Stiff-knee gait in cerebral palsy: How do patients adapt to uneven ground?

- First study that showed adaptive mechanism to uneven surface condition in CP.
- Patients with stiff-knee gait showed similar adaptability than healthy controls.
- Patients with stiff-knee gait were able to flex their knee when it was necessary to prevent falling.
- Patients with stiff-knee gait increased knee flexion although rectus femoris activity increased.
- Training on uneven surface might be an option to improve stiff-knee gait.

Patients with cerebral palsy frequently experience foot dragging and tripping during walking due to reduced toe clearance mostly caused by a lack of adequate knee flexion in swing (stiff-knee gait). The aim of this study was to investigate adaptive mechanism to an uneven surface in stiff-knee walkers with cerebral palsy. Sixteen patients with bilateral cerebral palsy, GMFCS I-II and stiff-knee gait, mean age 14.1 (SD = 6.2) years, were compared to 13 healthy controls with mean age 13.5 (SD = 4.8) years. Gait analysis including EMG was performed under even and uneven surface conditions. Similar strategies to improve leg clearance were found in patients as well as in controls. Both adapted with significantly reduced speed and cadence, increased outward foot rotation, knee and hip flexion as well as anterior pelvic tilt. Therefore cerebral palsy and stiff-knee gait did not affect the adaptation capacity on the uneven surface.On the uneven surface an average increase in knee flexion of 7° (SD = 3°) and 12° (SD = 5°) was observed in controls and patients with cerebral palsy, respectively. Although rectus femoris activity was increased in patients with cerebral palsy, they were able to increase their knee flexion during swing. The results of this study suggest that walking on uneven surface has the potential to improve knee flexion in stiff-knee walkers. Therefore training on uneven surface could be used as a conservative treatment regime alone, in combination with Botulinum neurotoxin or in the rehabilitation of surgery.