Development of a virtual reality-based pinch task for rehabilitation in chronic hemiparesis

Impaired pinch performance affects dexterity function after stroke. Virtual reality-based training may be beneficial for improving dexterity function. This study aimed to develop a virtual reality-based pinch task and to investigate its feasibility for chronic hemiparesis. The pinch task in the virtual environment was accomplished by coordinating two PHANTOM devices that provide haptic feedback. Participants grasped and lifted a virtual cube with 30-sec time limit for 10 trials. Cube size, cube mass and lift height were systematically varied. The participant poststroke attempted an average of 38 trials per session with a 60 % success rate and without complaint of fatigue or pain. After the training, the participant poststroke decreased the total time. However, the peak pinch force did not change. The results suggest that the virtual reality-based pinch task was feasible for chronic hemiparesis. Further investigation is warranted to better understand the effect of pinch force regulation using hepatic feedback.