Effectiveness of ankle-foot orthoses for improving gait in polio survivors

Many polio survivors who suffer from calf muscle weakness experience gait problems that hinder activities during daily life. Common problems during gait are instability, fatigue due to increased energy cost of walking and pain. Custom-made dorsiflexion restricting ankle-foot orthoses (DR-AFOs) are often prescribed to compensate for calf muscle weakness and therewith to improve gait. While most polio survivors are satisfied with their prescribed DR-AFO, some polio survivors are not satisfied and do not use the DR-AFO while still experiencing gait problems. This thesis provides evidence for the effectiveness of custom DR-AFOs for improving gait, walking energy cost, comfortable walking speed and satisfaction. It further shows that the effectiveness can be improved by individually adjusting the degree of dorsiflexion restriction of the DR-AFO. Which setting is needed for the largest improvement differs per person. Energy cost during walking may be improved by adjusting the DR-AFO in such a way that the maximal ankle moment increases by an increased center of pressure progression along the foot. Finally, to promote satisfaction and use of the DR-AFO, the DR-AFO should be experienced comfortable and should not interfere with activities other than walking. Furthermore, the DR-AFO is more likely to be used when it is perceived as effective on predetermined goals by the patient and rehabilitation specialist. These usability aspects are therefore important to assess and evaluate when prescribing DR-AFOs for polio survivors with calf muscle weakness.