Changes in steering performance and muscle activity of the upper extremity according to the position of the spinner knob.

The present study provides basic data for determining the position of the spinner knob attached to the steering wheel when driving one-handed with the non-dominant left hand. Positioning of the knob at 8 o'clock can be recommended on the basis of steering performance and lower muscle activities.IMPLICATIONS FOR REHABILITATIONThe safe driving of an automobile requires the driver to have an adequate range of motion and advanced voluntary motor control of the upper and lower extremities.When steering with the bilateral hands becomes difficult and driving with one-hand is required, it is necessary to attach a spinner knob on the steering wheel.This study provides objective and valuable information for clinicians and therapists to determine the optimum position of the spinner knob.