Evaluation of joysticks in cursor positioning task by individuals with cerebral palsy

Individuals with cerebral palsy with upper limb disability have difficulty operating standard computer input devices such as, a mouse and a keyboard. The present study evaluated the performance of non-disabled individuals and those with cerebral palsy in the use of a zero-order spring-centered position joystick and a zero-order isometric joystick when interacting with the computer. The subjects acquired differently sized targets at different distances by positioning a cursor on the target. The time to acquire the target was directly proportional to the cursor-target distance, and indirectly proportional to the target size. Subjects chose to move more slowly towards the smaller and closer targets and they increased speed for larger and more distant targets. Performance with the position joystick was superior to that of the isometric joystick. Fitts´ paradigm was shown to be a good predictor of the movement time for the non-disabled individuals as well as those with disability