Contralateral Movement and Extensor Force Generation Alter Flexion Phase Muscle Coordination in Pedaling

2000 ◽  
Vol 83 (6) ◽  
pp. 3351-3365 ◽  
Author(s):  
Lena H. Ting ◽  
Steven A. Kautz ◽  
David A. Brown ◽  
Felix E. Zajac
Keyword(s):  
Muscle Activity ◽  
Tibialis Anterior ◽  
Rectus Femoris ◽  
The Body ◽  
Force Generation ◽  
Mechanical Transmission ◽  
Electromyographic Activity ◽  
Neural Pathways ◽  
Control Mechanisms ◽  
Muscle Coordination

The importance of bilateral sensorimotor signals in coordination of locomotion has been demonstrated in animals but is difficult to ascertain in humans due to confounding effects of mechanical transmission of forces between the legs (i.e., mechanical interleg coupling). In a previous pedaling study, by eliminating mechanical interleg coupling, we showed that muscle coordination of a unipedal task can be shaped by interlimb sensorimotor pathways. Interlimb neural pathways were shown to alter pedaling coordination as subjects pedaling unilaterally exhibited increased flexion-phase muscle activity compared with bilateral pedaling even though the task mechanics performed by the pedaling leg(s) in the unilateral and bilateral pedaling tasks were identical. To further examine the relationship between contralateral sensorimotor state and ipsilateral flexion-phase muscle coordination during pedaling, subjects in this study pedaled with one leg while the contralateral leg either generated an extensor force or relaxed as a servomotor either held that leg stationary or moved it in antiphase with the pedaling leg. In the presence of contralateral extensor force generation, muscle activity in the pedaling leg during limb flexion was reduced. Integrated electromyographic activity of the pedaling-leg hamstring muscles (biceps femoris and semimembranosus) during flexion decreased by 25–30%, regardless of either the amplitude of force generated by the nonpedaling leg or whether the leg was stationary or moving. In contrast, rectus femoris and tibialis anterior activity during flexion decreased only when the contralateral leg generated high rhythmic force concomitant with leg movement. The results are consistent with a contralateral feedforward mechanism triggering flexion-phase hamstrings activity and a contralateral feedback mechanism modulating rectus femoris and tibialis anterior activity during flexion. Because only muscles that contribute to flexion as a secondary function were observed, it is impossible to know whether the modulatory effect also acts on primary, unifunctional, limb flexors or is specific to multifunctional muscles contributing to flexion. The influence of contralateral extensor-phase sensorimotor signals on ipsilateral flexion may reflect bilateral coupling of gain control mechanisms. More generally, these interlimb neural mechanisms may coordinate activity between muscles that perform antagonistic functions on opposite sides of the body. Because pedaling and walking share biomechanical and neuronal control features, these mechanisms may be operational in walking as well as pedaling.

scholarly journals Temporal Changes in Electromyographic Activity and Gait Ability during Extended Walking in Individuals Post-Stroke: A Pilot Study

Healthcare ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 444
Author(s):  
Kazuki Fujita ◽  
Yasutaka Kobayashi ◽  
Masahito Hitosugi
Keyword(s):  
Muscle Activity ◽  
Tibialis Anterior ◽  
Rectus Femoris ◽  
Temporal Changes ◽  
Neuromuscular Fatigue ◽  
Electromyographic Activity ◽  
Mean Frequency ◽  
Abnormal Gait ◽  
Walking Performance ◽  
Over Time

Abnormal gait, particularly in patients with stroke, causes neuromuscular fatigue. We aimed to clarify temporal changes in gait performance and lower limb muscle activity during extended walking in people with stroke hemiplegia. Twelve adults with stroke and eleven healthy controls performed an extended trial involving 20-min continuous walk at a comfortable speed. The primary outcome was electromyography amplitude during the trial and secondary outcomes were walking performance and the instantaneous mean frequency of electromyography during the trial. Data at 1, 6, 12, and 18 min after initiating walking were compared. Performance during extended walking in people with stroke was maintained over time. The electromyography amplitude decreased in the tibialis anterior during the pre-swing phase and increased in the rectus femoris during the single-support phase over time; these changes were similar on the paretic and nonparetic sides. Instantaneous mean frequency decreased over time on the nonparetic side in the tibialis anterior and on the paretic side in the rectus femoris. Healthy subjects did not show any changes over time. The changes in muscle activity in patients with stroke differed between the paretic and nonparetic sides, muscle type, and gait phase; walking performance was maintained despite being affected by neuromuscular fatigue.

