Wrist splint effects on muscle activity and force during a handgrip task

Area of Science:

• Biomechanics
• Occupational Health
• Rehabilitation Engineering

Background:

• Wrist splints are frequently used to limit motion and support the wrist during rest.
• The theoretical benefit of splinting is reduced wrist extensor muscle activity through joint stabilization.
• Their use in the workplace during active tasks is common but their efficacy is debated.

Purpose of the Study:

• To investigate the effect of wrist splints on forearm muscle activity during gripping tasks.
• To determine if splinting alters muscle activation patterns under varying grip efforts and wrist postures.

Main Methods:

• Ten healthy volunteers participated in a study involving randomized gripping trials with and without wrist splints.
• Surface electromyography (EMG) was used to measure activity in six forearm muscles.
• Trials included three wrist postures and four grip efforts, ranging from holding to maximal grip.

Main Results:

• Splinting significantly reduced flexor and extensor carpi radialis activity (<1% MVE) during low-level gripping.
• However, at maximal grip efforts, splint use significantly increased extensor muscle activity (7.9-23.9% MVE).

Conclusions:

• Wrist splints may support the wrist against external loads during low-to-moderate grip forces.
• Splinting appears counterproductive during maximal gripping efforts, increasing extensor muscle activity.
• Wrist bracing should be reserved for periods of minimal to light activity, not heavy tasks.