The effect of repeated measurements using an upper extremity robot on healthy adults.

We are expanding the use of the MIT-MANUS robotics to persons with impairments due exclusively to orthopedic disorders, with no neurological deficits. To understand the reliability of repeated measurements of the robotic tasks and the potential for registering changes due to learning is critical. Purposes of this study were to assess the learning effect of repeated exposure to robotic evaluations and to demonstrate the ability to detect a change in protocol in outcome measurements. Ten healthy, unimpaired subjects (mean age = 54.1 +/- 6.4 years) performed six repeated evaluations consisting of unconstrained reaching movements to targets and circle drawing (with and without a visual template) on the MITMANUS. Reaching outcomes were aiming error, mean and peak speed, movement smoothness and duration. Outcomes for circle drawing were axis ratio metric and shoulder- elbow joint angles correlation metric (was based on a two-link model of the human arm and calculated hand path during the motions). Repeated-measures ANOVA (p < or = .05) determined if difference existed between the sessions. Intraclass correlations (R) were calculated. All variables were reliable, without learning across testing sessions. Intraclass correlation values were good to high (reaching, R > or =.80; circle drawing, R > or =.90). Robotic measurement ability to differentiate between similar but distinct tasks was demonstrated as measured by axis ratio metric (p < .001) and joint correlation metric (p = .001). Outcome measures of the MIT-MANUS proved to be reliable yet sensitive to change in healthy adults without motor learning over the course of repeated measurements.

Short-duration robotic therapy in stroke patients with severe upper-limb motor impairment.

Chronic motor deficits in the upper limb (UL) are a major contributor to disability following stroke. This study investigated the effect of short-duration robot-assisted therapy on motor impairment, as measured by clinical scales and robot-derived performance measures in patients with chronic, severe UL impairments after stroke. As part of a larger study, 15 individuals with chronic, severe UL paresis (Fugl-Meyer < 15) after stroke (minimum 6 mo postonset) performed 18 sessions of robot-assisted UL rehabilitation that consisted of goal-directed planar reaching tasks over a period of 3 weeks. Outcome measures included the Fugl-Meyer Assessment, the Motor Power Assessment, the Wolf Motor Function Test, the Stroke Impact Scale, and five robot-derived measures that reflect motor control (aiming error, mean speed, peak speed, mean:peak speed ratio, and movement duration). Robot-assisted training produced statistically significant improvements from baseline to posttreatment in the Fugl-Meyer and Motor Power Assessment scores and the quality of motion (quantified by a reduction in aiming error and movement duration with an increase in mean speed and mean:peak speed ratio). Our findings indicate that robot-assisted UL rehabilitation can reduce UL impairment and improve motor control in patients with severe UL paresis from chronic stroke.

Robotic upper-limb neurorehabilitation in chronic stroke patients.

This pilot study tested the effectiveness of an intense, short-term upper-limb robotic therapy for improvement in motor outcomes among chronic stroke patients. We enrolled 30 subjects with upper-limb deficits due to stroke of at least 6 mo duration and with a Motor Power Assessment grade of 3 or less. Over 3 wk, 18 sessions of robot-assisted task-specific therapy were delivered with the use of a robotic exercise device that simulates a conventional therapy known as skateboard therapy. Primary outcome measures included reliable, validated impairment and disability measures of upper-limb motor function. Statistically significant improvements were observed for severely impaired participants when we compared baseline and posttreatment outcomes (p < 0.05). These results are important because they indicate that improvement is not limited to those with moderate impairments but is possible among severely impaired chronic stroke patients as well. Moderately and severely impaired patients in our study were able to tolerate a massed-practice therapy paradigm with intensive, frequent, and repetitive treatment. This information is useful in determining the optimal target population, intensity, and duration of robotic therapy and sample size for a planned larger trial.