More on incidence of impingement and tendinopathy among swimmers

It has been estimated that 50-67% of national or world class swimmers have had significant shoulder problems (chronic injuries). They appear most frequently among sprinters, rather than distance swimmers.

There is a high incidence of impingement problems among freestylers, butterflyers, and backstroke swimmers.

From the journal Medicine and science in sports and exercise published by Lippincott Williams & Wilkins,
The shoulder movements exhibited during performance of the front-crawl stroke were measured using three-dimensional videography, and the instances at which each shoulder was experiencing impingement were identified. Results: On average, impingement occurred 24.8% of the stroke time.

Swimmers at high risk of experiencing shoulder impingement had three characteristics in their stroking techniques: (a) a large amount of internal rotation of the arm during the pull phase. (b) a late initiation of external rotation of the arm during the recovery phase, and (c) a small amount of tilt angle. In such cases a high incidence of shoulder impingement was observed for the shoulder on the ipsilateral side

Check out http://www.scsepf.org/doc/020108/Paper5.pdf


From the American Orthopaedic Society for Sports Medicine 2005 Annual Meeting:
Supraspinatus tendinosis is seen in 67% of elite swimmers tested. A study of 52 elite swimmers suggested there is a strong relationship between swimming time and distance and the incidence of supraspinatus tendinosis, a frequent cause of shoulder pain in swimmers.

The swimmers (28 male and 24 female) ranged in age from 13 to 25 years. More than half of the athletes had supraspinatus tendinosis, according to the test results. Researchers found that the amount of time and distance the athletes swam weekly influenced the development of supraspinatus tendinosis. Swimmers who trained more than 15 hours weekly were twice more likely to have tendinopathy than those who trained less.

Those who swam more than 35 km weekly were four times more likely to have the condition.

Tendinopathy has an increased incidence with age and the male gender and with obesity.


References:
http://www.orthosupersite.com/view.asp?rid=3734
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2505234
http://cat.inist.fr/?aModele=afficheN&cpsidt=1274741