Reduced skilfulness of arm motor behaviour among motor stroke patients with good clinical recovery: does it indicate reduced automaticity? Can it be improved by unilateral or bilateral training? A kinematic motion analysis study.

Functional cortical reorganisation had been demonstrated to accompany recovery from motor stroke. In agreement with a previous study, quantitative kinematic analysis of aimed movements in 14 almost completely recovered hemiparetic stroke patients and 14 healthy control subjects indicated a reduced skilfulness of both the more ballistic initial movement phase and the more feedback-guided late homing-in phase of aimed movements. By means of two dual motor tasks it was further investigated whether the reduced skilfulness of patients was due to an increased attentional demand and thus a reduced automaticity of motor control. Interference effects by dual tasks, however, were similar for patients and control subjects. Thus, the notion of reduced automaticity could not be supported empirically, and reduced skilfulness seemed rather related to residual pyramidal motor deficits. By means of a repetitive daily training for 1 week based on the Arm Ability Training approach, patients were able to reduce their performance deficits in both movement phases significantly. Whether patients practised with the affected arm or simultaneously with both the affected and non-affected arm only marginally modified outcome, unilateral training being slightly more efficacious. These findings demonstrate that even clinically minor residual motor deficits can be improved by a structured training for the affected arm.