Evaluation of a wrist orthosis on lofstrand crutch-assisted gait

Lofstrand, or forearm, crutches are a common assistive mobility device for those with functional impairments. However, repeated loading of the wrist and palmar region and continual hyperextension of the wrist during Lofstrand crutch usage may cause wrist strain, pain, and secondary injuries such as carpal tunnel syndrome. In order to reduce risk of injury, a novel wrist orthosis was developed with the intent of improving wrist posture and reducing/redirecting palmar loads from the carpal tunnel region to the adductor pollicis area. Dominanthand palmar loads and wrist extension angles of 10 healthy, able-bodied subjects were measured during swing-through Lofstrand crutch-assisted gait to demonstrate the orthosis effectiveness. Each subject performed 10 trials each with and without the orthosis. An enhanced understanding of the effects of the wrist orthosis on kinematics and palmar loading was gained through this study. Results indicated a significant decrease in maximum palmar force, contact area, and wrist extension when using the orthosis. Palmar loads were observed to be redirected toward the adductor pollicis when using an orthosis during Lofstrand crutch-assisted gait. Ultimately, this device was effective in redistributing palmar loads with the potential to reduce pain and risk of carpal tunnel syndrome in long-term Lofstrand crutch users.