Related Experiment Video
Updated: Jul 9, 2025
Author Spotlight: Repetitive Transcranial Magnetic Stimulation Combined with Movement Observation in Cerebral Palsy
Published on: August 9, 2024
Muscle coactivation during gait in children with and without cerebral palsy
P Ippersiel1, C Dussault-Picard1, S G Mohammadyari1
1School of Kinesiology and Physical Activity Sciences, Faculty of Medicine, University of Montreal, Canada; Research Center of the CHU Sainte-Justine, Montreal, Canada.
Insights
Children with Cerebral Palsy (CP) exhibit greater lower-limb muscle co-activation during gait, suggesting a less stable walking pattern. This finding holds true regardless of electromyography data normalization methods used.
Area of Science:
- Biomechanics
- Neurology
- Pediatrics
Background:
- Children with Cerebral Palsy (CP) often display uncoordinated gait compared to typically developing (TD) children.
- This gait difference may stem from increased lower-limb muscle co-activation, but research findings are inconsistent.
Purpose of the Study:
- To compare lower-limb muscle co-activation during gait in children with and without CP.
- To investigate the influence of electromyography normalization methods and Gross Motor Function Classification System (GMFCS) levels on muscle co-activation.
Main Methods:
- Electromyography measured lower-limb muscle activity in 46 children (19 CP, 27 TD) during walking.
- Muscle co-activation was calculated for specific muscle pairs using both RMS-averaged and dynamically normalized data.
- Statistical analyses compared co-activation between groups and by GMFCS level.
Main Results:
- Children with CP showed significantly greater muscle co-activation in several muscle pairs during stance and swing, depending on the normalization method.
- Dynamically normalized data revealed higher co-activation in the CP group for tibialis anterior-gastrocnemius (TA-G) and rectus femoris-gastrocnemius (RF-G) during stance.
- Muscle co-activation values were influenced by normalization procedures, but the increased co-activation in CP was consistent across methods.
Conclusions:
- Elevated muscle co-activation in children with CP during gait, particularly in the stance phase, may indicate a less robust walking strategy.
- While normalization techniques affect co-activation measures, the presence of greater co-activation in children with CP is a consistent finding.
Background:
Children with Cerebral Palsy (CP) walk with an uncoordinated gait compared to Typically Developing (TD) children. This behavior may reflect greater muscle co-activation in the lower limb; however, findings are inconsistent, and the determinants of this construct are unclear.
Research Objectives:
(i) Compare lower-limb muscle co-activation during gait in children with, and without CP, and (ii) determine the extent to which muscle co-activation is influenced by electromyography normalization procedures and Gross Motor Function Classification System (GMFCS) class.
Methods:
An electromyography system measured muscle activity in the rectus femoris, semitendinosus, gastrocnemius, and tibialis anterior muscles during walking in 46 children (19 CP, 27 TD). Muscle co-activation was calculated for the tibialis anterior-gastrocnemius (TA-G), rectus femoris-gastrocnemius (RF-G), and rectus femoris-semitendinosus (RF-S) pairings, both using root mean squared (RMS)-averaged and dynamically normalized data, during stance and swing. Mann-Whitney U and independent t-tests examined differences in muscle co-activation by group (CP vs. TD) and GMFCS class (CP only), while mean difference 95% bootstrapped confidence intervals compared electromyography normalization procedures.
Results:
Using dynamically normalized data, the CP group had greater muscle co-activation for the TA-G and RF-G pairs during stance (p < 0.01). Using RMS-averaged data, the CP group had greater muscle co-activation for TA-G (stance and swing, p < 0.01), RF-G (stance, p < 0.05), and RF-S (swing, p < 0.01) pairings. Muscle co-activation calculated with dynamically normalized, compared to RMS-averaged data, were larger in the RF-S and RF-G (stance) pairs, but smaller during swing (RF-G). Children with CP classified as GMFCS II had greater muscle co-activation during stance in the TA-G pair (p < 0.05).
Significance:
Greater muscle co-activation observed in children with CP during stance may reflect a less robust gait strategy. Although data normalization procedures influence muscle co-activation ratios, this behavior was observed independent of normalization technique.
More Related Videos
Related Concept Videos
01:24Muscle Coordination and Action
Agonists
Agonist muscles, often called prime movers, are the primary muscles responsible for producing a specific movement....
01:20Excitation-Contraction Coupling in Skeletal Muscles
When an action...