title: Comparison of changes in supraspinatus muscle thickness in persons with subacromial impingement syndrome and asymptomatic adults.
abstract: OBJECTIVE
  To compare changes in supraspinatus muscle thickness in persons with subacromial impingement syndrome (SAIS) and asymptomatic adults and to determine the reliability of the ultrasound imaging (USI) protocol.
  
  
  METHODS
  Twenty-two persons with SAIS and 22 age- and gender-matched asymptomatic controls.
  
  
  METHODS
  Ultrasound images of supraspinatus muscle thickness at rest and at 0°, 30°, 60°, and 90° of arm elevation were captured and measured. To determine same-day intratester reliability, one examiner imaged the same subject twice and two examiners took turns capturing images in order to determine same-day intertester reliability. SUBJECTS were asked to return for between-day intratester reliability.
  
  
  RESULTS
  Statistical analyses revealed a larger mean supraspinatus thickness in the SAIS group at the 0° condition than in the asymptomatic group (p < 0.05). Same-day intratester and intertester reliability was good with ICC(2,3) = 0.73-0.96 for asymptomatic controls and ICC(2,3) = 0.61-0.94 for persons with SAIS. Overall, between-day intratester reliability was fair to good for most conditions [ICC(2,3) = 0.31-0.90].
  
  
  CONCLUSIONS
  The thicker supraspinatus muscles at 0° in the SAIS group may indicate a protective spasm. The USI protocol used in the study demonstrated good same-day intratester and intertester reliability for both groups.
authors.affiliation: Texas Health Resources Presbyterian Hospital , Dallas, TX , USA and.
authors.forename: Christiana
authors.initials: C
authors.lastname: Blume
authors.forename: Sharon S
authors.initials: SS
authors.lastname: Wang
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging* / Q000503:physiopathology; D015588:Observer Variation; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012782:Shoulder / Q000000981:diagnostic imaging* / Q000503:physiopathology; D019534:Shoulder Impingement Syndrome / Q000000981:diagnostic imaging* / Q000503:physiopathology; D014463:Ultrasonography
keywords: Imaging; rotator cuff; shoulder