and 10% in children compared to overground walking, whereas the stride length and the stance phase of the walking cycle decreased. The swing phase, however, increased significantly by 5% in adults and remained unchanged in children. Balance-related gait parameters such as the step width and foot rotation angles increased during treadmill locomotion. The reduction of the step length was found to be stable after 10 min of treadmill walking in most subjects. With regard to the shifted phases of the walking cycle and the changed balance related gait parameters in the treadmill condition, we assume a different modulation of the central pattern generator in treadmill walking, due to a changed afferent input. Regarding the pronounced differences between overground and treadmill walking in children, it is discussed whether the systems generating and integrating different modulations of locomotion into a stable movement pattern have reached full capacity in 6-7 year old children.
The aim of the present study was to examine the physiological and mechanical factors which may be concerned in the increase in energy cost during running in a fatigued state. A group of 15 trained triathletes ran on a treadmill at velocities corresponding to their personal records over 3000m [mean 4.53 (SD 0.28) m x s(-1)] until they felt exhausted. The energy cost of running (CR) was quantified from the net O2 uptake and the elevation of blood lactate concentration. Gas exchange was measured over 1 min firstly during the 3rd-4th min and secondly during the last minute of the run. Blood samples were collected before and after the completion of the run. Mechanical changes of the centre of mass were quantified using a kinematic arm. A significant mean increase [6.9 (SD 3.5)%, P < 0.001] in CR from a mean of 4.4 (SD 0.4) J x kg(-1) x m(-1) to a mean of 4.7 (SD 0.4) J x kg(-1) x m(-1) was observed. The increase in the O2 demand of the respiratory muscles estimated from the increase in ventilation accounted for a considerable proportion [mean 25.2 (SD 10.4)%] of the increase in CR. A mean increase [17.0 (SD 26.0)%, P < 0.05] in the mechanical cost (CM) from a mean of 2.36 (SD 0.23) J x kg m(-1) to a mean of 2.74 (SD 0.55) J x kg(-1) x m(-1) was also noted. A significant correlation was found between CR and CM in the non-fatigued state (r=0.68, P < 0.01), but not in the fatigued state (r=0.25, NS). Furthermore, no correlations were found between the changes (from non-fatigued to fatigued state) in CR and the changes in CM suggesting that the increase in CR is not solely dependent on the external work done per unit of distance. Since step frequency decreased slightly in the fatigued state, the internal work would have tended to decrease slightly which would not be compatible with an increase in CR. A stepwise regressions showed that the changes in CR were linked (r=0.77, P < 0.01) to the changes in the variability of step frequency and in the variability of potential cost suggesting that a large proportion of the increase in CR was due to an increase in the step variability. The underlying mechanisms of the relationship between CR and step variability remains unclear.
This study quantified the relationships between local dynamic stabiliht and variabilitr during continuous overground and treadmill walking. Stride-to-stride standard deviations were computed from temporal and kinematic data. Marimum finite-time Lyapunov exponents were estimated to quantify local dynamic stability. Local stability of gait kinematics was shown to be achieved over multiple consecutive strides. Traditional measures of variability poorly predicted local stability. Treadmill walking was associated with significant changes in both variability and local stability. Thus, motorized treadmills may produce misleading or erroneous results in situations where changes in neuromuscular control are likely to affect the variability and/or stability of locomotion.
As part of a comprehensive occupational medical program for fire departments in the USA, the National Fire Protection Association and The Fire Service Joint Labor Management Wellness/Fitness Initiative endorse a standardized submaximal test that uses the Gerkin treadmill protocol for predicting the maximal oxygen uptake (VO(2max)) of firefighters.
To test the validity of the Gerkin treadmill protocol in healthy men and women.
Fifty-four healthy men and women (age range 19-58 years) performed the Gerkin test and a treadmill run test to maximal exhaustion. Their heart rates were monitored continuously with an electrocardiogram during each test. During the VO(2max) test, the subjects' VO(2) was measured continuously using indirect calorimetry.
