The effect of hinged ankle-foot orthoses on sit-to-stand transfer in children with spastic cerebral palsy

Objective: To investigate the effectiveness of the hinged ankle-foot orthosis (AFO) on sit-to-stand (STS) transfers in children with spastic cerebral palsy. Design: Before-after trial. Setting: University-affiliated hospital. Participants: Nineteen spastic diplegic children (age range, 2-6y). Interventions: Not applicable. Main Outcome Measures: The transitional movement of STS was tested in random order with children while wearing the barefoot and hinged AFOs. The temporal, kinematic, and kinetic data during the task were collected by using a motion analyzer (with 6 infrared cameras). Statistical comparison between barefoot and hinged AFO was done with the Wilcoxon signed-rank test. Results: Total duration of STS transfer was significantly shortened with the hinged AFO (P<.05). The initial knee flexion, the initial angle, and the final angle of ankle dorsiflexion were increased with the AFO, compared with when barefoot (P<.05). However, the increased pelvic tilt and hip flexion while barefoot was not reduced with the AFO. The maximal moment and power of hip and knee joints were significantly increased with the AFO (P<.05), whereas the maximal moment and power of the ankle joint were not significantly changed when wearing the AFO. Conclusions: Although proximal compensatory strategy of increased pelvic tilt and hip flexion did not change with the hinged AFO, some improvements of temporal, kinematic, and kinetic parameters were identified during the task. These findings suggest that a hinged AFO is beneficial for STS transfer activity for children with spastic diplegia.