This study aimed to clarify the effects of parachute swimming on upper limb muscle activity and its immediate impact on muscle activity during free swimming without resistance. Eight competitive swimmers performed 15-m sprint front-crawl swims in the following order: (1) free swimming, (2) parachute swimming, and (3) free swimming after parachute swimming. The final 10-m time, video footage, and surface EMG data from six muscles were analysed. The 10-m time increased during parachute swimming, but no improvement was confirmed in the subsequent free swimming. During parachute swimming, the pull phase was extended and the recovery phase shortened. EMG analysis showed no increase in muscle activity during parachute swimming compared to free swimming. However, changes in the activation onset of the triceps brachii and middle deltoid were observed across the trials, and a reduction in flexor carpi ulnaris activity during the recovery phase was found immediately after parachute swimming.

This study aimed to examine the relationship between throwing velocity and shoulder range of motion and muscle strength in collegiate male water polo players with and without shoulder pain. Twenty-one players from a Division 2 university league team were divided into a pain group (9 participants) and a non-pain group (12 participants). The relationship between throwing velocity, shoulder range of motion, and muscle strength was assessed. In the non-pain group, the difference in internal rotation strength between the throwing and non-throwing sides significantly correlated with throwing velocity (r = 0.60, p = 0.04). The pain group had a significantly greater external rotation and internal rotation range of motion in the throwing shoulder compared to the non-pain group (mean difference: 15.02 and 15.83, p = 0.02 and 0.04, respectively). These findings suggest that improving internal rotation strength and monitoring shoulder rotation range of motion are crucial for conditioning collegiate water polo players, with consideration for shoulder pain.