Background The shoulder is the most commonly injured joint among competitive swimmers, and there are suggestions that sex, swimming stroke and level or training/competition are risk factors, but previous studies are inconclusive and have used small cohorts and/or relatively low level competitors.

Objectiv To document the incidence, nature, severity and location of shoulder injuries in competitive highly trained swimmers, and whether these factors were influenced by sex, swimming stroke and level of competition.

Design Retrospective study.

Setting Swimming competitions and clubs.

Participants 132 young competitive adult swimmers (61 females, 71 males; age, 21±2 yrs; body mass: 73±11kg; current training volume, 16±4 hrs/wk; competitive history 9±3 years).

Risk factor assessment Participants completed a retrospective questionnaire concerning their age, sex, competitive standard, primary stroke, recent training volume.

Main outcome measurements They also recorded their experience of shoulder injury incidence (new injury, recurrence), time loss severity (mild, moderate, severe), nature of injury onset (acute/chronic) and location (left, right, both).

Results 99 swimmers (74%) had experienced shoulder injury, collectively reporting 124 unique injuries, and >50% of these injuries had recurred at least once. 22% of swimmers were currently experiencing shoulder pain, and 10% were currently receiving treatment for shoulder injury. Injury incidence was not influenced by sex (P=.223) or competitive standard (P=.415). There were more chronic than acute injuries (86 vs 38; P=.001). There were tendencies for more injuries to the right than left shoulder (65 vs 43, P=.066), and for a higher incidence of severe injuries than expected (P=.053). Shoulder injury was 50% lower for breaststroke swimmers, but this difference was not significant P=.245).

Conclusions Injury incidence was not influenced by sex or level of competition, but was 50% lower for breaststroke swimmers. Despite the symmetrical nature of swimming the right shoulder seems to be at greater risk of injury.