Background: Improvement of the lumbo-pelvic stability can reduce the compensatory action of the erector spinae (ES) during prone hip extension (PHE). Furthermore, the application of abdominal drawing-in (ADI) maneuver increases the action of gluteus maximus (GM) and decreases the action of ES during PHE by improving the lumbo-pelvic stability. However, the post-ADI exercise effects on PHE, not the real-time application of ADI maneuver, has not been studied.
Objects: This study is aimed at investigating the post-ADI exercise effects on the muscle activities of GM and ES during PHE.
Methods: A total of 24 female adults participated in the study, and they were divided into two groups: Those with normal abdominal muscles (n1=12) and those with weak abdominal muscles (WA) (n2=12). Before the intervention, the subjects’ GM and ES muscle activities during PHE were measured. Subsequently, the two groups were asked to perform the ADI exercise for 10 minutes. After the ADI exercise, the GM and ES activities were equally measured during PHE.
Results: The comparison result of the ES muscle activities before intervention shows a significant difference between the two groups (p<.05); the WA group showed higher muscle activities than the normal group. For the within-group comparison, the muscle activities of the ES in the WA group significantly decreased after the ADI exercise (p<.05). For the GM muscle activity, no significant difference was observed in all comparisons (p>.05). For the changes in muscle activities before and after the ADI exercise, a significant difference exists between the two groups only for the changes in ES activities (p<.05); WA group exhibits higher changes than the normal group. By contrast, no significant difference exists between the two groups for the changes in GM activities (p>.05).
Conclusion: After the ADI exercise, the compensatory action of ES in the female adults with WC is implied to decrease during PHE.

Abstract
 Ⅰ. 서론
 Ⅱ. 연구방법
  1. 연구대상자
  2. 실험 기기 및 도구
  3. 실험절차
  4. 분석방법
 Ⅲ. 결과
 Ⅳ. 고찰
 Ⅴ. 결론
 References

• 김동우(대구대학교 대학원 물리치료학과) | Dong-woo Kim (Dept. of Physical Therapy, The Graduate School, Daegu University)
• 박한규(대구대학교 대학원 물리치료학과) | Han-kyu Park (Dept. of Physical Therapy, The Graduate School, Daegu University) Corresponding author