title: Patterns of glenohumeral joint laxity and stiffness in healthy men and women.
abstract: OBJECTIVE
  The purpose of this study was to identify gender-related differences in glenohumeral (GH) joint laxity, stiffness, and generalized joint hypermobility in healthy men and women.
  
  
  METHODS
  Fifty-one healthy men and women were tested for generalized joint hypermobility, and anterior-posterior (AP) joint laxity and stiffness using a single-group factorial design.
  
  
  RESULTS
  Women exhibited significantly more anterior joint laxity (men 8.3 +/- 2.2 mm vs women 11.4 +/- 2.8 mm, P < 0.001) and less anterior joint stiffness (men 20.5 +/- 5.0 N x mm(-1) vs women 16.3 +/- 4.2 N x mm(-1), P < 0.01) than men. Men had significantly more posterior joint laxity than anterior (Ant 8.3 +/- 2.2 mm vs Post 9.6 +/- 2.9 mm; P < 0.001), and women also had significantly less anterior joint stiffness than posterior [Ant 16.3 +/- 4.2 N x mm(-1) vs Post 22.1 +/- 6.9 N x mm(-1); P < 0.01], Women also demonstrated significantly more generalized joint hypermobility than men (men 1.0 +/- 1.7 vs women 2.9 +/- 2.1; P = 0.02).
  
  
  CONCLUSIONS
  Our findings may indicate a possible increased risk for instability in women, especially those participating in sports that require repetitive overhead-throwing motion. Future investigations should seek to determine the contribution of increased GH joint laxity and decreased joint stiffness to various injury states and examine these variables in other populations such as overhead-throwing athletes.
authors.affiliation: Shoulder Kinematics Laboratory, University of Michigan, Ann Arbor 48109-2214, USA. Borsap@umich.edu
authors.forename: P A
authors.initials: PA
authors.lastname: Borsa
authors.forename: E L
authors.initials: EL
authors.lastname: Sauers
authors.forename: D E
authors.initials: DE
authors.lastname: Herling
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007593:Joint Instability; D008297:Male; D016059:Range of Motion, Articular; D012737:Sex Factors; D000070599:Shoulder Injuries; D012785:Shoulder Joint / Q000503:physiopathology*