The study authors indicate that grip size changes the impact forces, but that is unlikely to contribute to overuse injuries and tendonitis. They go on to recommend that players use the grip size they find most comfortable.
The study followed ten male and six female NCAA tennis players - none of whom had any history of elbow problems. The players then performed one-hand backhand strokes using identical tennis rackets with three different grip sizes. Researchers then measured the firing patterns of forearm muscles during the swings. They found no difference in the firing patterns of the muscles with different grip sizes.
The findings further support previous research that finds improper form is one of the biggest causes of tennis elbow. This reinforces the recommendation that players with elbow pain work more on their tennis swing mechanics and stroke instead of changing equipment.
For more about proper tennis technique, visit Tennis.About.com.