The effect of an ankle-foot orthosis in walking ability and coordination by hd patients: A pilot study

Background: During the swing phase of the gait of HD patients, some patients show an irregular, uncoordinated movement of the foot, or the foot can not be held in dorsal flexion. These symptoms affect the manner of walking and therefore an individual's ability to participate in daily living. In Overduin, we have been experimenting in walking with an ankle-foot orthosis (AFO) for which we experienced that it seems to improve walking ability of HD patient's. The purpose of this study was to investigate the effect of AFO on walking and movement coordination during gait. Methods: 19 people with HD were tested while walking with and without ankle-foot orthosis. In addition 10 control subjects were tested as a reference. The experimental protocol included a 10 meters walking test, the timed-up-and-go-test and a 6 minutes walking test. During 6 minutes walking test, subjects wore footcontact switches in each shoe and 3D accelerometers on wrist and ankle. From these sensors several parameters describing variability, regularity and inter-limb coordination were derived. The UHDRS total motor score and Total Functional capacity (TFC) were administered for disease severity. The timed walking test and selected parameters describing movement coordination during walking were demonstrated to be able to discriminate between patients and control subjects and to be significantly correlated with the score of UHDRS total motor score Results: None of these parameters, however, revealed a significant effect of AFO on walking distance, speed, variability, regularity, and movement coordination Conclusion: The selected parameters on movement coordination and walking performance do not indicate an effect of AFO on walking in people with HD. Despite the negative result several patients subjectively prefer wearing the AFO. Possibly more complex walking conditions, as for instance climbing the stairs, obstacle negotiation or dual tasks are necessary to reveal significant effect of the AFO. These tests will need to be performed in the future