Upper Arm Training With Armeo Spring for Stroke (Armeo Stroke)

• Change in Grip Strength from Baseline [ Time Frame: Baseline, 10 weeks ] [ Designated as safety issue: No ]
  
• Change in Box and Block Test score from Baseline [ Time Frame: Baseline, 10 weeks ] [ Designated as safety issue: No ]
  
• Change in Graded Wolf Motor Function Test score from Baseline [ Time Frame: Baseline, 10 weeks ] [ Designated as safety issue: No ]
  

By using the Armeo system, the investigators hope to achieve repetitive training of reach, grasp, and release in an engaging environment that can be adapted to individual capabilities, and to enable stroke survivors whose motor weakness may have excluded them from performing repetitive therapy tasks, to participate in this study.The Armeo system is an adjustable arm orthosis that has received FDA 510k exemption. It passively counterbalances the weight of the arm, thereby reducing the effort required by the paretic arm to overcome gravity. The device is able to augment feedback through a virtual environment (i.e. computer games). The tasks presented in the virtual environment are designed to achieve functional movements, i.e. the subject has to perform tasks such as reaching for objects as part of the game.

The ability to reach and grasp is a necessary component of many daily-life functional tasks. Impaired reach and grasp following strokes result in the recruitment of compensatory measures such as increased use of the trunk to transport the hand.

As an end-effector, the grip sensor provides a point of attachment, compared to the glove, in which the hand is free. The posture of the hand, range of movement, joint adaptations, movement pattern and kinematics are likely to be affected by a free or fixed end-effector. In this study, the investigators would like to compare the efficacy of training with both end-effectors. The investigators will also compare efficacy of these 2 end-effectors in high-functioning vs low-functioning hemiparetic subjects.