title: Is subscapularis recruited in a similar manner during shoulder internal rotation exercises and belly press and lift off tests?
abstract: OBJECTIVE
  Although the belly press and lift off tests are recommended to assess subscapularis function, shoulder internal rotation (IR) exercises performed in other shoulder positions are more commonly used to restore subscapularis function. It is not known if shoulder IR exercises specifically activate subscapularis to the same degree as the lift off and belly press tests, and thus have the potential to effect subscapularis strength gains. Therefore, the aim was to compare subscapularis activation levels with those of other shoulder internal rotator muscles during the belly press and lift off tests and shoulder IR exercise positions.
  
  
  METHODS
  Original research.
  
  
  METHODS
  Twenty asymptomatic volunteers performed maximal isometric contractions during the belly press and lift off tests and shoulder IR performed at 90° and 0° abduction in an upright position and supported at 90° abduction in supine. Muscle activation levels were recorded using a combination of indwelling and surface electrodes. Data were normalized to maximum voluntary contractions and averaged.
  
  
  RESULTS
  Moderate average subscapularis activation levels were recorded during all shoulder IR tasks examined with no significant difference between tasks (p=0.18). The belly press test was the only IR task in which subscapularis activation levels were significantly higher than all other shoulder internal rotator muscles (p<0.05).
  
  
  CONCLUSIONS
  Shoulder IR exercises activate subscapularis to similar moderate levels as the belly press and lift off tests and therefore, have similar potential to strengthen subscapularis. However, the belly press test, with significantly higher subscapularis activation than other shoulder internal rotators, more specifically targets subscapularis.
authors.affiliation: Sydney Medical School, University of Sydney, Australia.
authors.forename: Karen A
authors.initials: KA
authors.lastname: Ginn
authors.affiliation: Sydney Medical School, University of Sydney, Australia. Electronic address: darren.reed@sydney.edu.au.
authors.forename: Darren
authors.initials: D
authors.lastname: Reed
authors.affiliation: Sydney Medical School, University of Sydney, Australia.
authors.forename: Chelsea
authors.initials: C
authors.lastname: Jones
authors.affiliation: Sydney Medical School, University of Sydney, Australia.
authors.forename: Anthony
authors.initials: A
authors.lastname: Downes
authors.affiliation: Sydney Medical School, University of Sydney, Australia; Australian Catholic University, Australia.
authors.forename: Ian
authors.initials: I
authors.lastname: Cathers
authors.affiliation: Faculty of Health Sciences, University of Sydney, Australia.
authors.forename: Mark
authors.initials: M
authors.lastname: Halaki
mesh_terms: D000328:Adult; D004576:Electromyography; D015444:Exercise / Q000502:physiology*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D008297:Male; D011187:Posture; D012399:Rotation; D017006:Rotator Cuff / Q000502:physiology*; D012782:Shoulder / Q000502:physiology*
keywords: Electromyography; Exercise; Rehabilitation; Strengthening; Subscapularis manual muscle test