The effects of swimming fatigue on shoulder strength, range of motion, joint control, and performance in swimmers

Purpose: To investigate the effects of training induced fatigue on shoulder strength, ROM, joint position sense, and stroke length in elite competitive swimmers. Methods: Seventeen national level swimmers performed maximum isometric strength (internal and external rotation), ROM, and joint position sense tests before and after a fatiguing 8 x 100 m training set. Stroke length, heart rate, blood lactate and blood glucose levels were recorded throughout. Results: Peak blood lactate, blood glucose levels, and heart rate increased significantly (P<0.001) post training confirming fatigue. Reductions were observed in stroke length of both arms (P<0.001), external rotation range of motion (P<0.001, 5.29, Right shoulder; P = 0.04, -3.18 degrees, Left shoulder) and joint position sense in their dominant (breathing side) arm (P = 0.03). Conclusions: This investigation revealed a reduction in stroke length across both arms and also an arm bias in swimming whereby a greater reduction in both external rotation range and joint position sense was observed in the dominant arm when fatigued. This has highlighted a relationship between fatigue and potential mechanism of shoulder pathology in swimmers. (C) 2016 Elsevier Ltd. All rights reserved.