Coordination of upper and lower limb segments: deficits on the ipsilesional side after unilateral stroke

Abstract.

Coordination of the ipsilateral limbs was studied in unilateral stroke patients and a control group of healthy age-matched controls. Cyclical single-limb movements of the forearm and lower leg as well as their coordination, with the segments moving either in the same (isodirectional) or in different directions (nonisodirectional), were investigated under normal vision and blindfolded conditions. Findings revealed that stroke patients experienced difficulties with coordination of the limb segments on the ipsilesional side and this effect was more pronounced during nonisodirectional than during isodirectional coordination. In addition, cycle durations were larger and movement amplitudes shorter in stroke patients as compared to controls. Overall, the present findings clearly demonstrated motor control deficits in stroke patients on the so-called "unaffected side." The availability of normal vision did not alleviate these deficits. Therefore, the more general implication of the present findings appears to be that interlimb coordination is a complex function, requiring the integrity of both hemispheres. Comparison of the left- and right-hemispheric stroke groups revealed that patients with a left-hemisphere lesion tended to be more variable in performing the more difficult nonisodirectional pattern than patients with a right-hemisphere lesion. This possibly hints at a more pronounced involvement of the left hemisphere in the organization of ipsilateral coordination. The spatiotemporal features of movement (cycle duration, amplitude), however, did not differ between both stroke groups.