Although the predicted and observed VO(2max) values correlated (r = 0.70, P < 0.001 and standard error of estimate = 5.98 ml/kg/min), the mean values differed (49.8 +/- 8.3 and 41.8 +/- 5.8 ml/kg/min, respectively) (P < 0.001). The VO(2max) value was overestimated in 50 (93%) participants. The overestimation was >25% in 18 (33%) participants. Gender, age and VO(2max) did not affect the Gerkin protocol's predictability of VO(2max).
The Gerkin treadmill protocol overpredicts VO(2max) in healthy men and women and, therefore, should not be used for predicting VO(2max) in individual firefighters, particularly if VO(2max) is a criterion for inclusion or exclusion from duty. At this time, a valid treadmill running test is needed for predicting the VO(2max) value of individual firefighters.
To compare treadmill and shuttle walk tests for assessing functional capacity in patients with intermittent claudication, with respect to test-retest reliability, cardiovascular responses, and patient preferences.
Patients with stable intermittent claudication (N = 55, ages 52-85 yr, median age 68 yr) were recruited from the Sheffield Vascular Institute at the Northern General Hospital, Sheffield, UK. Each patient performed an incremental shuttle walk test, a constant-pace shuttle walk test, and a standardized treadmill test (3.2 km x h(-1), 12% gradient), each on three occasions. The incremental shuttle walk began at 3 km x h(-1) and increased by 0.5 km x h(-1) every minute, whereas the constant-pace shuttle walk was performed at the fixed pace of 4 km x h(-1). Claudication distance (CD), maximum walking distance (MWD), heart rate (HR), and blood pressure were assessed in each testing session. The patients also completed a test preference questionnaire.
CD and MWD for both shuttle walks were greater than the corresponding walking distances achieved in the treadmill test (P < 0.001). Average coefficients of variation for repeated incremental shuttle walk, constant-pace shuttle walk, and treadmill tests were 15.9%, 21.1%, and 18.7%, respectively, for MWD, corresponding to average intraclass correlation coefficients of 0.87, 0.82, and 0.87. Treadmill walking evoked greater increases in HR and blood pressure (P < 0.001), and fewer patients expressed a preference for it (24 vs 43% for shuttle walking).
These findings indicated that shuttle walk testing exhibits similar test-retest reliability as treadmill testing, but that it evoked a lower level of cardiovascular stress and is preferred to treadmill testing by a large proportion of patients.
Our current knowledge on interactions between runner and runningshoe is mainly based on treadmill measurements. In order to reveal stress load and adaptation on playing surfaces it was necessary to develop a combined measuring device out of 3-D video motion analysis and portable pressure measurement system. By means of a motor driven cart moving parallel to the subject with comparable position of cameras to the treadmill test it was possible to set up an identical trial for track and field. 12 subjects (male, age 24-32, size 9) were tested at a speed of 2.8 m/s. The varying conditions were treadmill and grass and two different constructed running shoes. 200 cycles and over 1000 steps were analyzed. The quantitative analysis of 37 parameters describing the contact phase was performed using the wilcoxon test for paired samples.-A qualitative comparison of running styles was introduced by using angle-angle-diagrams (knee and ankle by 3-D data) similar to those first described for 2-D by P.R. Cavanagh in 1973. It showed a huge interindividual variability under same conditions. Comparing the angle-angle-diagrams for the four different running conditions it was possible to classify them into three characteristic groups: non-adaptors, surface-adaptors and shoe-adaptors. Comparing track and field to treadmill measurements significant differences were found for the knee at impact: On treadmill the initial knee angle was 4.6 degrees more extended at a 13% higher angle velocity and a 30% higher angle deceleration (sig. p less than 0.05). A 7.3% higher impulse was found on grass at a 5.9% higher step length. No difference in maximum pressure was found. These results show that adaptation is performed mainly by the knee. Changing the motion pattern the knee seems to be capable of homogenizing the different stress loads to the foot. Comparing the running shoes significant differences were found in the motion of the ankle: a controversial behaviour was found to be on treadmill and grass. The pressure data revealed significant differences for the treadmill test to be in the heel area, for grass in the arch area. This points to an--up to now--unknown importance of the arch on unplain surfaces that are obviously influenced by the construction of the shoe and are not accessible by treadmill tests. The described different behaviour of shoes in treadmill and track and field tests points out the reduced validity of single treadmill tests.(ABSTRACT TRUNCATED AT 400 WORDS)
