Abstract
This report deals with cervical injuries who suffer from spasms and paralysis of extremities. Their ability to manipulate a computer screen pointing device was studied. The subjects attempted to aim the pointing device, a single-speed floating action joystick, so that the cursor overlapped the target provided on CRT display. Their ability was examined at eight cursor speed levels within two subject groups; eight cervical injuries and three abled persons.
The subject's total operating time was comprised of reaction time, approaching time to target, adjusting time near target with detailed behavior, and switching time. Similar operational time patterns for cursor speed were observed in both groups. At the adjusting operation on high speed level, inching operation were repeated. Inching operation times consisted of inching ON-time and OFF-time. The subject's ON-times converged near the controllable minimum. The ON-times of the cervical injury group were longer than those of abled person. OFF-times were longer than ON-times, with a positively skewed distribution. The OFF-time distribution was also wider for the cervical injury group.
