title: Reliability of scapular classification in examination of professional baseball players.
abstract: BACKGROUND
  Clinically evaluating the scapulothoracic joint is challenging. To identify scapular dyskinesis, clinicians typically observe scapular motion and congruence during self-directed upper extremity movements. However, it is unclear whether this method is reliable.
  
  
  OBJECTIVE
  We therefore determined the interrater reliability of a scapular classification system in the examination of professional baseball players.
  
  
  METHODS
  Seventy-one healthy uninjured professional baseball players between the ages of 18 and 32 years volunteered to participate. We used a digital video camera to film five repetitions of scapular plane elevation while holding a 2-pound weight. Four examiners then independently classified the motions on video into one of four types. Interrater reliability analysis using the kappa (k) statistic was performed for: (1) classifying each scapula into one of the four types; (2) classifying each scapula as being abnormal (Types I-III) or normal (Type IV); and (3) classifying both scapula as both being symmetric (both normal or both abnormal) or asymmetric (one normal, one abnormal).
  
  
  RESULTS
  We found low reliability for all analyses. In classifying each scapula as one of the four types, reliability was k = 0.245 for the left limb and k = 0.186 for the right limb. When considering the dichotomous classifications (abnormal versus normal), reliability was k = 0.264 for left and k = 0.157 for right. For bilateral symmetry/asymmetric, reliability was k = 0.084.
  
  
  CONCLUSIONS
  We found low reliability of visual observation and classification of scapular movement.
  
  
  CONCLUSIONS
  Current evaluation strategies for evaluating subtle scapular abnormalities are limited.
  
  
  METHODS
  Level III, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.
authors.affiliation: Physiotherapy Associates Scottsdale Sports Clinic, 9917 N 95th Street, Scottsdale, AZ 85258, USA. ellenbeckerpt@cox.net
authors.forename: Todd S
authors.initials: TS
authors.lastname: Ellenbecker
authors.forename: W Ben
authors.initials: WB
authors.lastname: Kibler
authors.forename: David S
authors.initials: DS
authors.lastname: Bailie
authors.forename: Roger
authors.initials: R
authors.lastname: Caplinger
authors.forename: George J
authors.initials: GJ
authors.lastname: Davies
authors.forename: Bryan L
authors.initials: BL
authors.lastname: Riemann
mesh_terms: D000328:Adult; D001484:Baseball / Q000502:physiology*; D006801:Humans; D008875:Middle Aged; D009068:Movement; D015588:Observer Variation; D010808:Physical Examination; D012540:Scapula / Q000502:physiology*; D012785:Shoulder Joint / Q000502:physiology*; D055815:Young Adult