A Comparison of the Shoulder Stabilizer Muscle Activities During Push-up Plus Between Persons With and Without Winging Scapular

푸시업플러스(Push-up plus) 운동 시 견갑골 익상 유무에 따른 어깨안정근의 근활성도 비교

  • Park, Jun-Sang (Dept. of Safety & Health, Labor Relations, Korea Delphi Automotive Systems Corporation) ;
  • Jeon, Hye-Seon (Dept. of Physical Therapy, College of Health Science, Yonsei University, Dept. of Ergonomic Therapy, The Graduate School of Health and Environment, Yonsei University, Institute of Health Science, Yonsei University) ;
  • Kwon, Oh-Yun (Dept. of Physical Therapy, College of Health Science, Yonsei University, Dept. of Ergonomic Therapy, The Graduate School of Health and Environment, Yonsei University, Institute of Health Science, Yonsei University)
  • 박준상 (한국델파이주식회사 노경협력팀 안전과) ;
  • 전혜선 (연세대학교 보건과학대학 물리치료학과, 보건환경대학원 인간공학치료학과, 보건과학연구소) ;
  • 권오윤 (연세대학교 보건과학대학 물리치료학과, 보건환경대학원 인간공학치료학과, 보건과학연구소)
  • Received : 2007.03.15
  • Accepted : 2007.04.11
  • Published : 2007.05.21

Abstract

This study was carried out to compare the muscle activities of the shoulder stabilizers between persons with and without winging scapular during push-up plus exercise (adds the scapular protraction to the general push-up exercise). For this study, eleven males with winging scapular and eleven healthy males were recruited. Surface electromyographic (EMG) activity was recorded from the serratus anterior, upper trapezius, lower trapezius, infraspinatus, and pectoralis major while the subjects performed the push-up plus. Each push-up plus was subdivided into three phases according to the elbow position which was measured using the 3-D motion analysis system: elbow flexion (EF), elbow extension (EE), and shoulder protraction phases (SP). Two-way repeated measure ANOVA (phase ${\times}$ group) were used for statistical analysis. There was significant phase by group interaction only on the EMG composition ratio of the serratus anterior (p>.05). The EMG composition ratio of the serratus anterior was significantly higher in SP than in either EF or EE however, it was not different between winging scapular and normal groups. For both groups, the EMG composition ratio of upper trapezius, lower trapezius, and pectoralis major was significantly different across the phases of push-up plus, but the infraspinatus EMG composition ratio was not. For both groups, in EF and EE phases, the EMG composition ratio of both pectoralis major and serratus anterior were relatively higher than that of other muscles. However, in both groups, the EMG composition ratio of the serratus anterior became much more predominant than that of the pectoralis major. In addition, infraspinatus activated greater than pectoralis major. These results showed that the push-up plus exercise is effective to selectively strengthen the serratus anterior for both individuals with and without winging scapular, but not equally effective for other shoulder stabilizers.

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