Within a set of repeated measurements, 12 male subjects performed the following types of muscle contraction: (1) running at constant velocity (12 km.h-1); (2) one-leg hopping at the frequency preferred; (3) both-legs hopping at the frequency preferred; (4) drop jumps from a height of 0.40 m. The surface electromyographs (EMG) from the left and right legs were recorded, together with the averaged signals from vertical ground reaction forces and angular displacement of the ankle joint. Reliability coefficients for the day to day and the week to week comparison were calculated. In addition, on any one test day the positions of the electrodes were systematically changed. The analysis of various EMG parameters (integrated-EMG) revealed high coefficients for both comparisons as well as for the total set of measurements. Qualitative comparisons of the EMG showed a high reproducibility of the shape of the patterns. If the relative position of the electrodes with respect to the belly of the muscle is changed, the amplitudes of the EMG recordings are markedly reduced. It is concluded that surface EMG is a reliable method for studies of the neuromuscular system. On the basis of the data presented, it is suggested that the term "reliability" should be replaced by the term "reproducibility" in order to cover both the aspect of the relative stability plus the aspects of linear changes and the scattering of the data in repeated measurements.
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.
A descriptive comparative study was done to validate the use of the treadmill as an experimental device to investigate the electromyographic (EMG) signal during human locomotion. Eight subjects walked on a walkway and on a treadmill and EMG recordings of several consecutive strides were made during each procedure. These recordings were made from the soleus, rectus femoris, biceps femoris, vastus medialis and tibialis anterior muscles. By using the correlation coefficient and the value of the slope of the regression line resulting from correlating the linear envelopes (digitized at 50 Hz) of EMG activity from the two walk modes, it was shown that similar profiles of EMG activity exist between the walkway and treadmill. This was so for most muscles investigated with one exception, the biceps femoris. Furthermore, there was a tendency for the treadmill data to indicate slightly larger EMG amplitudes, but lower variation, than did the walkway data. However, in view of the overall similarity of the profiles obtained from both conditions, it is concluded that the treadmill is a valid laboratory instrument to study gait.
Repeatability is an important consideration for gait analysis data that are being used as an adjunct to clinical decision making. An index of repeatability may be based on a statistical criterion (variance ratio) that reflects similarity of wave forms over a number of identical cycles. The purpose of this study was to use the variance ratio to assess the repeatability of phasic muscle activity recorded with surface and bipolar intramuscular wire electrodes during gait on 10 normal subjects. Variance ratios were calculated using rectified and smoothed electromyographic data recorded simultaneously from the two types of electrodes. Three measures of repeatability (reproducibility, reliability, and constancy--defined as the cycle-to-cycle, run-to-run, and day-to-day repeatability of phasic muscle activity) were used to compare the performance of the two electrode techniques. Results show that the reproducibility and reliability were better for surface electrodes than for intramuscular wire electrodes, and constancy was good for surface electrodes and poor for intramuscular wire electrodes. Repeatability improved with increasing smoothing window lengths but was better for surface electrodes than wire electrodes, irrespective of the smoothing window. This study indicates that surface electrode data represent a more consistent measure of activity of superficial muscles, if comparisons are to be made between gait data from different test days.
Onset of firing for the quadriceps, hamstrings, and gastroc soleus groups during running, both on a treadmill and over ground, was determined in seven normal adult male subjects. Surface and wire electrode data were collected simultaneously from 959 individual gait cycles. The mean velocity over ground was 274 +/- 38 m/minute, with a mean cadence of 171 +/- 14 steps/minute. The treadmill was set at 107 m/minute (4 miles/hour), and the subjects' mean cadence was 147 +/- 11 steps/minute. Over ground, the mean swing/stance ratio was 70/30 +/- 3%, and that for the treadmill was 60/40 +/- 6%. Like muscle groups on the right and left showed a mean difference in onset of muscle activity of 1.3% (+/- 4.6%) when measured during a minimum of ten cycles per subject for each test condition. The average difference in time of onset between the surface and wire electrodes was 2% (SD +/- 4.9%) on the treadmill and 1.5% (SD +/- 3.7%) for over-ground running. These differences are not statistically significant. Surface and wire electrode data have been determined to be equivalent only for regional synergistic muscle groups and should not be extrapolated to compare functions of individual muscles within those groups.
