Effect of task goals on the reaching patterns of children with cerebral palsy

The authors examined whether the intended task goal of the subsequent action affects the reaching patterns before the intended goal in 17 children with cerebral palsy (CP). The authors hypothesized that when the children with CP used their less affected hand, they would not be affected by the task goals and that their reaching pattern would deviate from those of 17 age-matched children without CP and 20 young healthy adult participants. All participants were instructed to reach and grasp a tennis ball and then to either fit or throw it. Kinematic variables (movement time, straightness ratio, peak velocity, percentage of time to peak velocity, and number of movement units) were used as outcome measures. Children with CP used slower, less straight, less forceful, and jerkier reaching patterns to approach the object than did children without CP and adults. Unlike in children and adults without CP, the intended goal of the subsequent action did not affect the reaching pattern before the intended goal in children with CP. Children with CP may therefore have difficulty in anticipatory planning and thus must segment the integrative action plan into sequential submovements.