Related Experiment Videos
Pathophysiology of gait in children with cerebral palsy
Insights
Children with cerebral palsy exhibit muscle co-activation during gait due to impaired motor development. This study investigated leg muscle activity and ankle joint angles in children with and without cerebral palsy during slow walking.
Area of Science:
- Neurology
- Biomechanics
- Pediatrics
Background:
- Cerebral palsy (CP) often involves muscle hypertonia affecting gait.
- Understanding the neuromuscular control of gait in children with CP is crucial for therapeutic interventions.
Purpose of the Study:
- To analyze the gait patterns of children with cerebral palsy by recording surface electromyogram (EMG) and ankle joint angles.
- To compare muscle activity and biomechanics between children with CP and typically developing children during slow gait.
Main Methods:
- Surface electromyogram (EMG) of leg muscles and ankle joint angles were recorded during slow gait.
- 10 normal children and 10 children with cerebral palsy participated in the study.
- Achilles tendon tension was measured in two hemiparetic children.
Main Results:
- Spastic legs in children with CP showed co-activation of antagonistic leg muscles during the stance phase and reduced overall EMG amplitude.
- Increased Achilles tendon tension was observed in the spastic leg at the beginning of the stance phase.
- Unlike adults with CP, reciprocal EMG activity was not preserved in the spastic children.
Conclusions:
- Muscle hypertonia in spastic children during gait may stem from altered muscle fiber mechanical properties.
- Muscle co-activation in spastic children suggests an impaired maturation of the locomotor pattern.
- Early neuronal adaptation to altered muscle mechanics may underlie observed gait deviations in pediatric CP.
Abstract:
The surface electromyogram (EMG) of leg muscles was recorded together with the changes of the angle at the ankle joint during slow gait in 10 normal children and 10 with cerebral palsy. The characteristic pattern of muscle activity recorded from the spastic legs mainly consisted of a co-activation of antagonistic leg muscles during the stance phase of a gait cycle and a general reduction in amplitude of EMG activity. The tension of the Achilles tendon, measured in 2 hemiparetic children during gait, increased much more steeply in the spastic leg than in the normal one at the beginning of the stance phase, when the electrically almost silent triceps surae was stretched. It is suggested that muscle hypertonia during gait in spastic children is mainly due to changed muscle fibre mechanical properties, as recently discussed also for spastic adults. While in the latter the reciprocal EMG activity of antagonistic leg muscles was preserved it is proposed that muscle co-activation recorded in spastic children is due to an impaired maturation of the locomotor pattern with an early neuronal adaptation to altered muscle fibre mechanical characteristics.