Lower-Extremity Muscle Activity During Aquatic and Land Treadmill Running at the Same Speeds

2014 ◽  
Vol 23 (2) ◽  
pp. 107-122 ◽  
Author(s):  
W. Matthew Silvers ◽  
Eadric Bressel ◽  
D. Clark Dickin ◽  
Garry Killgore ◽  
Dennis G. Dolny
Keyword(s):  
Lower Extremity ◽  
Outcome Measures ◽  
Muscle Activity ◽  
Tibialis Anterior ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Swing Phase ◽  
Treadmill Running ◽  
Vastus Medialis ◽  
Lower Extremity Muscle

Context:Muscle activation during aquatic treadmill (ATM) running has not been examined, despite similar investigations for other modes of aquatic locomotion and increased interest in ATM running.Objectives:The objectives of this study were to compare normalized (percentage of maximal voluntary contraction; %MVC), absolute duration (aDUR), and total (tACT) lower-extremity muscle activity during land treadmill (TM) and ATM running at the same speeds.Design:Exploratory, quasi-experimental, crossover design.Setting:Athletic training facility.Participants:12 healthy recreational runners (age = 25.8 ± 5 y, height = 178.4 ± 8.2 cm, mass = 71.5 ± 11.5 kg, running experience = 8.2 ± 5.3 y) volunteered for participation.Intervention:All participants performed TM and ATM running at 174.4, 201.2, and 228.0 m/min while surface electromyographic data were collected from the vastus medialis, rectus femoris, gastrocnemius, tibialis anterior, and biceps femoris.Main Outcome Measures:For each muscle, a 2 × 3 repeated-measures ANOVA was used to analyze the main effects and environment–speed interaction (P ≤ .05) of each dependent variable: %MVC, aDUR, and tACT.Results:Compared with TM, ATM elicited significantly reduced %MVC (−44.0%) but increased aDUR (+213.1%) and tACT (+41.9%) in the vastus medialis, increased %MVC (+48.7%) and aDUR (+128.1%) in the rectus femoris during swing phase, reduced %MVC (−26.9%) and tACT (−40.1%) in the gastrocnemius, increased aDUR (+33.1%) and tACT (+35.7%) in the tibialis anterior, and increased aDUR (+41.3%) and tACT (+29.2%) in the biceps femoris. At faster running speeds, there were significant increases in tibialis anterior %MVC (+8.6−15.2%) and tACT (+12.7−17.0%) and rectus femoris %MVC (12.1−26.6%; swing phase).Conclusion:No significant environment–speed interaction effects suggested that observed muscle-activity differences between ATM and TM were due to environmental variation, ie, buoyancy (presumed to decrease %MVC) and drag forces (presumed to increase aDUR and tACT) in the water.

Mutability of Bifunctional Thigh Muscle Activity in Pedaling due to Contralateral Leg Force Generation

2002 ◽  
Vol 88 (3) ◽  
pp. 1308-1317 ◽  
Author(s):  
S. A. Kautz ◽  
D. A. Brown ◽  
H.F.M. Van der Loos ◽  
F. E. Zajac
Keyword(s):  
Muscle Activity ◽  
Isometric Force ◽  
Force Production ◽  
Rectus Femoris ◽  
Force Generation ◽  
Thigh Muscle ◽  
Work Output ◽  
Thigh Muscles ◽  
Sensorimotor Activity ◽  
Bifunctional Muscle

