The effect of tennis racket grip size on forearm muscle firing patterns.

Background: Inappropriately sized tennis racket grip is often cited in the popular media as a risk factor for overuse injuries about the forearm and elbow. Currently, a hand measurement technique developed by Nirschl is commonly used by tennis racket manufacturing companies as the method for determining a player's "recommended" grip size.

Hypothesis: Quarter-inch changes from that recommended by Nirschl in tennis racket grip size will have no significant effect on forearm muscle firing patterns.

Study Design: Controlled laboratory study.

Methods: Sixteen asymptomatic Division I and II collegiate tennis players performed single-handed backhand ground strokes with rackets of 3 different grip sizes (recommended measurement, undersized (1/4) in, and oversized (1/4) in). Fine-wire electromyography was used to measure muscle activity in extensor carpi radialis longus and brevis, extensor digitorum communis, flexor carpi radialis, and pronator teres. Repeated-measure analysis of variance was used for within-group comparisons, comparing different grips in specified phases for backhand ground strokes (P
Results: There were no significant differences in muscle activity between small, recommended, or big grips in any muscle tested.

Conclusion: Based on these findings, tennis racket grip size (1/4) in above or below Nirschl's recommended measurement does not significantly affect forearm muscle firing patterns.

Clinical Relevance: Alterations in tennis racket grip size within (1/4) in of Nirschl's recommended sizing do not have a significant effect on forearm muscle activity and therefore may not represent a significant risk factor for upper extremity cumulative trauma, such as lateral epicondylitis.