Motor compensation and recovery for reaching in stroke patients.

OBJECTIVES: To examine the mechanisms of alternative strategies developed by stroke patients to compensate their motor impairment and their role in recovery. MATERIAL AND METHODS: The three-dimensional kinematics of the upper limb were quantified during unconstrained reaching movements in seven healthy individuals and in 15 stroke patients. Nine patients were followed-up. Individual observations were correlated with anatomical and functional brain imaging described elsewhere (Feydy et al. Stroke 2002;33:1610). RESULTS: Healthy subjects used mainly elbow extension and shoulder flexion, scaled to movement distance. Patients with hemiparesis because of stroke used different patterns of joint recruitment with different scaling rules. Patients with the greatest impairment compensated by recruiting extra degrees of freedom, particularly trunk bending. Improvement was because of a restoration towards a normal movement pattern (recovery) and/or to a reinforcement of compensation, which led to a poorer outcome. CONCLUSION: Individual behavioural data are necessary to discuss the mechanisms of functional improvement following stroke with respect to recovery and/or compensation