Design of Virtual Guiding Tasks With Haptic Feedback for Assessing the Wrist Motor Function of Patients With Upper Motor Neuron Lesions

Impaired motor function is a common consequence of upper motor neuron lesions (UMNLs). Fine motor skills involved in small movements occurring in the fingers, hand, and wrist are usually regained by patient self-training at home. Most studies focus on the rehabilitation of the fingers but ignore the recovery of wrist motor function. In this paper, three virtual guiding tasks were designed to assess wrist motor functions, including the basic motor flexibility, motion stability, and a range of active motion. A haptic device was used to provide haptic feedback to users who performed virtual tasks in a virtual reality (VR) environment. In total, 46 healthy subjects and 10 UMNL patients were included to test the effectiveness of the designed tasks on improving wrist motor assessments. Quantitative performances, including the completion time, contact force, and motion trajectory, were automatically acquired during the tasks. Measurements for 95% of control subjects were used to establish normative references. Patient deficiencies in the wrist motor function were identified when their quantitative performances were outside the normative control ranges. The results suggest that the designed virtual tasks are sensitive for patients in the later period of rehabilitation, making the assessment suitable for using at home.