Effectiveness of exercise programs for swimmer’s shoulder prevention in competitive swimmers: a randomized controlled trial.

Verify the effectiveness of two 12-week preventive programs on the shoulder rotators' peak torque, and conventional and functional ratios. 

A care provider and participants blinded, parallel, randomized controlled trial with 30 competitive swimmers divided into 3 groups was performed. Twice a week, over 12 weeks, the 2 experimental groups carried out 5 strength exercises where the only difference was executing the program with weights or elastic bands.  In contrast, the control group performed a sham intervention. Before (T0) and after (T1) this procedure, concentric and eccentric peak torque of internal and external rotators of the non-dominant shoulder was assessed through an isokinetic dynamometer Biodex System 3, at 60°/s, 120°/s, and 180°/s. After that, the conventional concentric ratio and the functional ratio were calculated. The collected data was previously filtered, windowed, and processed using the Acqknowledge 4.1 software. An intra-group analysis between T0-T1 was done, applying a paired sample T-test or a Wilcoxon test. 

Regarding the rotator's peak torque, there was one increase (p = 0.028) in the weight program group, one drop (p = 0.029) in the elastic band program group, and 7 drops (p ≤ 0.05) in the control group. After 12 weeks, rotator's peak torque of the swimmers who completed the prevention programs come closer to the conventional and functional rotational ratios to normative prevention injury values for this population, while the control group had the opposite result. 

The absence of a preventive program reduces strength in the internal and external shoulder rotators. Implementing a 12-week preventive program for swimmer's shoulder minimizes the progressive shoulder rotational imbalance over the season in competitive swimmers. 

Implementing strength programs with few exercises performed out of the water in an open kinetic chain is an effective physiotherapy intervention to minimize modifiable musculoskeletal risk factors for the swimmer’s shoulder with a credible impact on the number and severity of this injury throughout the season.