Practice of a precision isometric grip-force task by children with spastic cerebral palsy

The ability to produce and sustain a criterion level of precision isometric grip force was studied in a group of 7- to 12-year-old children with cerebral palsy (CP) and in a control group. on-line visual feedback of the forces produced relative to a stationary target was provided for each B-second trial. Subjects practised 48 trials on each of 3 consecutive days. Measures of accuracy and variability revealed significantly reduced accuracy and increased variability in isometric force production for the group with CP. Both groups demonstrated improvement with practice, with the significantly greater change in the control subjects. There was substantial variability in performance among subjects with CP. Gains associated with practice were sustained over a 5-day retention interval for both groups. The requirement to control proximal segments of the upper extremity was not associated with increased error in grip-force production of the group with CP.