The purpose of this study was to determine whether walking on a treadmill is a valid simulator of overground walking with respect to rearfoot motion. The tibial, calcaneal, and rearfoot motions of 10 subjects (2 males, 8 females) were videotaped while they walked on a treadmill and overground. The results of a series of t-tests showed that there was no statistically significant difference between the two conditions on any of the variables measured.
Treadmills are often used in research projects to simulate overground locomotion, assuming that locomotion is similar on a treadmill and overground. The purpose of this investigation was to determine whether a treadmill could be used to simulate overground locomotion. Twenty-two subjects ran on four different surfaces: overground and three treadmills that differed in size and power. The kinematics of the right leg and foot were studied using two high-speed Locam cameras (lateral and posterior view). The subjects ran in two different shoes at four different speeds (3.0-6.0 m.s-1). The differences in the kinematics between treadmill and overground running could be divided into systematic and subject dependent components. Subjects systematically planted their feet in a flatter position on the treadmill than overground. Most of the lower extremity kinematic variables, however, showed inconsistent trends for individual subjects, depending on the individual subject's running style, running speed, and shoe/treadmill situation. The differences were substantial. It is not yet understood how the human locomotor system adapts to a particular treadmill running situation. However, it is concluded that individual assessment of running kinematics on a treadmill for shoe or shoe orthotic assessment may possibly lead to inadequate conclusions about overground running.
Ten uninjured subjects (ages 18 to 30 years) had electromyographic testing of the peroneus longus, peroneus brevis, and tibialis anterior muscles in response to inversion moments at two speeds (50 and 200 deg/sec) and two joint angles (neutral and 20 degrees of plantar flexion) using a hydraulically controlled tilt platform. Subjects underwent 10 trials of each type of inversion moment on Day 1 testing, which included both legs. On Day 2, subjects again underwent 10 trials of each type of inversion moment, but only on one leg. Reliability was assessed by comparing left and right leg data within muscle groups for Day 1 testing. Repeatability was assessed by comparing Day 1 with Day 2 data. The latency measurements (the time between the beginning of the inversion moment and the onset of first motor response) for the peroneus brevis and tibialis anterior muscles were found to be reliable and repeatable with no significant differences between the same muscle groups. The peroneus longus muscle had a significant difference between legs but was found to be highly repeatable. Speed of inversion moment and plantar flexion angle both caused significant changes in latency response of the peroneus muscles, with increased speed producing a shorter latency response and increased angle causing a longer latency response. Our results indicate a loss of protective reflexes with increasing plantar flexion.
Relationships between running economy (RE; submaximal VO(2) for a given running speed) and the temporal EMG characteristics of bi-articular leg muscles were quantified in a group of well-trained runners. Nine subjects completed three test sessions: a determination of maximal aerobic demand (VO(2)max); an accommodation session at the experimental speed of 4.13 m.s(-1) and a session during which EMG and RE data were collected simultaneously at the experimental speed of 4.13 m.s(-1) Measures of muscle onset, on-time durations, and on-time coactivation durations were calculated from the following muscles: rectus femoris, medial hamstrings, lateral hamstrings, and gastrocnemius. Nonparametric correlations between RE and EMG characteristics displayed both positive and negative relationships and exhibited a wide range of values. Two EMG measures were significantly correlated (r > 0.67) with RE. Earlier onset of rectus femoris during swing phase and a shorter duration of hamstring - gastrocnemius coactivation during swing were associated with more economical runners. Although not statistically significant, correlation coefficients calculated for measures of coactivation during stance and RE ranged from -0.42 to -0.65. This trend indicates that individuals who exhibited a greater amount of coactivation between bi-articular muscles during the stance phase of the running cycle tended to be more economical. These relationships suggest different activation patterns in bi-articular muscles between economical and uneconomical runners.
