title: Assessment of subacromial space and its relationship with scapular upward rotation in college baseball players.
abstract: BACKGROUND
  Subacromial impingement is a common injury in baseball players and has been linked to a reduction in the subacromial space. In addition, it has been suggested that decreases in scapular upward rotation will lead to decreases in the subacromial space and ultimately impingement syndrome.
  
  
  OBJECTIVE
  The objective of this study was to evaluate the relationship between acromiohumeral distance and scapular upward rotation in healthy college baseball players.
  
  
  METHODS
  Posttest-only study design.
  
  
  METHODS
  Controlled laboratory setting.
  
  
  METHODS
  24 healthy college baseball players.
  
  
  METHODS
  Participants were measured for all dependent variables at preseason.
  
  
  METHODS
  Acromiohumeral distance at rest and 90° of abduction was measured with a diagnostic ultrasound unit. Scapular upward rotation at rest and 90° of abduction was measured with a digital inclinometer.
  
  
  RESULTS
  Dominant-arm acromiohumeral distance at rest and 90° of abduction (P = .694, P = .840) was not significantly different than in the nondominant arm. In addition, there was not a significant correlation between acromiohumeral distance and scapular upward rotation at rest and 90° of abduction for either the dominant or the nondominant arm.
  
  
  CONCLUSIONS
  These results indicate that the acromiohumeral distance is not adapting in the dominant arm in healthy throwing athletes. In addition, a relationship was not identified between acromiohumeral distance and scapular upward rotation, which was previously suggested. These results may suggest that changes that are typically seen in an injured population may be occurring due to the injury and are not preexisting. In addition, scapular upward rotation may not be the only contributing factor to acromiohumeral distance.
authors.affiliation: Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Stephen John
authors.initials: SJ
authors.lastname: Thomas
authors.forename: Charles Buz
authors.initials: CB
authors.lastname: Swanik
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Kaminski
authors.forename: Jill S
authors.initials: JS
authors.lastname: Higginson
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Swanik
authors.forename: Levon N
authors.initials: LN
authors.lastname: Nazarian
mesh_terms: D000293:Adolescent; D000328:Adult; D056352:Athletes; D001484:Baseball / Q000293:injuries*; D006801:Humans; D016059:Range of Motion, Articular; D017006:Rotator Cuff / Q000503:physiopathology*; D000070636:Rotator Cuff Injuries; D012540:Scapula / Q000293:injuries / Q000503:physiopathology*; D019534:Shoulder Impingement Syndrome / Q000000981:diagnostic imaging / Q000503:physiopathology*; D000070599:Shoulder Injuries; D012785:Shoulder Joint / Q000000981:diagnostic imaging / Q000503:physiopathology; D014463:Ultrasonography; D014495:Universities; D055815:Young Adult