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Wrist tendon forces with respect to forearm rotation
Leela D Farr1, Frederick W Werner, Michael L McGrattan
1Department of Orthopedic Surgery, SUNY Upstate Medical University, Syracuse, NY 13210, USA.
The Journal of Hand Surgery
|December 11, 2012
Summary
Forearm supination minimizes wrist tendon forces during motion initiation, aiding recovery from carpal injuries and distal radius fractures. This position is ideal for early active rehabilitation to reduce deforming forces.
Area of Science:
- Biomechanics
- Orthopedic Surgery
- Rehabilitation Medicine
Background:
- Early motion therapy is crucial for reducing wrist stiffness post-carpal injury or distal radius fracture.
- Minimizing radioulnar carpal joint reaction force is key to effective rehabilitation.
Purpose of the Study:
- To identify the forearm position that requires the least wrist tendon forces for initiating wrist motion.
- To reduce deforming forces during early stages of recovery.
Main Methods:
- Eight fresh-frozen cadaver forearms were tested using a wrist and forearm motion simulator.
- Wrist flexion-extension and radioulnar deviation motions were analyzed in supination, pronation, and neutral forearm positions.
- Forces in five wrist tendons were continuously recorded during simulated motions.
Main Results:
- Peak wrist extensor and flexor tendon forces were significantly lower in the forearm supinated position compared to neutral or active forearm rotation.
- Specific tendons, like extensor carpi radialis longus and flexor carpi ulnaris, showed reduced forces in supination.
- Radioulnar deviation also demonstrated reduced peak forces in supination versus pronation.
Conclusions:
- The static forearm supinated position results in the lowest peak wrist tendon forces.
- Initiating active rehabilitation with the forearm in supination can minimize deforming forces on fresh carpal injuries and distal radius fractures.
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