The use of linear envelopes to represent the electromyographic (EMG) measurements obtained during locomotion has become common practice. Guidelines for designing envelope filters and specifying the minimum number of strides needed to produce valid EMG profiles have been developed. Electromyograms from eight major muscles of the lower leg are measured from five normal young adults during self-selected slow, free and fast walking speeds. 30 strides per task are measured. The 'ideal' EMG profile is defined from the ensemble average of the rectified EMG signal. An error measure is defined and used as a criterion to assess the appropriateness of various cut-off frequencies for envelope filters and the number of strides required for establishing a good EMG profile. It is found that between six and ten strides are needed to form a representative profile, and an envelope filter with a minimum cut-off frequency of approximately 9 Hz is necessary.
Treadmills are often used in research to analyse kinematic and physiological variables. The success of transfering the results to overground running depends on the comparability of the values between the two situations. The aim of the present study was to compare the kinematics and muscle activities in overground and treadmill running. Ten male physical education students with experience in treadmill running were asked to run with a speed of 4.0 and 6.0 m/s both overground and on a Woodway treadmill. The 3D-kinematics of the limbs were studied using a two camera video tracking system. Additionally the surface EMG of six lower limb muscles and the pattern of ground contact of the right foot was registered. Both the activities of the leg muscles and several kinematic variables showed systematic changes from overground to treadmill running. On the treadmill the subjects favoured a type of running that provided them with a higher level of security. The swing amplitude of the leg, the vertical displacement and the variance in vertical and horizontal velocity were lower in treadmill running. The angle between shoe sole and ground at foot impact was also lower and the forward lean of the upper body was higher in running on the treadmill compared with the overground mode. Most of the subjects reduced their step length and increased stride frequency in treadmill running. Furthermore, the contact time in treadmill running was shorter than for overground running. The above mentioned kinematic variables were significantly different (p < 0.05). The EMG patterns of the leg muscles were generally similar between overground and treadmill modes, but some minor differences could consistently be identified.
This review article summarizes the current literature regarding the analysis of running gait. It is compared to walking and sprinting. The current state of knowledge is presented as it fits in the context of the history of analysis of movement. The characteristics of the gait cycle and its relationship to potential and kinetic energy interactions are reviewed. The timing of electromyographic activity is provided. Kinematic and kinetic data (including center of pressure measurements, raw force plate data, joint moments, and joint powers) and the impact of changes in velocity on these findings is presented. The status of shoewear literature, alterations in movement strategies, the role of biarticular muscles, and the springlike function of tendons are addressed. This type of information can provide insight into injury mechanisms and training strategies. Copyright 1998 Elsevier Science B.V.
We studied the familiarisation time required for reliable sagittal-plane knee kinematics and temporal-distance gait measurements to be obtained from treadmill walking. We also studied whether knee kinematics and temporal-distance gait measurements obtained from familiarised treadmill walking can be generalised to overground walking. Sixteen subjects without pathology walked on a level overground walkway and on a treadmill. A motion measurement system was used to measure sagittal plane knee movements and temporal-distance gait parameters during overground and treadmill walking. Highly reliable knee kinematics and temporal-distance gait measurements [intraclass correlation coefficient (ICC)(2,1)>/=0.93] were found after 6 min of treadmill walking. These measurements, obtained after 6 min of treadmill walking, were highly correlated with and not significantly different to those of overground walking. Reliable measurements that can be generalised to overground walking, can be obtained from the treadmill within a familiarisation time of 6 min.
