A comparison of functional and impairment-based robotic training in severe to moderate chronic stroke: a pilot study

Abstract

Objective: To compare the outcome of training the functional movement of transport of the arm and grasping an object with the alternative of training the transport of the arm in isolation.

Design: Pretest-posttest comparison.

Setting: Rehabilitation hospitals, outpatient care.

Participants: Volunteer sample of forty-seven persons with persistent hemiparesis from a single, unilateral stroke within the past one to five years.

Intervention: Robotic therapy 3 x/week for 6 weeks for the paretic upper limb consisted of either a) sensorimotor, active-assistive impairment-based exercise during repetitive planar reaching tasks, or b) a "free-hand" approach, in which the robot assisted subjects employing the sensorimotor active-assistive exercise to transport the hand to a series of targets, where it stopped to allow the person to interact with actual objects (functional approach 1), or c) transport and manipulation, in which the robot assisted subjects employing active-assistive exercise during repetitive planar reaching tasks while grasping a simulated object and releasing it at the target or followed by grasp and release of a simulated object (functional approach 2).

Primary outcome measure: Fugl-Meyer Assessment.

Results: All three groups improved from pre- to post-treatment with the sensorimotor impairment based approach demonstrating the best outcome of the three approaches.

Conclusions: Short-term, goal-directed robotic therapy can significantly improve motor abilities of the exercised limb segments in persons with chronic stroke, but contrary to expectation, training both the transport of the arm and manipulation of an object (functionally-based approaches) did not confer any advantage over training solely transport of the arm (impairment-based approach).

Figure 1

Impairment and Functional Based Approaches for Robotic Therapy. Top left photo shows a patient receiving impairment training that consisted of a series of reaching movements to targets shown on a computer screen (Group A). Top right photo shows one of us (Dr. Fasoli) demonstrating the “free-hand” approach in which the robot assisted during reaching movements to actual targets and the patient manipulated actual objects (Group B). Bottom left photo shows a patients exercising reaching while grasping a virtual token to a target and then releasing the token. Bottom right plot shows an example of the grasp force during this reaching movement.