Frequency, associated factors, and treatment of breaststroker's knee in competitive swimmers.

Thirty-six competitive breaststroke swimmers were interviewed and examined for knee pain specifically related to the breaststroke kick. Eighty-six percent of the subjects had a history of at least one episode of breaststroke knee pain, while 47.2% had breaststroke knee pain that occurred at least once a week. There was a significant relationship between more frequent knee pain and increasing swimmer's age, increasing years of competitive swimming, increasing breaststroke training distance, and decreasing warm-up distance. The subjects with frequent knee pain were found to have less internal rotation at the hip joint. The most common site of breaststroke knee pain was the medial portion of the knee, with specific sites differing among the individuals. The medial synovial plica syndrome may be a cause of breaststroke knee pain, since 47% of subjects with weekly knee pain had tender, thickened medial plicae. Palpation of those plicae produced pain similar to that experienced with the breaststroke kick. The findings in this study suggest that reducing or eliminating breaststroke training distance should be an initial measure in treatment. Applications of ice, changes in kick technique, stretching exercises to increase hip rotation, and administration of aspirin may also be effective. The breaststroke training distance should be increased very gradually in the early season, and warm-up distance should be adequate to help prevent the symptoms of breaststroker's knee.