title: Evaluation of general joint laxity, shoulder laxity and mobility in competitive swimmers during growth and in normal controls.
abstract: The aim of the study was to evaluate differences between competitive swimmers and a reference group of school children concerning general joint laxity, laxity of the glenohumeral joint and range of motion in the shoulder. Materials and methods. Competitive swimmers (n = 120) were compared with references consisting of age and gender matched school children (n = 1277). General joint laxity was evaluated with the Beighton score. Anterior glenohumeral laxity was assessed according to the drawer test, and inferior glenohumeral laxity according to the sulcus test. Shoulder rotation was measured with a goniometer.
  
  
  RESULTS
  Male swimmers of both age groups showed a higher degree of general joint laxity compared with the reference group while 9-year-old female swimmers alone had a lower degree of general joint laxity compared with references. No significant difference concerning shoulder laxity was noticed between groups. There was a decreased internal rotation in male and female swimmers as compared with the reference group. External rotation was reduced in female swimmers as compared with the female references. The same result was observed in male swimmers, but only at the age of 12 years.
  Competitive swimming in children seems to lead to a decreased range of motion with regard to shoulder rotation. However, the reason for this is still unclear and further investigations are needed.
authors.affiliation: Department of Surgical Sciences, Section of Sports Medicine, Karolinska Institutet, Stockholm, Sweden. anna.jansson@kirurgi.ki.se
authors.forename: Anna
authors.initials: A
authors.lastname: Jansson
authors.forename: Tönu
authors.initials: T
authors.lastname: Saartok
authors.forename: Suzanne
authors.initials: S
authors.lastname: Werner
authors.forename: Per
authors.initials: P
authors.lastname: Renström
mesh_terms: D002648:Child; D005260:Female; D006801:Humans; D007593:Joint Instability; D008297:Male; D016059:Range of Motion, Articular / Q000502:physiology*; D012785:Shoulder Joint / Q000502:physiology*; D013548:Sweden; D013550:Swimming