Concentric exercise-induced fatigue of the shoulder impairs proprioception but not motor control or performance in healthy young adults

Objectives: To investigate the effect of concentric fatigue on proprioception, motor control and performance of the shoulder in healthy young adults. Design: Test-retest experimental design. Setting: Human performance laboratory. Participants: 20 healthy adults. Main outcome meausure(s): Proprioception was assessed using the joint repositioning sense (JRS) and the threshold to detection of passive movement (TTDPM). Motor control was assessed using the Y-balance Upper Quarter test (YBT-UQ) and performance using the Athletic Shoulder test (ASH test). All tests were conducted before and immediately after fatigue intervention (CON/CON protocol). Results: Following fatigue, absolute angular error (AAE) was significantly increase by 160.27 %. Moreover, there was a significant increase (48.41 %) in TTDPM after fatigue. Furthermore there was no significant differences in motor control and performance before and after fatigue intervention. Conclusions: Since muscular fatigue negatively affects shoulder proprioception, it is essential to assess proprioception before and after fatigue to detect any dysfunctions that may arise as a result of fatigue. To address these dysfunctions, it is recommended to engage in proprioceptive exercises under situations of fatigue in order to enhance the sensitivity of the mechanoreceptors.