title: The relationship between latissimus dorsi stiffness and altered scapular kinematics among asymptomatic collegiate swimmers.
abstract: OBJECTIVE
  To determine the strength of the relationship between latissimus dorsi stiffness and altered scapular kinematics among swimmers.
  
  
  METHODS
  Cross sectional.
  
  
  METHODS
  Laboratory.
  
  
  METHODS
  Nineteen NCAA Division III swimmers (7 male, 12 female) (age = 18.8 ± 0.9 years, height = 174.7 ± 8.9 cm, mass = 71.6 ± 11.9 kg) volunteered to participate. Subjects had no recent history of upper extremity pathology or any previous surgery.
  
  
  METHODS
  We measured latissimus dorsi stiffness of the dominant arm while in a lengthened position with a myotonometer. We used an electromagnetic tracking device with specialized software to measure scapular kinematics at humeral elevation angles of 30°, 60°, 90°, and 110° within the scapular plane.
  
  
  METHODS
  Latissimus dorsi stiffness and scapular upward/downward rotation, internal/external rotation, and anterior/posterior tilt.
  
  
  RESULTS
  Latissimus dorsi stiffness showed moderate-to-good relationships with increased scapular upward rotation (r > -0.63, P < 0.002) and posterior tilt (r > -0.62, P < 0.004) at all four angles of humeral elevation. Increased latissimus dorsi stiffness also showed moderate-to-good relationships with decreased scapular internal rotation at humeral elevation angles of 60° (r = 0.47, P = 0.03) and 90° (r = 0.54, P = 0.01).
  
  
  CONCLUSIONS
  Our results suggest there are several moderate-to-good relationships between increased latissimus dorsi stiffness in swimmers and altered scapular upward rotation, internal rotation, and posterior tilt at various angles of humeral elevation. If latissimus dorsi stiffness is not addressed subsequent scapular alterations, which have been associated with shoulder dysfunction, may occur.
authors: Illinois State University, School of Kinesiology and Recreation, Campus Box 5120, Normal, IL 61790, USA. klaudner@ilstu.edu
authors: Kevin G
authors: KG
authors: Laudner
authors: Jeffrey G
authors: JG
authors: Williams
mesh_terms: D000293:Adolescent; D001696:Biomechanical Phenomena; D003430:Cross-Sectional Studies; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D018763:Muscle Fatigue / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D012540:Scapula / Q000502:physiology*; D013550:Swimming / Q000502:physiology*