Design of a Dynamic Armrest MechanismBy Ault, Holly K.; Hoffman, Allen H.; Manrique, Lisette; RESNA 26th International Annual Conference 2003,
Publication Date: 2003
Paper discusses the design and development of an armrest attachment for a Mountain Man Bi-Ski from FFS Dual Ski in Bozeman, Montana. The Mountain Man Bi-Ski consists of a rigid molded fiberglass seat attached to two skis. People can use either hand-held outriggers or fixed outriggers and a handlebar attached to the ski. When the ski is properly fitted to the user, the device is precisely balanced, allowing even small movements to control the behavior of the ski. An individual with athetoid cerebral palsy had been using a Mountain Man Bi-Ski at various ski resorts throughout New England on a regular basis. The individual had no functional use of his extremities, and his arms were usually restrained to control his spasticity. When using the Mountain Man Bi-Ski, he used the fixed outriggers. In the past, his hands had been secured to the handlebars using duct tape, which posed a safety problem if had to be quickly removed from the device. Thus, an adaptive armrest mechanism was designed by a group of students in an introductory mechanical engineering design class. The armrest consisted of two molded arm troughs, each attached to a spring-loaded linear slide. The slide was mounted on blocks, which were spaced 5 inches apart on a piece of PVC tubing that fit over the device’s handlebars. The prototype mechanism allowed the user to have control over the ski through a combination of slight torso motion and elbow flexion. Side-to-side balance and control were achieved through head motions. After testing the mechanism, the user reported improvements in control and maneuverability of the ski. Minor adjustments in the position and orientation of the armrest were requested to further increase the user’s comfort.
Assistive Products Discussed: DOWNHILL SIT-N-SKI
Published by: Rehabilitation Engineering & Assistive Technology Society of North America (RESNA) (Website:http://www.resna.org)