Background: Scapular winging is a prominence of the entire scapular medial border, mainly caused by insufficient activity of the serratus anterior (SA) and imbalance of scapulothoracic muscles. Push-up plus (PUP) exercise has been commonly used to increase SA muscle activity. The facilitation of abdominal muscle may affect scapular muscle activity by myofascial connections. Thus, the sequential activation of the turnk muscles is suggested to facilitate the transition of proper force from upper limb and restore force couple of scapular muscles. The abdominal drawing-in maneuver (ADIM) has been effective in improving activation of the deep trunk muscles during movement. Objects: The aim of this study was to determine the effect of ADIM on the activity of the upper trapezius (UT), lower trapezius (LT), and SA during PUP exercises in subjects with scapular winging. Methods: Fourteen men with scapular winging (determined as a of distance between the scapular medial border and thoracic wall over 3 ㎝) volunteered for our study. The subjects performed the PUP exercise with and without ADIM. Surface electromyography was used to collect the electromyography data of the UT, LT, and SA. A scapulometer was used to measure the amount of scapular winging. Results: SA activity was significantly greater and scapular winging significantly lower during the PUP exercise with ADIM than during those without ADIM. Conclusion: PUP exercise with ADIM can be used as an beneficial method to improve SA activation and to reduce the amount of scapular winging in subjects with scapular winging.

7. Kim DE. Phys Ther Korea. 2017(1)61-70
 Abstract
 Introduction
 Methods
  Subjects
  EMG recording and data processing
  Scapular winging measurement
  Procedures
  Preferred push-up plus exercise
  Push-up plus exercise with abdominaldrawing-in maneuver
  Statistical Analysis
 Results
  Muscle activity and muscle activity ratios
  Scapular winging
 Discussion
 Conclusion
 References

• Da-eun Kim(Dept. of Physical Therapy, The Graduate School, Yonsei University)
• A-reum Shin(Dept. of Physical Therapy, The Graduate School, Yonsei University)
• Ji-hyun Lee(Dept. of Physical Therapy, The Graduate School, Yonsei University)
• Heon-seock Cynn(Dept. of Physical Therapy, College of Health Science, Yonsei University, Dept. of Ergonomic Therapy, The Graduate School of Health and Environment, Yonsei University) Corresponding author