Objectives To assess if swimming practice results in changes in supraspinatus tendon thickness, acromiohumeral distance, and occupational ratio in shoulders of elite swimmers with and without a history of shoulder pain. Design Case‐Control study. Methods A convenience sample of fifty elite swimmers (14‐22 years) were recruited for this study. Groups were defined by the presence (history of pain, N = 37) or absence (pain free, N = 63) of significant interfering shoulder pain within the previous 6 months. The current study analyzed supraspinatus tendon thickness, acromiohumeral distance, and the occupational ratio, through the use of ultrasound. Measures were taken prior to swim practice; immediately after practice; and 6 hours post‐practice. Results No statistically significant difference in supraspinatus tendon thickness, acromiohumeral distance or ratio between shoulders with and without a history of pain were found at rest. Following a swimming practice, both shoulders with and without a history of pain had a significant increase in tendon thickness (0.27 & 0.17 mm; P ≤ .001 & <.001). The increase in thickness was significantly greater in the history of pain shoulders compared to pain‐free shoulders (P = .003). At 6‐hour post‐practice, the history of pain shoulders was still significantly thicker than their pre‐practice (rested) levels (P = .007). Despite changes in tendon thickness, the occupational ratio remained non‐significant between groups. Conclusion Shoulders with a history of pain show an altered response to swimming practice. The results of the current study have implications for training load and injury management. It should prompt investigation into how the tendon reacts under varying load conditions.

BackgroundA history of hamstring strain injury (HSI) has been indicated as a primary risk factor for a future injury. It is unknown whether a prior strain influences the architectural characteristics of the hamstring.ObjectiveTo determine if alterations occur to the architecture of the long head (BFlh) muscle in those with a history of strain injury to this muscle.DesignReliability and retrospective case-control study design.SettingClinical setting with recreationally active males and elite Australian Footballers.Participants31 males (Australian Footballers n=14, recreational males n=17). Of the 31 participants, 18 had a prior unilateral HSI, whereas the other 13 formed an uninjured control group.Risk factor assessmentThe independent variables were muscle fascicle length (FL), pennation angle (PA) and thickness (MT)).Main outcome measureThe BFlh muscle architecture of both limbs was assessed utilising B-mode ultrasound (General Electric Vivid-i) whilst rested in a prone position. The scan site was determined as 50% of the distance between the ischial tuberosity and the lateral knee joint line. The hypothesis prior to recruitment was that a history of injury would result in a reduction of FL and MT and an increase in PA. Reliability was assessed at a second time point within ten days of the initial visit and was determined utilising intra-class correlations (ICC).ResultsThe assessment of the architectural characteristics of the BFlh was shown as reliable whilst in a rested state (FL and PA ICC=0.97, MT=0.96). PA's (P=.001) and FL's (P=.013) were significantly less in the previously injured BFlh then the contralateral uninjured limb. Muscle thickness was not significantly different (p=0.466).ConclusionsUltrasound is a reliable measure of architectural characteristics in the BFlh. A previously injured BFlh displays reductions in FL and increases in PA. These variations may partly explain the high rate of recurrence of HSI's.

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