Effect of Anterior Ankle-Foot Orthoses on Weight Shift in Persons with Stroke

Objective To examine the effects of an anterior ankle-foot orthosis (AAFO) on the speed and accuracy of weight shift in persons with stroke. Design Cross sectional, repeated measures. Setting Neurologic rehabilitation department. Participants People with stroke (N=24) who were unable to voluntarily dorsiflex the foot against gravity. Intervention The weight-shift performance was measured with and without the AAFO. Main Outcome Measures The speed and accuracy of sustained and cyclic bilateral weight shift were measured using the computerized dynamic posturography. The movement velocity, maximum excursion, and directional control of sustained weight shift were calculated using the limits of stability test. The on-axis velocity gap, directional control, and stability of cyclic bilateral weight shift were calculated using the rhythmic weight shift test. Results For sustained weight shift, the maximum excursion of weight shift to the affected side was greater with the AAFO (P=.002). For cyclic bilateral weight shift, the on-axis velocity gap in the mediolateral (ML) direction was smaller at a fast speed (P=.004). The stability of the ML and anteroposterior weight shift was higher at slow (P=.002 and P<.001, respectively) and fast (P=.001 and P<.001, respectively) speeds when wearing the AAFO. Conclusions The findings demonstrated that persons with stroke who wear an AAFO might improve the excursion of the sustained weight shift to the affected side and the speed and stability of cyclic bilateral weight shift in the ML direction.