Swimmer's Knee Injuries
Ross Hauser, M.D., Marion Hauser, M.S.,R.D.

A study on the incidence of injuries to various parts of the musculoskeletal system of swimmers, and noticed that a high percentage of breaststroke swimmers complained of pain in the medial knee(1).
 

This condition has been termed "breaststroker's knee", although further studies on a population of 391 competitive swimmers showed that breaststroker's knee was diagnosed in 56 out of 77 breaststroke swimmers (73 percent), but also in 153 out of 314 swimmers (48 percent) who used either the freestyle, backstroke, or butterfly stroke(2).
 

The condition is primarily seen in breaststrokers because of the whip kick where much of the speed in the breaststroke comes from. Initially researchers reported that the condition was caused by weakness in the medial collateral ligament, resulting from repeated stretching during breaststroke swimming.(1)
 

The medial collateral ligament is the main supporting structure on the medial side of the knee; it is also called the tibial collateral ligament. Tension in the ligament increases as the knee moves from flexion to extension. This is exactly what happens during the kicking motion of the whip kick during breaststroke swimming. All the force is generated right at, directly on the medial collateral ligament.
 

Different authors point to different areas on the ligament that are causing the pain, but the main point is that, uniformly the pain-producing structure in breaststroker's knee is a laxity or sprain of the medial collateral ligament. (3).
 

The cause of breaststroker's knee, according to traditional orthopedic sports medicine, is due to improper technique of doing the whip kick.(4) For this reason, biomechanical factors are adjusted and the athlete is told to take time off from the sport. Some authors have suggested breaststrokers take at least two months off per year to allow the medial collateral ligament to heal.(1)
 

Most competitive athletes we have met do not care to take two months off from their sports. The swimmer with breaststroker's knee comes in complaining of medial knee pain, especially while swimming. There is severe pain upon palpation of both attachments of the medial collateral ligament. This then meets all the criteria for the athlete to receive Prolotherapy and makes him/her an excellent Prolotherapy candidate. The Prolotherapy criteria are these: desire to get better, willingness to get shots, pain emanating from a ligament or tendon, and the pain can be reproduced in the office. Athletes with breaststroker's knee meet all of these criteria and the condition responds beautifully to Prolotherapy.
 

After a swimmer receives Prolotherapy to the injured ligament, the physician urges them to train harder, not rest. Prolotherapy can make that ligament tremendously strong so the athlete never has to think about injuring it. Three to six sessions of Prolotherapy are generally required to resolve breaststroker's knee.

1. Kennedy, J. Hawkins, R. Breaststroker's Knee. Physician and Sportsmedicine. 1974;2:33-38.
2. Vizsoly, P. Breaststroker's knee. An analysis of epidemiological and biomechanical factors. American Journal of Sports Medicine. 1987; 15:63-71.
3. Stulberg, S. Breaststroker's knee: pathology, etiology, and treatment. American Journal of Sports Medicine. 1980; 8:164-171.-Costill, D. Handbook of Sports Medicine and Science Swimming. Oxford: Blackwell Scientific Publications, 1992.
4. Vizsoly, P. Breaststroker's knee. An analysis of epidemiological and biomechanical factors. American Journal of Sports Medicine. 1987; 15:63-71.-Johnson, J. Musculoskeletal injuries in competitive swimmers. Mayo Clinic Proceedings. 1987; 62:289-304.