Context: The glenohumeral (GH) joint has been frequently labelled as the joint that sacrifices stability for the sake of mobility (Allegrucci, Whitney & Irrgang, 1994). Previous research has suggested that fatigue has an impact on the external rotation (ER) and internal rotation (IR) shoulder ratio strength, especially the external rotators in overhead athletes (Ellenbecker & Mattalino, 1997). Objective: To determine the effect of fatigue on ER and IR ratio muscle strength of the shoulder joint in hypermobile and non-hypermobile individuals. Pain and disability of the shoulder in relation to joint hypermobility was also investigated. Design: Pre-test and post-test, independent groups design. Participants: 22 swimmers from the University of Chichester, age (19.95years ± 1.00), height (176cm ± 6.73) and weight (72.4kg ± 12.38). Method: Participants were split into two groups; hypermobile and non-hypermobile, which was determined by the Beighton score. Following this, participants filled out a SPADI questionnaire and undertook a 150m freestyle warm up. ER and IR shoulder muscle strength was carried out using a hand-held dynamometer (Commander Muscle Tester, JTECH Medical, Midvale, USA). Both groups then undertook the fatiguing protocol where they were instructed to swim freestyle at a race pace until a score of 17 on the Borg scale was reached. Post muscle strength testing was carried out immediately after the fatiguing protocol. Results: No significant differences were identified between hypermobile and non-hypermobile groups, regardless of dominant or non-dominant shoulders: Dominant: (F (1,20) = 0.025, ηP2= 0.001, p=0.877, p>0.05) and Non-dominant: (F (1,20) = 0.054, ηP2= 0.021, p=0.518, p>0.05). A significant difference was identified over time on the dominant side: (F (1,20) = 4.576, ηP2= 0.186, p=0.045, p<0.05), but not on the non-dominant side: (F (1,20) = 0.054, ηP2= 0.003, p=0.819, p>0.05). Conclusion: In this case, fatigue had no effect on rotation ratio of the shoulder joint in hypermobile and non-hypermobile swimmers. Implications: It is important that clinicians understand the relationship between fatigue and pain, and how to manage this within training and rehabilitation.