A basic aspect of the neuronal control of quadrupedal locomotion of cat and of bipedal stance and gait of humans concerns the antigravity function of leg extensors. In humans proprioceptive reflexes involved in the maintenance of body equilibrium depend on the presence of contact forces opposing gravity. Extensor load receptors are thought to signal changes of the projection of body's centre of mass with respect to the feet. According to observations in the cat, this afferent input probably arises from Golgi tendon organs and represents a newly discovered function of these receptors in the regulation of stance and gait. From these experiments it can be concluded that during locomotion there is a closing of Ib inhibitory and an opening of Ib extensor facilitatory paths. In humans evidence for a significant contribution of load receptor contribution to the leg muscle activation came from immersion experiments. Compensatory leg muscle activation depends on the actual body weight. Also during gait the strength of leg extensor activation during the stance phase is load dependent. In patients with Parkinson's disease there is a reduced load sensitivity and decreased leg extensor activation, which might contribute to the movement disorder. Recent experiments in paraplegic patients show that the beneficial effects of a locomotor training critically depends on the initial degree of body unloading and reloading during the course of the training period.
The purpose of this study was to quantify effects of shoe sole modification on skeletal kinematics of the calcaneus and tibia during the stance phase of running.
Intracortical bone pins with reflective marker triads were inserted under standard local anesthetic into the calcaneus and tibia of five healthy male subjects. The three-dimensional tibiocalcaneal rotations were determined using a joint coordinate system approach. Three shoe sole modifications were tested with different sole geometry: a lateral heel flare of 25 degrees (flared), no flare 0 degrees (straight), and a rounded sole.
The results showed that these shoe sole modifications did not change tibiocalcaneal rotations substantially. The shoe sole effects at the bone level were small and unsystematic (mean effects being less than 1 degrees ) compared with the differences between the subjects (up to 7 degrees ). Shoe eversion measured simultaneously with shoe markers showed no systematic shoe sole effects. A comparison of shoe and bone results showed the total shoe eversion and maximum shoe eversion velocity to be approximately twice as large as the respective measurements based on bone markers (correlations being r = 0.79 for maximum eversion velocity; r = 0.88 for total eversion), indicating that there may be a relationship or coupling effect between the shoes and the bone.
It is concluded that the tibiocalcaneal kinematics of running may be individually unique and that shoe sole modifications may not be able to change them substantially.
Objective. To compare overground and treadmill ambulation for possible differences in gait temporal variables and leg joint kinematics. Design. A human subject trial of walking in two conditions. Background. The treadmill is frequently used to simulate overground ambulation; however, the literature shows a wide difference of opinion as to whether the treadmill replicates the overground environment. Methods. A total of 17 uninjured subjects walked overground at their preferred velocity. The treadmill was then set at the average velocity obtained in overground walking. Gait temporal variables and leg joint kinematics were analysed using the three dimensional (3D) Kinemetrix Motion Analysis System. The data were analysed separately for the two gender groups and for the groups combined. Results. In the females, only the maximum hip flexion angle was significantly different in the two conditions with greater flexion occurring on the treadmill. For males, significant differences were noted between the two conditions for cadence and maximum knee flexion angle with greater values in the treadmill walking. When all subjects were compared, significant increases were seen during treadmill walking in hip range of motion, maximum hip flexion joint angle and cadence, while a significant decrease was observed in stance time. Conclusions. Statistically significant differences exist between overground and treadmill walking in healthy subjects for some joint kinematic and temporal variables.
Objective:
To compare overground and treadmill running for differences in the three-dimensional angular kinematics of the lumbo-pelvic-hip complex.
Design:
A within-subject repeated measures design.
Background:
The treadmill is an attractive research instrument as speed and slope are easily controlled and the required calibration volume is reduced. However, the degree to which treadmill running simulates overground running has not been resolved in the literature to date.
Methods:
10 able-bodied subjects ran overground and on a treadmill at a self-selected speed. The treadmill speed was matched to each subjects respective average overground speed. The time-distance and the three-dimensional angular kinematic data were captured using a passive marker based motion analysis system. A set of angular and temporal kinematic parameters were extracted from the data and subjected to statistical analyses.
Results:
Significant differences were found between overground and treadmill running for all the time-distance parameters. Despite this, the kinematics of the lumbar spine and pelvis were similar between the two running conditions, with only three parameters being significantly different. These were lumbar extension at initial contact, anterior pelvic tilt at initial contact and the first maximum anterior pelvic tilt. Hip flexion-extension parameters were also only found to display subtle differences. Of the 17 hip parameters analysed, only hip flexion at initial contact, maximum hip flexion at loading response, hip extension at toe off, maximum hip extension and hip flexion-extension range of motion were found to be significantly different.
