Motor dysfunction of the "non-affected" lower limb: a kinematic comparative study between hemiparetic stroke and total knee prosthesized patients.

In patients with hemispheric stroke, abnormal motor performances are described also in the ipsilateral limbs. They may be due to a cortical reorganization in the unaffected hemisphere; moreover, also peripheral mechanisms may play a role. To explore this hypothesis, we studied motor performances in 15 patients with hemispheric stroke and in 14 patients with total knee arthroplasty, which have a reduced motility in the prosthesized leg. Using the unaffected leg, they performed five superimposed circular trajectories in a prefixed pathway on a computerized footboard, while looking at a marker on the computer screen. The average trace error was significantly different between the groups of patients and healthy subjects [F ((2,25)) = 7.9; p = 0.003]; on the contrary, the test time execution did not vary significantly. In conclusion, both groups of patients showed abnormal motor performances of the unaffected leg; this result suggests a likely contribution of peripheral mechanisms.