Task-Dependent Bimanual Coordination After Stroke: Relationship With Sensorimotor Impairments.

OBJECTIVES

To determine (1) bimanual coordination deficits in patients with stroke using 3-dimensional kinematic analyses as they perform naturalistic tasks requiring collaborative interaction of the 2 arms; and (2) whether bimanual coordination deficits are related to clinical measures of sensorimotor impairments and unimanual performance of the paretic arm.

DESIGN

Case-control study.

SETTING

Rehabilitation hospital research institute.

PARTICIPANTS

Participants (N=24) were patients with unilateral chronic stroke (n=14) and age-matched controls (n=10).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Temporal coordination between the 2 hands as participants performed (1) a symmetric task: reach to pick up a box using both hands; and (2) an asymmetric task: open a drawer with 1 hand to press a button inside with the other hand.

RESULTS

During the symmetric task, patients and controls showed preserved temporal coupling while transporting the hands to the box. However, on reaching the box, patients demonstrated an impaired ability to cooperatively interact their 2 arms for an efficient pickup. This led to significantly longer pickup times compared with controls. Pickup time positively correlated with proprioceptive deficits of the paretic arm. During the asymmetric task, patients had a longer time delay between drawer opening and button pressing movements than controls. The deficits in asymmetric coordination did not significantly correlate with sensorimotor impairments or unimanual paretic arm performance.

CONCLUSIONS

Bimanual coordination was impaired in patients poststroke during symmetric and asymmetric bimanual tasks that required cooperative interaction between the 2 arms. While the proprioceptive system contributes to symmetric cooperative coordination, commonly tested measures of paretic arm impairment or performance, or both, do not strongly predict deficits in bimanual coordination.