Evaluation and Intervention in the Paretic Upper Extremity Following Hemiparetic Stroke using the ACT 3D System

The effect of gravity on the expression elbow/shoulder synergy patterns results in discoordination during movements following stroke. This is believed to be related to the shoulder abduction torques generated when lifting the arm against gravity, which results in a concurrent elbow flexion (i.e., the flexion synergy). The Arm Coordination Training 3-D (ACT ) robotic system is a novel way of recording movement patterns while a subject generates varying amounts of shoulder abduction torque. This system is used to show increased shoulder abduction forces reduce a stroke subject's available work area in a way that is consistent with the flexion synergy. The system can also be used in interventions that target reducing this abnormal synergy; a case study is presented