Simulated Home Therapy Program for the Hand After Stroke

Stroke survivors with chronic hemiparesis of the upper extremity undertook 18 one-hour training sessions over a 6-week period. Participants received occupational therapy focusing on grasp-and-release using a task-oriented protocol developed at the Rehabilitation Institute of Chicago by Dr. Mary Ellen Stoykov. Over 90% of all repetitions performed during each session were focused on functional activities, as opposed to active exercise. The skills and strategies developed in therapy were then implemented into activities identified as goals by the participant, such as donning socks. Difficulty of the task, activity, or exercise was progressed for each participant to provide optimal challenge to enhance skill.

Subjects were assigned to one of two groups by casting lots. One group (VAEDA Glove) performed all tasks while wearing a custom Voice And EMG-Driven Actuated glove, the VAEDA Glove. The other group (No-Glove) performed the same types of tasks without use of the VAEDA Glove. The VAEDA Glove is a portable active-assistance glove, designed to assist digit extension in order to allow repeated practice of specified tasks. The glove contains cables traversing the dorsal side of the digits in order to provide extension and resist flexion. Forces are transmitted through the cables from a servomotor located remotely to the digits. The servomotor controls torque or displacement in the cable. Along the digits, the cables traverse through custom plastic blocks, which serve both to guide the cable and to prevent joint hyperextension.

The VAEDA Glove can be controlled with up to 3 channels of electromyography (EMG). For this study, electrodes were placed above flexor digitorum superficialis (FDS) and extensor digitorum communis (EDC). The group using the J-Glove could receive assistance during hand opening, but only if appropriate EMG activity was detected. The EDC EMG activity had to reach a prescribed threshold before extension assistance would be provided. Similarly, FDS EMG activity had to surpass a threshold level during hand closing before the user was allowed to flex the digits. Feedback of muscle activity was available to the user through a custom graphical user interface.

Inclusion criteria

• chronic upper extremity hemiparesis subsequent to stroke (minimum of 6 months post-stroke)
• moderate hand impairment classified as Stage 4 on the Chedoke McMaster Stroke Assessment

Exclusion criteria

• anti-spasticity medications/injections taken less than 6 month prior to enrollment
• contractures greater than 20 degrees
• inability to follow single-step commands
• significant upper extremity pain (self-reported pain of greater than 6 on a 10-point scale)