Conclusion:
A high powered treadmill with a minimal belt speed fluctuation is capable of being used to obtain a representation of the typical three-dimensional kinematic pattern of the lumbo-pelvic-hip complex during running.
Relevance:
In order for the treadmill to be accepted as a useful research and/or clinical assessment instrument, it must be demonstrated that it does not significantly alter the performance of the evaluated activity. In this respect, a treadmill with minimal intra-stride belt speed variability and similar surface stiffness to the relevant overground condition is likely to be capable of being used to obtain a representation of the typical human running action for well accommodated subjects.
Hemiparetic gait is characterized by high stride-cycle variability, diminished stance time, single-limb stance time, and stance/swing ratio in the paretic limb. Recent studies suggest treadmill (TM) training may improve the motor control underlying these variables, but supporting evidence is sparse.
This study compared gait patterns of untrained chronic hemiparetic stroke patients (n = 18; mean, 39.5 months poststroke) during overground (OG) and TM walking at matched velocities. Variables included relative stance time, relative single-limb stance time, stance/swing ratio, peak force, and impulse. Within-subject variability of these measures (CV) was used to assess gait pattern stability.
OG and TM cycle durations were similar, but CVs differed (TM < OG, p < 0.05). In the paretic limb, differences were seen in relative stance time, relative single-limb stance time, and stance/swing ratio, respectively (TM > OG, p < 0.05). These variables decreased in the nonparetic limb during TM walking (p < 0.05 for all). Improved interlimb symmetry and coordination were evidenced by decreased between-limb differences and improved relative temporal phasing, respectively, in the TM condition (p < 0.05).
Collectively, these results demonstrate that the TM induces an immediate alteration toward a more consistent and symmetric gait pattern. Further investigation is needed to determine whether TM training leads to motor relearning and neuroplasticity in chronic hemiparetic subjects.
To determine the differences between angular oscillation curves of the lumbar spine and pelvis during walkway and treadmill ambulation.
An in vivo observation of walking in overground and treadmill conditions.
Angular movements of the lumbar spine and pelvis have been obtained during overground and treadmill walking. No data are available to indicate whether lumbar spine treadmill findings may be compared or generalized to overground readings.
Nine male subjects walked at their natural cadence along an 8 m walkway positioned over a motorized treadmill. During each of 20 walking trials, kinematic data of one full gait cycle were collected in the middle segment of the walkway. Following the overground readings the walkway was removed and treadmill recordings were taken at the subjects' preferred walking speed and at an imposed speed of 1.25 m/s. Movement patterns and maximum oscillation angles were calculated in each plane.
Cross-correlation values of pairwise comparisons demonstrated almost comparable movement patterns between walking conditions (r > or =0.891; p<0.001) except for the movement in the sagittal plane (r=0.642, p<0.01). ANOVA for repeated measures revealed significant (p<0.05) differences in the gait cycle duration as well as reductions in oscillation amplitudes of the upper lumbar region and the pelvis in both the frontal and transverse plane during treadmill walking compared to walkway locomotion.
Statistically significant differences exist for some angular lumbar spine movement parameters between walkway and treadmill locomotion.
The observed differences between overground and treadmill locomotion should be taken in account when treadmill-based lumbar spine and pelvis kinematics want to be extended or compared to overground recordings.
Heart rate (HR) is widely used to adjust exercise intensity in aerobic training. Training HR recommendations are calculated often from simple equations. Because at lactate steady state (LASS) may be an intensity of exercise eliciting similar objective measures of intensity and similar subjective measures of metabolism, it is an appropriate intensity upon which to base aerobic-training prescription. The purpose of this research was to develop regression equations using age and other easily accessible characteristics to estimate the HR associated with LASS (HRLASS).
