Isometric strength of scapular retraction and protraction in competitive swimmers and healthy non-competitive females

he purposes of this study were to assess strength of the scapular musculature in a clinically practical and reliable manner and to determine the extent to which scapular muscles might contribute to shoulder and arm function. Twenty-five competitive swimmers (who swam at least 7,500 m/wk during training) and 25 healthy females (who were not competitively active) were tested on two occasions within a two week period. Isometric strength of the scapular retractor and protractor muscles of the preferred arm were determined using a hand-held dynamometer to measure resistance forces directly to the scapula, with the subject prone and the arm placed in three positions corresponding to the front crawl stroke in swimming: (1) hand entry, (2) mid or propulsive phase, and (3) end or hand exit phases. Reliability coefficients were used to determine reliability of three repetitions on one and two occasions, for each movement and position. Averaging of scores over two test occasions was required to yield acceptable reliability coefficients...