Locomotion requires uninterrupted transitions between limb extension and flexion. The role of contralateral sensorimotor signals in executing smooth transitions is little understood even though their participation is crucial to bipedal walking. However, elucidating neural interlimb coordinating mechanisms in human walking is difficult because changes to contralateral sensorimotor activity also affect the ipsilateral mechanics. Pedaling, conversely, is ideal for studying bilateral coordination because ipsilateral mechanics can be independently controlled. In pedaling, the anterior and posterior bifunctional thigh muscles develop needed anterior and posterior crank forces, respectively, to dominate the flexion-to-extension and extension-to-flexion transitions. We hypothesized that contralateral sensorimotor activity substantially contributes to the appropriate activation of these bifunctional muscles during the limb transitions. Bilateral pedal forces and surface electromyograms (EMGs) from four thigh muscles were collected from 15 subjects who pedaled with their right leg against a right-crank servomotor, which emulated the mechanical load experienced in conventional two-legged coupled-crank pedaling. In one pedaling session, the contralateral (left) leg pseudo-pedaled (i.e., EMG activity and pedal forces were pedaling-like, but pedal force was not allowed to affect crank rotation). In other sessions, the mechanically decoupled contralateral leg was first relaxed and then produced rhythmic isometric force trajectories during either leg flexion or one of the two limb transitions of the pedaling leg. With contralateral force production in the extension-to-flexion transition (predominantly by the hamstrings), rectus femoris activity and work output increased in the pedaling leg during its flexion-to-extension transition, which occurs simultaneously with contralateral extension-to-flexion in conventional pedaling. Similarly, with contralateral force production in the other transition (i.e., flexion-to-extension; predominantly by rectus femoris), hamstrings activity and work output increased in the pedaling leg during its extension-to-flexion transition. Therefore rhythmic isometric force generation in the contralateral leg supported the ongoing bifunctional muscle activity and resulting work output in the pedaling leg. The results suggest that neural interlimb coordinating mechanisms fine-tune bifunctional muscle activity in rhythmic lower-limb tasks to ensure limb flexion/extension transitions are executed successfully.

Comparison of Estimated and Measured Muscle Activity During Inclined Walking

2016 ◽  
Vol 32 (2) ◽  
pp. 150-159 ◽  
Author(s):  
Nathalie Alexander ◽  
Hermann Schwameder
Keyword(s):  
Trend Analysis ◽  
Muscle Activity ◽  
Tibialis Anterior ◽  
Vastus Lateralis ◽  
A Priori ◽  
Correlation Coefficients ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Musculoskeletal Models ◽  
Downhill Walking

While inclined walking is a frequent daily activity, muscle forces during this activity have rarely been examined. Musculoskeletal models are commonly used to estimate internal forces in healthy populations, but these require a priori validation. The aim of this study was to compare estimated muscle activity using a musculoskeletal model with measured EMG data during inclined walking. Ten healthy male participants walked at different inclinations of 0°, ± 6°, ± 12°, and ± 18° on a ramp equipped with 2 force plates. Kinematics, kinetics, and muscle activity of the musculus (m.) biceps femoris, m. rectus femoris, m. vastus lateralis, m. tibialis anterior, and m. gastrocnemius lateralis were recorded. Agreement between estimated and measured muscle activity was determined via correlation coefficients, mean absolute errors, and trend analysis. Correlation coefficients between estimated and measured muscle activity for approximately 69% of the conditions were above 0.7. Mean absolute errors were rather high with only approximately 38% being ≤ 30%. Trend analysis revealed similar estimated and measured muscle activities for all muscles and tasks (uphill and downhill walking), except m. tibialis anterior during uphill walking. This model can be used for further analysis in similar groups of participants.

