Shoulder Torque Production and Muscular Balance after Long and Short Tennis Points

Tennis is an asymmetric sport characterized by a systematic repetition of specific movements that may cause disturbances in muscular strength, power, and torque. Thus, we assessed (i) the torque, power, ratio production, and bilateral asymmetries in the shoulder's external and internal rotations at 90 and 180 degrees/s angular velocities, and (ii) the point duration influence of the above-mentioned variables. Twenty competitive tennis players performed external and internal shoulder rotations; an isokinetic evaluation was conducted of the dominant and non-dominant upper limbs before and after five and ten forehands. A higher torque production in the shoulder's internal rotations at 90 and 180 degrees/s was observed for the dominant vs. non-dominant sides (e.g., 63.1 +/- 15.6 vs. 45.9 +/- 9.8% and 62.5 +/- 17.3 vs. 44.0 +/- 12.6% of peak torque/body mass, p < 0.05). The peak torque decreased only after ten forehands (38.3 +/- 15.8 vs. 38.2 +/- 15.8 and 39.3 +/- 16.1 vs. 38.1 +/- 15.6 Nm, respectively, p < 0.05), but without impacting speed or accuracy. Unilateral systematic actions of tennis players caused contralateral asymmetries, evidencing the importance of implementing compensatory training. The forehand kinematic assessment suggests that racket and wrist amplitude, as well as speed, are important success determinants in tennis.

Automated summary

Tennis is an asymmetric sport that can affect muscular strength, power, and torque due to the systematic repetition of specific movements. This study assessed the torque, power, ratio production, and bilateral asymmetries in shoulder rotations of tennis players, and found that unilateral actions caused contralateral asymmetries, highlighting the importance of implementing compensatory training.