Influence of Posture-Cuing Shirt on Tennis Serve Kinematics in Division III Tennis Players

Objective: Injuries to the shoulder complex are common in overhead athletes, often related to kinematics of the shoulder complex. This study evaluated the influence of a posture-cuing shirt on internal rotation velocity of the shoulder during a tennis swing and to determine this influence on shoulder external rotation position. Methods: Nine healthy competitive college tennis players from a Division III college participated in this study. High speed motion capture allowed for 3-D analysis of shoulder kinematics during a tennis serve. Two conditions were evaluated while the athletes performed a high velocity tennis serve: standard tennis shirt and a posture-cuing shirt. Results: Shoulder internal rotation velocity increased when wearing the PC shirt. Peak internal rotation velocity increased from 960.61 degrees/second + 93.24 degrees/second to 1217.96 degrees/second + 155.01 degrees/second (t = -1.76, p = 0.058). Internal rotation velocity at the time of impact increased from 765.18 degrees/second + 95.48 degrees/second) to 900.54 degrees/second + 105.33 degrees/second) (t = -1.50, p = 0.086). Shoulder maximum external rotation did not differ between the two conditions, at 172.00 degrees + 2.92 degrees and 170.89 degrees + 3.70 degrees (t = 0.325, p = 0.754). Conclusions: Wearing a posture-cuing shirt has the potential to alter shoulder kinematics during an overhead sport activity such as tennis. Internal rotation velocity improved while wearing this shirt, while shoulder external rotation position did not change. It is not known if these improvements can influence injury risk