title: Biomechanical Considerations in the Competitive Swimmer's Shoulder.
abstract: BACKGROUND
  Competitive swimming has become an increasingly popular sport in the United States. In 2007, more than 250 000 competitive swimmers were registered with USA Swimming, the national governing body. The average competitive swimmer swims approximately 60 000 to 80 000 m per week. With a typical count of 8 to 10 strokes per 25-m lap, each shoulder performs 30 000 rotations each week. This places tremendous stress on the shoulder girdle musculature and glenohumeral joint, and it is why shoulder pain is the most frequent musculoskeletal complaint among competitive swimmers.
  
  
  METHODS
  Articles were obtained through a variety of medical search sources, including Medline, Google Scholar, and review articles from 1980 through January 2010.
  
  
  RESULTS
  The most common cause of shoulder pain in swimmers is supraspinatus tendinopathy. Glenohumeral instability and labral tears have also been reported, but a paucity of information remains regarding prevalence and treatment in swimmers.
  
  
  CONCLUSIONS
  Because of the great number of stroke repetitions and force generated through the upper extremity, the shoulder is uniquely vulnerable to injury in the competitive swimmer. Comprehensive evaluation should include the entire kinetic chain, including trunk strength and core stability.
authors.affiliation: Lifestrength Physical Therapy, Inc, Towson, Maryland.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Heinlein
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Cosgarea