Background: Kinematic investigations of prehension movements made by children with cerebral palsy are few and mainly focus on the reaching phase. To increase understandings of how both reaching and grasping movements are organized in these children, the aim was to investigate their spatiotemporal characteristics and additionally, how different kinematic parameters are related to the level of hand functions.
Methods: Eleven children with hemiplegic cerebral palsy; categorized as "mild" and "moderate", in their age of 5.8-12 years and eleven typically developing, "control" children participated. Reaching and grasping made with both the affected/non-preferred and unaffected/preferred sides were recorded and several kinematic parameters investigated.
Findings: In comparison to the control and the mild hemiplegic children, the moderate children exhibited more segmented reaches, longer reach- and grasp durations, and with no anticipatory shaping of the fingers when grasping with the affected hand. Their reaching path with the "unaffected" hand was also more segmented. The mild hemiplegic children showed ability for anticipatory hand closure and performed reaches with similar duration and trajectory as controls. The velocity at hand-object-contact and the quality of their grasping was however affected in comparison to the controls.
Interpretation: Findings from the investigated kinematics provide evidence of how spatiotemporal organization of reaching and grasping are affected in children with hemiplegia and related to the level of impaired hand functions. The outcomes clearly show that if these children are treated as one homogeneous group much information about their prehension capacity described from the kinematics will be concealed. Thus, observations of importance for developing effective, individual interventions adjusted to different level of impairments.