Effect of task on movement control in cerebral palsy: implications for assessment and therapy.

In order to examine the possibility that children with cerebral palsy (CP) find abstract tasks, such as extending the arm as much as possible, more difficult than concrete tasks, such as reaching to grasp an object, nine hemiparetic children with CP and 12 nursery-school children were tested with both a concrete and an abstract task. The children with CP achieved a significantly larger range of movement in the concrete task, whereas the nursery-school children showed no difference between tasks. Thus the CP children's poorer performance on the abstract task did not fully reflect their movement capability. This means that conventional neurological measurements of limb function in cerebral palsy, which mainly use abstract tasks or passive movements, will give an incomplete picture of the child's action capability.