The data of 7397 healthy subjects (age >or= 10 yr; 5044 male, 2353 female) with different training habits were analyzed. All participants were tested in an incremental exercise test on the treadmill until subjective exhaustion. The LASS was determined by the concept of blood lactate at the "lactate threshold" plus a net increase of 1.5 mmol.L-1. The interdependence of further characteristics was tested by stepwise multiple regression.
Age alone did not allow a precise prediction of lass=hText>HRLASS (r = 0.645 for all participants), regardless of adjustment by sex, training state, body mass, or performance characteristics using ANCOVA. Resting HR (HRrest) decreased steeply within the second life decade but not with further advancing age. The best discrete lactate-independent predictor for HRLASS was HRmax (r = 0.798). Inclusion of age and weight in the model resulted in only a small improvement of the prediction (r = 0.826). Other anthropometrical characteristics could not improve the model further.
The use of age alone seems too imprecise for exactly driven aerobic training prescriptions. A minor improvement can be achieved in this objective by use of HRmax supplemented by age using a multiple regression model.
To determine the kinematic, kinetic and EMG responses to perturbations of the foot by running in varus, neutral, and valgus-wedged shoes.
Within-subjects study comparing kinematics, kinetics and EMG while running in three different shoe conditions.
Excessive pronation has been cited as a key contributor to many types of running injuries. However, the roles of the extrinsic foot muscles (those that control motion of the foot) during the stance phase of running have not been adequately identified, which is critical to determining the relationship between pronation and injury.
Ten males ran in varus, valgus, and neutral-wedged shoes while three-dimensional kinematic and kinetic data and EMG data were collected. Surface EMG data were collected from the tibialis anterior, peroneus longus, medial and lateral gastrocnemius, and soleus. Indwelling EMG was obtained from the tibialis posterior. The net joint moment, power, and total positive and negative work was calculated in the frontal plane. EMG onset, offset, and integrated values were reported.
The maximum eversion angle, maximum inversion moment and total negative work done in the frontal plane were greatest while running in the valgus shoe and least in the varus shoe. The greater joint moment was not accompanied by changes in muscle activation patterns, although the tibialis posterior data were inconclusive in this respect.
Greater pronation leads to greater energy absorption in the foot invertor muscles and tendons. While not conclusive, the EMG data suggest that for these muscles there was not a neuromuscular adaptation to the perturbation.
When mechanical parameters of running are measured, runners have to be accustomed to testing conditions. Nevertheless, habituated runners could still show slight evolutions of their patterns at the beginning of each new running bout. This study investigated runners' stiffness adjustments during shoe and barefoot running and stiffness evolutions of shoes. Twenty-two runners performed two 4-minute bouts at 3.61 m.s-1 shod and barefoot after a 4-min warm-up period. Vertical and leg stiffness decreased during the shoe condition but remained stable in the barefoot condition, p < 0.001. Moreover, an impactor test showed that shoe stiffness increased significantly during the first 4 minutes, p < 0.001. Beyond the 4th minute, shoe properties remained stable. Even if runners were accustomed to the testing condition, as running pattern remained stable during barefoot running, they adjusted their leg and vertical stiffness during shoe running. Moreover, as measurements were taken after a 4-min warm-up period, it could be assumed that shoe properties were stable. Then the stiffness adjustment observed during shoe running might be due to further habituations of the runners to the shod condition. To conclude, it makes sense to run at least 4 minutes before taking measurements in order to avoid runners' stiffness alteration due to shoe property modifications. However, runners could still adapt to the shoe.
Die Validität und Reliabilität von Funktionselementen zur Optimierung der Einlagenversorgung im Sport
- H Baur
- A Hirschmüller
- N Kimmich
- S Müller
- A Gollhofer
- F Mayer
H. Baur, A. Hirschmüller, N. Kimmich, S. Müller, A. Gollhofer and F. Mayer, Die Validität und Reliabilität von Funktionselementen zur Optimierung der Einlagenversorgung im
Sport, Deutsche Zeitschrift für Sportmedizin 54 (2003), S22.
- D A Winter
D.A. Winter, Biomechanics and Motor Control of Human
Gait: Normal, Elderly and Pathological, (2nd ed.), Waterloo,
CA: Waterloo Biomechanics, 1991, 1-150.