The Electric Elevation Assist and Spacticity Control Arm (EEASCA) is designed as an augmentative mechanical arm support for an 11-year old boy who has dystonic cerebral palsy with choreoathetoid movement. A previous arm support system was not comfortable, and movement was restricted to only the horizontal plane. A device that would restrict the consumer’s spasticity, but allow him to raise and lower his arm so he is able to perform day-to-day tasks is needed. The device had to be able to be removed and attached to the client’s wheelchair easily and quickly. The EEASCA provides a comfortable restraint system that restricts the user’s spasticity, but allows him to control elbow flexion so that he can perform such tasks as eating, brushing his teeth, and other hygienic activities.
The EEASCA had to restrain posterior abduction of the humerus at a force of 40 to 120 pounds. To accomplish daily tasks that involve hand-to-mouth motion of his right arm, augmentation of the device had to allow for 0º-110º degrees flexion of the elbow, 50º-60º degrees internal rotation of the shoulder, 30º-45º degrees flexion, abduction of the humerus, and a lifting force of 25 pounds. In addition, the device had to restrain his dystonic spasms of 40 to 120 pounds. The device is controlled by the user, and any electrical and mechanical components had to be properly installed. The final EEASCA design incorporates an AC linear actuator to provide the desired range of motion, a foot control for the user to control movement, and a control box to convert AC to DC power. These devices were donated by LINAK (Louisville, KY), and were chosen based on size, weight, availability, appearance, and desired performance. The LINAK linear actuator was wired to the control box. Snap-connectors and heat-shrink tubing were added to secure the line. The original distal joint of the arm support was removed, and an aluminum conduit was used to fix the arm support segments into a set position. Locking the arm at this joint functions in spasm control and also provides a stable mounting position for the actuator. This positioning allows the user’s arm to be relaxed, hanging slightly anterior to his body, from where the linear actuator can raise his hand to his mouth in a comfortable and natural manner. Steel bushings were placed in the piston rod eyes to accommodate for diameter size differences between the eyes and the mounting brackets. A hole was drilled as close to the proximal joint as possible to allow for full extension of the actuator piston. A conduit hanger was then bolted at the hole’s location to allow for attachment of the stationary piston rod eye. The forearm support was adjusted to allow for the proper pivot angle, and a stainless steel bolt was inserted through a mounting flange to attach the movable piston rod eye. Vinyl bushings were then used to prevent lateral movement and a stop-pinion was removed to prevent overshoot complications. The linear actuator, control box and foot switch were donated, resulting in a total cost of $96.