The Kinematics of 3D Arm Movements in Sub-Acute Stroke: Impaired Inter-Joint Coordination is Attributable to Both Weakness and Flexor Synergy Intrusion.

Weakness and synergy intrusion contribute to motor deficits in the sub-acute post-stroke period. An abnormal FMA score cannot be assumed to be due to synergy intrusion. Careful kinematic analysis of naturalistic movements is required to better characterize the contribution of negative and positive signs to upper limb impairment after stroke.