Comparison of virtual wheelchair driving performance of people with traumatic brain injury using an isometric and a conventional joystick

Objective: To compare wheelchair driving performance in a driving simulator using a conventional joystick and an isometric joystick. Design: Randomized, cohort study. Setting: A research facility based in a hospital or in an independent living center. Participants: Participants (N=20; 12 men, 8 women; mean age ± SD, 30.62±10.91y) who were at least 1 year post-TBI. Interventions: Driving performance using an isometric joystick compared with a conventional movement joystick. Main Outcome Measures: Average trial completion time, and trajectory-specific measures measured orthogonal to the center of driving tasks: root mean squared error, movement offset, movement error, and number of significant changes in heading. Results: After statistically controlling for driving speed, participants were able to complete the driving tasks faster with an isometric joystick than while using a conventional movement joystick. Compared with the conventional joystick, an isometric joystick used for driving forward demonstrated fewer driving errors. During reverse driving the conventional joystick performed better. Conclusions: The customizable isometric joystick seems to be a promising interface for driving a powered wheelchair for individuals with TBI.