Kinematic features of rear-foot motion using anterior and posterior ankle-foot orthoses in stroke patients with hemiplegic gait

Objective To evaluate the kinematic features of rear-foot motion during gait in hemiplegic stroke patients, using anterior ankle-foot orthoses (AFOs), posterior AFOs, and no orthotic assistance. Design Crossover design with randomization for the interventions. Setting A rehabilitation center for adults with neurologic disorders. Participants Patients with hemiplegia due to stroke (n=14) and able-bodied subjects (n=11). Interventions Subjects with hemiplegia were measured walking under 3 conditions with randomized sequences: (1) with an anterior AFO, (2) with a posterior AFO, and (3) without an AFO. Control subjects were measured walking without an AFO to provide a normative reference. Main Outcome Measures Rear-foot kinematic change in the sagittal, coronal, and transverse planes. Results In the sagittal plane, compared with walking with an anterior AFO or without an AFO, the posterior AFO significantly decreased plantar flexion to neutral at initial heel contact (P=.001) and the swing phase (P<.001), and increased dorsiflexion at the stance phase (P=.002). In the coronal plane, the anterior AFO significantly increased maximal eversion to neutral (less inversion) at the stance phase (P=.025), and decreased the maximal inversion angle at the swing phase when compared with using no AFO (P=.005). The posterior AFO also decreased the maximal inversion angle at the swing phase as compared with no AFO (P=.005). In the transverse plane, when compared with walking without an AFO, the anterior AFO and posterior AFO decreased the adduction angle significantly at initial heel contact (P=.004). Conclusions For poststroke hemiplegic gait, the posterior AFO is better than the anterior AFO in enhancing rear-foot dorsiflexion during a whole gait cycle. The anterior AFO decreases rear-foot inversion in both the stance and swing phases, and the posterior AFO decreases the rear-foot inversion in the swing phase when compared with using no AFO.