Kinematic analysis of a functional and sequential bimanual task in patients with left hemiparesis: Intra-limb and interlimb coordination

Purpose. To characterise upper limb performance of each hand intra-limb coordination and interlimb coordination on a functional, sequential bimanual task in patients with left hemiparesis and age-matched controls. Method. Fourteen patients with left hemiparesis age: 60.01±9.09 years and 13 adults without neurological impairments age: 59.14±10.59 years were instructed to reach-to-grasp a jar with the affectedleft limb and to unscrew the jar cap with the unaffectedright limb. Reaching and grasping kinematics were analysed for intra-limb coordination and bimanual synchronisation and temporal correlation for interlimb coordination. Results. The patients showed significantly less efficient, less smooth, and less forceful movement and spent significantly more time for on-line error correction with the affected hand than the healthy controls. Interlimb coordination was disrupted at movement onset but was preserved at movement end in the hemiparetic patients. Conclusions. The major deficits of the left hemiparetic patients involved heavy reliance on feedback control with the affected hand, and poor bimanual coordination at movement onset, which might be specifically retrained during stroke rehabilitation. Preservation of interlimb coordination at movement end in stroke patients suggested that they retained flexibility in response to the impaired temporal performance of the affected hand to achieve the end goal.