Effects of Functional Electrical Stimulation with and without a Wrist-Hand Orthosis on Hand Opening in Individuals with Chronic Hemiparetic Stroke: A Pilot Study

Abstract

Objective: Many individuals with stroke cannot open their affected hand in a functional way: they either produce insufficient hand opening, or achieve hand opening while flexing their wrist. Insufficient hand-opening in post-stroke individuals can be improved by applying functional electrical stimulation (FES) to finger/thumb extensors. However, how to reduce the coupling between finger extension and wrist flexion is still unknown. Both FES to wrist extensors and a wrist-hand orthosis (WHO) can assist holding the wrist in a close-to-neutral position. This may or may not improve purposeful use of the paretic arm, depending on how it will interfere with hand opening. Therefore, this study investigated how using either FES or WHO to maintain the wrist in a close-to-neutral position will impact the FESassisted hand opening. Methods: We recruited twelve individuals with moderate to severe stroke to participate. They performed maximal hand opening with or without assistance from FES/WHO. Hand opening distance and wrist flexion angle were measured. Results: Our results demonstrated that FES applied to the finger extensors resulted in a trend of larger opening distance (p 0.2); however, a trend of reduced wrist flexion angle (p=0.057) when using WHO combined with FES. Conclusion: These results suggest that combined FES and WHO should be considered when designing interventions or devices to enhance hand opening in individuals with stroke.