Three-dimensional analysis of performance of an upper limb functional task among adults with dyskinetic cerebral palsy

Patients with dyskinetic cerebral palsy (DCP) experience considerable variability in their purposeful movements due to involuntary movements that contribute to functional impairment. Movement analyses can demonstrate how the movements involved in bringing a mug to the mouth are performed by patients with DCP. Sixteen adults with DCP (29.63. ±. 4.42 years) and eleven healthy adults (24.09. ±. 3.73 years) performed six consecutive movements of bringing a mug to the mouth using their dominant arm. The mug was placed at 75% of each subject's maximum reach. Kinematic data were captured by 10 cameras and processed using biomechanical software. Fifteen reflexive markers were placed on predetermined bony landmarks on the head, trunk and upper limbs. DCP adults required more time to perform the going (bringing the mug to the mouth), adjusting (simulating taking a drink) and returning (lowering the mug back to the table) phases, and their movements were less smooth than the controls, as indicated by the index of curvature, average jerk and number of movement units. The DCP adults took a longer time to complete the task than controls as indicated by the peak velocities, mean velocities and times to peak velocity. With respect to the angular parameters, DCP adults had a smaller range of motion for shoulder and elbow flexion and forearm pronation compared with the controls. The analysis of functional tasks represents an important measure for the evaluation of dyskinetic movements and permits the quantitative characterization of upper limb impairment in adults with DCP.