Haptic virtual reality pinch task for chronic hemiparesis

Incorporating the virtual reality technology into stroke rehabilitation has been proved to be effective in improving upper extremity function for stroke survivors. However, without haptic feedback, the recovery of pinch skill will not be sufficient for daily activities. Pinch skill is an important component for hand manipulation. Impaired pinch skill affects dexterity function after stroke. This study aimed to develop a haptic virtual reality pinch task and to investigate its feasibility and effectiveness 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 within 30 seconds 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 training, the participant poststroke decreased the total time. However, the peak pinch force did not change. The results suggest that the haptic virtual reality pinch task was feasible for chronic hemiparesis. Further investigation is warranted to better understand the pinch force regulation using hepatic feedback.