Ankle-angle analysis of drop-foot patients in walking with FES

The purpose of this study is to develop a potential method to quantify the effect of functional electrical stimulation (FES) on hemiplegic drop-foot (HDF) patients´ movements. This method evaluates the effect of FES by comparing the ankle-angles of movements with and without FES. The change of the ankle-angles is one of the significant characteristics of the recovery of drop-foot. Therefore, this measurement method evaluates FES-assisted walking quantitatively through biomechanical properties of human gait. A group of subjects were asked to walk in the laboratory. Their walking performance was recorded by Vicon motion capture system. For each subject, a static trial and six walking trials were recorded. The data were sent to computer to establish the 3D model by Vicon Nexus software to calculate the ankle-angles of the drop-foot. The changes of the ankle-angles are obvious in the graphs. Statistical data analysis procedure for hypothesis testing was used to get a reliable result. Ankle-angles of movements were calculated to P values (P<;0.05). The results show that FES is effective and the method is reliable. These clinical trial results suggest that using motion capture is a reliable and practicable way to evaluate hemiplegic drop-foot patients´ dorsiflexion. This method will probably be used in carrying out a potential optimized stimulation intensity envelope for hemiplegic drop-foot stimulator. And the biomechanics of the ankle joint during the gait cycle also provide a way to the stroke patients to observe their recovery.