title: The most effective exercise for strengthening the supraspinatus muscle: evaluation by magnetic resonance imaging.
abstract: BACKGROUND
  Electromyography has been used to determine the best exercise for strengthening the supraspinatus muscle, but conflicting results have been reported. Magnetic resonance imaging T2 relaxation time appears to be more accurate in determining muscle activation.
  
  
  OBJECTIVE
  To determine the best exercises for strengthening the supraspinatus muscle.
  
  
  METHODS
  Criterion standard.
  
  
  METHODS
  Six male volunteers performed three exercises: the empty can, the full can, and horizontal abduction. Immediately before and after each exercise, magnetic resonance imaging examinations were performed and changes in relaxation time for the subscapularis, supraspinatus, infraspinatus, teres minor, and deltoid muscles were recorded.
  
  
  RESULTS
  The supraspinatus muscle had the greatest change among the studied muscles in relaxation time for the empty can (10.5 ms) and full can (10.5 ms) exercises. After the horizontal abduction exercise the change in relaxation time for the supraspinatus muscle (3.6 ms) was significantly smaller than that for the posterior deltoid muscle (11.5 ms) and not significantly different from that of the other muscles studied.
  
  
  CONCLUSIONS
  The empty can and full can exercises were most effective in activating the supraspinatus muscle.
authors.affiliation: Department of Orthopaedic Surgery, Tokushima Red Cross Hospital, 28-1 Shinbiraki, Chuden-cho, Komatsushima City, Tokushima 773-8502, Japan.
authors.forename: Yoshitsugu
authors.initials: Y
authors.lastname: Takeda
authors.forename: Shinji
authors.initials: S
authors.lastname: Kashiwaguchi
authors.forename: Kenji
authors.initials: K
authors.lastname: Endo
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Matsuura
authors.forename: Takahiro
authors.initials: T
authors.lastname: Sasa
mesh_terms: D000328:Adult; D005081:Exercise Therapy / Q000379:methods*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009126:Muscle Relaxation / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D012016:Reference Values; D017006:Rotator Cuff / Q000502:physiology; D012782:Shoulder / Q000502:physiology*; D014891:Weight Lifting / Q000502:physiology