Abstract-This randomized, controlled, multisite Department of Veterans Affairs clinical trial assessed robot-assisted (RA) upper-limb therapy with the Mirror Image Movement Enabler (MIME) in the acute stroke rehabilitation setting. Hemiparetic subjects (n = 54) received RA therapy using MIME for either up to 15 hours (low-dose) or 30 hours (high-dose) or received up to 15 hours of additional conventional therapy in addition to usual care (control). The primary outcome measure was the FuglMeyer Assessment (FMA). The secondary outcome measures were the Functional Independence Measure (FIM), Wolf Motor Function Test, Motor Power, and Ashworth scores at intake, discharge, and 6-month follow-up. Mean duration of study treatment was 8.6, 15.8, and 9.4 hours for the low-dose, high-dose, and control groups, respectively. Gains in the primary outcome measure were not significantly different between groups at follow-up. Significant correlations were found at discharge between FMA gains and the dose and intensity of RA. Intensity also correlated with FMA gain at 6 months. The high-dose group had greater FIM gains than controls at discharge and greater tone but no difference in FIM changes compared with low-dose subjects at 6 months. As used during acute rehabilitation, motor-control changes at follow-up were no less with MIME than with additional conventional therapy. Intensity of training with MIME was positively correlated with motor-control gains.Clinical Trial Registration: ClinicalTrials.gov, NCT00223808, "Assisted Movement Neuro-rehabilitation: VA Multi-site Clinical Trial"; http://www.clinicaltrials.gov/ct2/show/NCT00223808

We evaluated a method for measuring abnormal upper-limb motor performance in post-stroke hemiparetic subjects. A servomechanism (MIME) moved the forearm in simple planar trajectories, directly controlling hand position and forearm orientation. Design specifications are presented, along with system performance data during an initial test of 13 stroke subjects with a wide range of impairment levels. Performance of subjects was quantified by measuring the forces and torques between the paretic limb and the servomechanism as the subjects relaxed (passive), or attempted to generate force in the direction of movement (active). During passive movements, the more severely impaired subjects resisted movement, producing higher levels of negative work than less-impaired subjects and neurologically normal controls. During active movements, the more severely impaired subjects produced forces with larger directional errors, and were less efficient in producing work. These metrics had significant test-retest repeatability. These motor performance metrics can potentially detect smaller within-subject changes than motor function scales. This method could complement currently used measurement tools for the evaluation of subjects during recovery from stroke, or during therapeutic interventions.

Reconstructive hand surgeries restore key pinch to individuals with pinch force deficits caused by tetraplegia. Data that define the magnitudes of force necessary to complete functional key pinch tasks are limited. This study aims to establish target pinch forces for completing selected tasks that represent a range of useful functional activities. A robot arm instrumented with a force sensor completed the tasks and simultaneously measured the forces applied to the task objects. Lateral pinch force requirements were calculated from these measured object forces. Pinch force requirements ranged from 1.4 N to push a button on a remote to 31.4 N to insert a plug into an outlet. Of the tasks studied, 9 of 12 required less than 10.5 N. These pinch force requirements, when compared to pinch forces produced by 14 individuals with spinal cord injuries (with and without surgical reconstruction of pinch), accurately predicted success or failure in 81% of subject trials. The prediction errors indicate a need to measure other factors such as pinch opening, force location, force direction, and proximal joint control.

Background Abnormal biomechanical loading has been identified as an associated risk factor of osteoarthritis in the wrist and hand. Empirical data to date are insufficient to describe the role of altered biomechanics in thumb carpometacarpal (CMC) arthritis. Questions/purposes This is a pilot study to evaluate motion analysis of the upper extremity while performing functional tasks. We wished to describe the in vivo kinematics of the thumb and hand in relation to the larger joints of the upper extremity in subjects without arthritis in functional positions at rest and while loading the CMC joint. If reproducible, we then planned to compare kinematics between these subjects and a subject with advanced thumb CMC arthritis.