The tennis stroke: an EMG analysis of selected muscles with rackets of increasing grip size.

The purpose of this study was to analyze the effect of different racket grip sizes on the muscle activity of the forearm and shoulder. Telemetry EMG was used to assess the muscle activity of the anterior deltoid and the forearm extensor muscles during the forehand and backhand strokes of tennis in a selected group of test subjects. The EMG activity of the subjects' anterior deltoid muscle and the forearm extensor muscle group was recorded with the subjects using racket grip sizes of 4 1/4, 4 1/2, 4 3/4 inches. A specific pattern of sequence phasing was seen in all subjects, and amplitude ratio between the muscles was constant. Changes in grip size demonstrated a change in amplitude of both the anterior deltoid and the forearm extensor muscle group.