title: Stretching and strengthening exercises: their effect on three-dimensional scapular kinematics.
abstract: OBJECTIVE
  To quantitatively evaluate the effects of commonly used shoulder exercises on shoulder kinematics and resting posture.
  
  
  METHODS
  A repeated-measures design was used with measurements performed before and after a 6-week exercise program.
  
  
  METHODS
  Twenty asymptomatic subjects with forward shoulder posture were recruited. Stretching exercises for the pectoral muscles and resisted strengthening exercises for the scapular retractors and elevators and the glenohumeral abductors and external rotators were performed three times per week for 6 weeks. A three-dimensional electromechanical digitizer was used to measure thoracic inclination and scapular orientation and position. These measurements were taken with the arm (1) at the side, (2) abducted to 90 degrees, and (3) at maximal abduction. The isometric force of glenohumeral external and internal rotation and horizontal abduction and adduction were measured with a hand-held dynamometer. All subjects were tested before and after the 6-week exercise program. Hotelling's T2 and paired t tests were used for data analysis.
  
  
  RESULTS
  The strength of horizontal abduction and internal and external rotation increased after exercise (p < .01). The anterior inclination of the thoracic spine decreased, and the glenohumeral contribution to arm elevation increased (p < .01). Resting scapular posture did not change. As the arm was abducted to 90 degrees, the scapula showed less upward rotation and less superior translation after the exercise program (p < .01).
  
  
  CONCLUSIONS
  The exercise program improved muscle strength, produced a more erect upper trunk posture, increased scapular stability, and altered scapulohumeral rhythm.
authors.affiliation: Department of Physical Therapy, Allegheny University of the Health Sciences, Philadelphia, PA, USA.
authors.forename: C H
authors.initials: CH
authors.lastname: Wang
authors.forename: P
authors.initials: P
authors.lastname: McClure
authors.forename: N E
authors.initials: NE
authors.lastname: Pratt
authors.forename: R
authors.initials: R
authors.lastname: Nobilini
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001696:Biomechanical Phenomena; D005081:Exercise Therapy / Q000379:methods* / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007537:Isometric Contraction; D008297:Male; D010369:Pectoralis Muscles / Q000503:physiopathology; D015203:Reproducibility of Results; D012540:Scapula / Q000503:physiopathology*; D012782:Shoulder