- 著者
- 
             
             Daisuke Uga
             
             Yasuhiro Endo
             
             Rie Nakazawa
             
             Masaaki Sakamoto
             
          
- 出版者
- 理学療法科学学会
- 雑誌
- Journal of Physical Therapy Science (ISSN:09155287)
- 巻号頁・発行日
- vol.28, no.1, pp.154-158, 2016 (Released:2016-01-30)
- 参考文献数
- 19
- 被引用文献数
- 
             
             2
             
             
             8
             
             
          
        
        [Purpose] This study aimed to clarify activation of the infraspinatus and scapular          stabilizing muscles during shoulder external rotation at various shoulder elevation          angles. [Subjects] Twenty subjects participated in this study and all measurements were          performed on the right shoulder. [Methods] Isometric shoulder external rotation strength          and surface electromyographic data were measured with the shoulder at 0°, 45°, 90°, and          135° elevation in the scapular plane. The electromyographic data were collected from the          infraspinatus, upper trapezius, middle trapezius, lower trapezius, and serratus anterior          muscles. These measurements were compared across the various shoulder elevation angles.          [Results] The strength measurements did not differ significantly by angulation. The          infraspinatus activity was 92%, 75%, 68%, and 57% of the maximum voluntary contraction,          which significantly decreased as shoulder elevation increased. The serratus anterior          activity was 24%, 48%, 53%, and 62% of the maximum voluntary contraction, which          significantly increased as shoulder elevation increased. [Conclusion] Shoulder external          rotation torque was maintained regardless of shoulder elevation angle. The shoulder          approximated to the zero position as the shoulder elevation increased so that          infraspinatus activity decreased and the scapular posterior tilting by the serratus          anterior might generate shoulder external rotation torque.