200 - 400 m breaststroke event dominate among knee overuse injuries in elite swimming athletes

We hypothesized that pool swimming has a low risk for acute injuries; however overuse injuries are predominant, depending on exposure time and swimming discipline.341 elite swimmers (19 +/- 11 years, BMI 20.3 +/- 3) were enrolled. Swimming was performed at mean since 10.1 +/- 8 years with 3.8 units every week during 43 weeks every year.The overall pool swimming injury rate was 0.39 / 1000 h. Overuse injuries (0.22 / 1000 h) were more frequent than acute injuries (0.17 / 1000 h). The upper extremity was involved more frequently (0.11 / 1000 h) than the trunk (0.067 / 1000 h) or the lower extremity (0.085 / 1000 h). Knee pain was predominant (0.17 / 1000 h) followed by shoulder overuse injuries (0.11 / 1000 h). Especially the 200 - 400 m breaststroke event had a fivefold higher risk for knee pain (relative risk, RR 5.1, p = 0.001). Freestyle had a reduced relative risk for knee pain (RR 0.5, p = 0.03), where shoulder overuse syndromes were predominant. Butterfly increased acute shoulder injury with RR 4.4 (p = 0.004), cervical spine injuries (RR 4.0, p = 0.03) and lower back pain (RR 2.5, p = 0.011). Swimming for more than four times a week had a higher risk for knee injuries (RR 2.1) and shoulder injuries (RR 4.0). We found that stretching was associated with a fivefold reduced risk for overuse knee injuries.Competitive swimming is a reasonable safe sport, where overuse injuries are predominant. 200 - 400 m breaststroke events increase the risk for knee overuse injuries more than other disciplines. Training for more than four times a week increases the risk twofold for knee and fourfold for shoulder overuse injuries.