Effect of ankle-foot orthoses on gait biomechanics of early stroke patients

The aim of stroke rehabilitation is to allow the patient to regain an efficient walking ability. Ankle foot orthoses (AFOs) are nowadays commonly prescribed for this purpose. However, research backed evidence is necessary to determine the best rehabilitation practice and better understand the interaction between AFO and patient capability during gait. The aim of this study was to investigate the effect of polypropylene solid AFOs on gait biomechanics of early stroke survivors. Three patients, affected by stroke within 2 months from onset, were recruited. 3-D analysis of kinematic outcomes at the pelvis and lower limb joints was pursued at various times during their rehabilitation for a period up to six months. Walking kinematics with and without AFO were compared. For one patient, the contribution of the orthosis to the ankle dorsi/plantarflexion support moment was also quantified, by means of an instrumented AFO. Influence of the AFO at the ankle, knee and hip was found in all three anatomical planes, with main effects visible in the sagittal plane. The AFO allowed the patient to contact the ground with the heel and safely swing the leg forward reducing toe drag and risk of stumbling. The sound leg also gained benefits from AFO use, demonstrating improved joint kinematics as a result of improved stability in the hemiplegic leg. The AFO contributed to the net ankle moment by providing assistance to the dorsiflexor muscles during the first half of stance phase. Although this study was limited to three case studies it provides valuable information with regards to the use of AFO in stroke rehabilitation and should encourage the conduction of research in this field