Neuromuscular Activation During Short-Track Speed Skating in Young Athletes

2016 ◽  
Vol 11 (7) ◽  
pp. 848-854 ◽  
Author(s):  
Sabine Felser ◽  
Martin Behrens ◽  
Susanne Fischer ◽  
Mario Baeumler ◽  
Ralf Salomon ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Tibialis Anterior ◽  
Muscle Activation ◽  
Time Trial ◽  
Rectus Femoris ◽  
Young Athletes ◽  
Neuromuscular Activation ◽  
Leg Muscles ◽  
Maximum Effort ◽  
The Right

Purpose:To investigate differences in muscle activation of both legs between the straight and the curve and changes in muscle activity during a 1000-m time trial (TT) and their relationship to the change in skating velocity in 9 young short-track speed skaters. The authors recorded skating times and EMG data from different leg muscles during maximum-effort skating trials on the straight and in the curve, as well as during a 1000-m TT.Results:Muscle activation differs between the straight and the curves and between legs; ie, average activities of selected muscles of the right leg were significantly higher during skating through the curves than in the straights. This could not be observed for the left leg. The reduction in speed during the 1000-m TT highly correlates with the decrease in the muscle activity of both the tibialis anterior and the rectus femoris of the right leg. Muscle recruitment is different in relation to lap section (straight vs curve) and leg (right vs left leg). The decreased muscle activity of the tibialis anterior and rectus femoris of the right leg showed the highest relationships with the reduction in skating speed during the 1000-m TT.

scholarly journals Perceptibility of Large and Sequential Changes in Somatosensory Information during Leaning Forward and Backward When Standing

2003 ◽  
Vol 96 (2) ◽  
pp. 549-577 ◽  
Author(s):  
Hitoshi Asai ◽  
Katsuo Fujiwara
Keyword(s):  
Individual Differences ◽  
Muscle Activity ◽  
Tibialis Anterior ◽  
Rectus Femoris ◽  
Cooling Condition ◽  
Maximum Pressure ◽  
Abductor Hallucis ◽  
Foot Pressure ◽  
Somatosensory Information ◽  
Pressure Sensation

11 healthy young men served as subjects in two experiments on perceptibility of (1) large changes in foot pressure and muscle activity induced by body leaning and (2) sequential changes in pressure at the first toe and the head of the first metatarsalis when leaning forward. The effects of reduced sensitivity on that perceptibility were also studied by repeating the experiments while cooling localized plantar areas of the sole (the head of the first metatarsalis, the first toe, and the heel). Under the normal (noncooled) condition, all subjects accurately perceived maximum pressure at the head of the first metatarsalis, but most subjects misperceived the second large increase in pressure at the first toe and in muscle activity as the first large increase. Under the cooling condition, localized cooling did not affect the perceptibility of maximum pressure at the head of the first metatarsalis or the activity in the tibialis anterior, but the perceptibility of pressure at the first toe and activity of the abductor hallucis were reduced. There were individual differences in perceptibility of activity of the rectus femoris when the heel was cooled. Perceptibility of sequential changes in the pressure was affected differently by the localized cooling of each region. Given these findings, we discussed the role and interrelatedness of pressure sensation in perceiving large and sequential changes in somatosensory information while standing and leaning forward and backward.

Muscle Activity During Running With Different Body-Weight-Support Mechanisms: Aquatic Environment Versus Body-Weight-Support Treadmill

2014 ◽  
Vol 23 (4) ◽  
pp. 300-306 ◽  
Author(s):  
John A. Mercer ◽  
Bryon C. Applequist ◽  
Kenji Masumoto
Keyword(s):  
Body Weight ◽  
Muscle Activity ◽  
Tibialis Anterior ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Body Weight Support ◽  
Stride Frequency ◽  
Positive Pressure ◽  
Lower Extremity Muscle ◽  
Weight Support

