Related Experiment Video
Updated: Aug 13, 2026
Evaluating Postural Control and Lower-extremity Muscle Activation in Individuals with Chronic Ankle Instability
Published on: September 18, 2020
Changes in muscle activity in children with hemiplegic cerebral palsy while walking with and without ankle-foot
J Romkes1, A K Hell, R Brunner
1Laboratory for Gait Analysis Basel, Children's University Hospital (UKBB), Burgfelderstrasse 101, CH-4012 Basel, Switzerland. J.Romkes@unibas.ch
Insights
Hinged ankle-foot orthoses (HAFOs) improve walking in children with cerebral palsy (CP). HAFOs promote a heel-toe gait, reduce muscle activity, and enhance overall walking kinematics.
Area of Science:
- Biomechanics
- Neurology
- Orthotics
Background:
- Hemiplegic cerebral palsy (CP) often results in abnormal gait patterns, including excessive plantarflexion and initial toe-contact.
- Electromyographic (EMG) analysis is crucial for understanding muscle activation during gait in individuals with CP.
Purpose of the Study:
- To compare lower extremity muscle EMG signals in children with hemiplegic CP during barefoot walking versus walking with a hinged ankle-foot orthosis (HAFO).
- To evaluate the kinematic and kinetic effects of HAFOs on gait in this population.
Main Methods:
- EMG data from lower extremity muscles were collected from 10 children with hemiplegic CP.
- Gait analysis was performed while participants walked barefoot and while wearing a HAFO.
- Key gait parameters including muscle activity, stride length, cadence, and walking speed were measured.
Main Results:
- HAFO use shifted gait from toe-contact to a physiological heel-toe pattern.
- Peak tibialis anterior muscle activity decreased significantly (36.1% at initial contact, 57.3% post-toe-off) with HAFO use.
- HAFOs also reduced proximal leg muscle activity, improved stride length and walking speed, decreased cadence, and enhanced knee and hip kinematics.
Conclusions:
- HAFOs effectively normalize gait patterns in children with hemiplegic CP.
- The observed improvements in muscle activity and kinematics suggest HAFOs are beneficial for gait rehabilitation in this population.
Abstract:
We compared the electromyographic (EMG) signals of lower extremity muscle groups in 10 children with hemiplegic cerebral palsy (CP) while walking barefoot and in a hinged ankle-foot orthosis (HAFO). All children had excessive plantarflexion and initial toe-contact on the affected side when walking barefoot, a typical gait pattern for hemiplegic patients. The patients walked with a physiological heel-toe gait pattern when wearing the HAFO. The peak activity of the tibialis anterior muscle was reduced by 36.1% at initial contact and loading response phase and by 57.3% just after toe-off when using a HAFO. The decrease in activity was thought to result from the change in gait pattern from a toe-gait to a heel-toe gait as well as the use of a HAFO. The HAFO also slightly decreased muscle activity in the proximal leg muscles mainly during swing phase, improved stride length, decreased cadence, improved walking speed, increased peak hip flexion, improved kinematics in loading response phase at the knee, and reduced the excessive ankle plantarflexion.
