This research studied the effects of cerebral palsy on the ability to plan and execute a one-handed aiming task. Simple reaction time (SRT) was fractionated into its premotor (PMT) and motor (MOT) components. Subjects were 20 youths, 10 with cerebral palsy and 10 nonhandicapped youths. The effect of accuracy demands on the planning and execution time was also studied by manipulating endpoint target size. Significant differences in PMT but not in MOT were obtained between groups, indicating that spastic hemiplegic cerebral palsied youths require more time to plan a simple aiming movement due to central processing limitations. Although manipulation of endpoint target size did not affect programming time for either group, the time to execute the movement increased significantly. This finding suggests that instead of incorporating the parameter of movement accuracy in the selected motor program, subjects adopted a feedback driven strategy to achieve greater endpoint accuracy.
This study was conducted in partial fulfillment of the requirements for the PhD at Oregon State University under the guidance of Dr. John Dunn.
Requests for reprints should be sent to Dr. Susan Parks, Springfield Public Schools, Administration Bldg., 525 Mill St., Springfield, OR 97477.