Background:Body-weight (BW) support during running can be accomplished using deep-water running (DWR; 100% BW support) and a lower-body positive-pressure (LBPP) treadmill.Purpose:To compare lower-extremity muscle activity during DWR and running on an LBPP treadmill at matched stride frequency.Methods:Eight subjects (40 ± 6.5 y, 173 ± 7.2 cm, 66.9 ± 11.7 kg) completed 4 running conditions all at a preferred stride frequency that was determined while running with no support. Two conditions were running on the LBPP treadmill at 60% and 80% of BW, and the other 2 conditions were different DWR styles: high knee (DWR-HK) and cross-country (DWR-CC). Average (AVG) and root-mean-square (RMS) electromyography (rectus femoris, biceps femoris, gastrocnemius, and tibialis anterior) were each compared among conditions (repeated-measures analysis of variance).Results:Results for AVG and RMS variables were identical for statistical tests for each muscle. Rectus femoris electromyography during DWR-HK was lower than that of DWR-CC (P < .05) but not different than either 60% BW or 80% BW (P > .05). Biceps femoris electromyography was less during DWR-HK than DWR-CC (P < .05) but greater during DWR-HK than either BW 60% or BW 80% (P < .05). Neither gastrocnemius nor tibialis anterior electromyography differed between conditions (P > .05).Conclusion:Neither the mechanism of BW support nor style of DWR influenced gastrocnemius or tibialis anterior muscle activity during running at the same stride frequency. However, rectus femoris and biceps femoris muscle activity were influenced by not only the mechanism of BW support but also the style of DWR.

scholarly journals Evaluation of lower limb electromyographic activity when using unstable shoes for the first time: A pilot quasi control trial

2012 ◽  
Vol 37 (4) ◽  
pp. 275-281 ◽  
Author(s):  
Helen Branthwaite ◽  
Nachiappan Chockalingam ◽  
Anand Pandyan ◽  
Gaurav Khatri
Keyword(s):  
Muscle Activity ◽  
Repeated Measures ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Medial Gastrocnemius ◽  
Heel Strike ◽  
Electromyographic Activity ◽  
Temporal Parameters ◽  
Unstable Shoes ◽  
First Time

Background: Unstable shoes, which have recently become popular, claim to provide additional physiological and biomechanical advantages to people who wear them. Alterations in postural stability have been shown when using the shoe after training. However, the immediate effect on muscle activity when walking in unstable shoes for the first time has not been investigated. Objective: To evaluate muscle activity and temporal parameters of gait when wearing Masai Barefoot Technology shoes® for the first time compared to the subject’s own regular trainer shoes. Study Design: A pilot repeated-measures quasi control trial. Method: Electromyographic measurements of lower leg muscles (soleus, medial gastrocnemius, lateral gastrocnemius, tibialis anterior, peroneus longus, rectus femoris, biceps femoris and gluteus medius) were measured in 15 healthy participants using Masai Barefoot Technology shoes and trainer shoes over a 10-m walkway. Muscle activity of the third and sixth steps was used to study the difference in behaviour of the muscles under the two shoe conditions. Temporal parameters were captured with footswitches to highlight heel strike, heel lift and toe off. Paired samples t-test was completed to compare mean muscle activity for Masai Barefoot Technology and trainer shoes. Results: Indicated that the use of Masai Barefoot Technology shoes increased the intensity of the magnitude of muscle activity. While this increase in the activity was not significant across the subjects, there were inter-individual differences in muscle activity. This variance between the participants demonstrates that some subjects do alter muscle behaviour while wearing such shoes. Conclusion: A more rigorous and specific assessment is required when advising patients to purchase the Masai Barefoot Technology shoe. Not all subjects respond positively to using unstable shoes, and the point in time when muscle behaviour can change is variable. Clinical relevance Use of Masai Barefoot Technology shoe in patient management should be monitored closely as the individual muscle changes and the point in time when changes occur vary between subjects, and evaluation of how a subject responds is not yet clear.

