A kinematic study of the reach to grasp movement in a subject with hemiParkinson's disease.

The kinematic organization of a reach to grasp movement in a left hemiParkinson subject is compared to that of a control subject. Subjects used the right and left limbs to reach 15, 27 or 40 cm for the grasp of cylinders of 0.7 or 8 cm diameter. In general, the kinematics of the affected limb of the hemiParkinson subject differed from that of the unaffected limb. However, for both arms the hemiParkinson subject showed a delay in the onset of the manipulation component. The subtle dysfunction in the activation of near-simultaneous or sequential movements is thus bilateral, despite unilateral clinical symptomatology.