Impaired muscle phasing systematically adapts to varied relative angular relationships during locomotion in people poststroke

2011 ◽  
Vol 105 (4) ◽  
pp. 1660-1670 ◽  
Author(s):  
Laila Alibiglou ◽  
David A. Brown
Keyword(s):  
Muscle Activity ◽  
Muscle Activation ◽  
Activity Patterns ◽  
Spatial Relationship ◽  
Rectus Femoris ◽  
Vastus Medialis ◽  
Muscle Coordination ◽  
Muscle Activation Patterns ◽  
Relative Contribution ◽  
Muscle Phasing

After stroke, hemiparesis will result in impairments to locomotor control. Specifically, muscle coordination deficits, in the form of inappropriately phased muscle-activity patterns, occur in both the paretic and nonparetic limbs. These dysfunctional paretic muscle-coordination patterns can adapt to somatosensory inputs, and also the sensorimotor state of nonparetic limb can influence paretic limb. However, the relative contribution of interlimb pathways for improving paretic muscle-activation patterns in terms of phasing remains unknown. In this study, we investigated whether the paretic muscle-activity phasing can be influenced by the relative angular-spatial relationship of the nonparetic limb by using a split-crank ergometer, where the cranks could be decoupled. Eighteen participants with chronic stroke were asked to pedal bilaterally during each task while surface electromyogram signals were recorded bilaterally from four lower extremity muscles (vastus medialis, rectus femoris, tibialis anterior, and soleus). During each experiment, the relative angular crank positions were manipulated by increasing or decreasing their difference by randomly ordered increments of 30° over the complete cycle [0° (in phase pedaling), 30°, 60°, 90°, 120°, 150°, 180° (standard pedaling), 210°, 240°, 270°, 300°, 330° (out of phase pedaling)]. We found that the paretic and nonparetic muscle phasing in the cycle systematically adapted to varied relative angular relationships, and this systematic relationship was well modeled by a sinusoidal relationship. Also, the paretic uniarticular muscle (vastus medialis) showed larger phase shifts compared with biarticular muscle (rectus femoris). More importantly, for each stroke subject, we demonstrated an exclusive crank-angular relation that resulted in the generation of more appropriately phased paretic muscle activity. These findings provide new evidence to better understand the capability of impaired nervous system to produce a more normalized muscle-phasing pattern poststroke.

scholarly journals Effects of Plyometric Training on Surface Electromyographic Activity and Performance during Blocking Jumps in College Division I Men’s Volleyball Athletes

2020 ◽  
Vol 10 (13) ◽  
pp. 4535
Author(s):  
Min-Hsien Wang ◽  
Ke-Chou Chen ◽  
Min-Hao Hung ◽  
Chi-Yao Chang ◽  
Chin-Shan Ho ◽  
...  
Keyword(s):  
Tibialis Anterior ◽  
Vertical Jump ◽  
Rectus Femoris ◽  
Electromyographic Activity ◽  
Median Frequency ◽  
Jump Height ◽  
Plyometric Training ◽  
Vertical Jump Height ◽  
Male College ◽  
Volleyball Players

In volleyball matches, there are three minute intervals between sets. Therefore, the improvement of the muscle output ratio is one of the most import foundational physical elements for the players. The purpose of this study was to investigate the effects of plyometric training on the changes in electrical signals in the lower limb muscles of male college volleyball players during continuous blocking and to examine the benefits of plyometric training on blocking agility and maximum vertical jump height. In this study, twenty elite male college volleyball players were recruited and divided into a plyometric training group (PTG) and a control group (CG). The wireless electromyography was used for data acquisition, and the electrodes were applied to the left and right rectus femoris, biceps femoris, tibialis anterior, and gastrocnemius. The median frequency was used as the measurement of the electromyographic signals during the jumping blocks. This study used covariate analysis methods, with previously measured results used as covariates to perform a two-way analysis of covariance for the independent samples. Based on the results of this study, after 6 weeks of training, the median frequency of the rectus femoris (2.13% to 4.75% improved) and that of the tibialis anterior muscles (4.14% to 7.71% improved) were significantly lower in the PTG than in the CG. Additionally, the blocking agility increased by 6.26% and the maximum vertical jump height increased by 3.33% in the PTG compared to the CG. The findings provide important insights on the neuromuscular status for volleyball players during continuous blocking jumps. Six weeks of appropriate plyometric training can facilitate the performance of volleyball players.

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