The aim of this study was to determine whether side-lying hip abduction exercise while applying manual pelvic fixation is more effective than hip abduction without manual pelvic fixation for promoting deep trunk muscle activity.
This is a cross-sectional study comparing deep trunk muscle activation between hip abduction exercise without and with manual pelvic fixation in ten participants. Muscle activation was measured using fine-wire and surface electromyography.
Hip abduction with manual pelvic fixation was found to result in significantly more recruitment of all studied deep trunk muscles except the ipsilateral obliquus externus compared with hip abduction without manual pelvic fixation (P < 0.05). The greatest increased activation was seen in the ipsilateral deep and superficial multifidus. The increase in deep multifidus percentage of maximal voluntary contraction was greater than that of the rectus abdominis, the obliquus externus, the transversuus abdominis/obliquus internus, the lumbar erector spinae, the superficial multifidus, and the gluteus medius (P < 0.05). The superficial multifidus percentage of maximal voluntary contraction was significantly increased over that of the rectus abdominis and the obliquus externus (P < 0.05). Moderate correlation between deep and superficial multifidus activation was found (Pearson correlation coefficient, 0.537).
Hip abduction training in the side-lying position while applying manual pelvic fixation seems to be more effective for recruiting deep trunk muscles for dynamic lumbar spinal stabilization.
From the Department of Physical Medicine and Rehabilitation, College of Medicine, Yeungnam University, Daegu, Republic of Korea (EHK, SHJ, YWC, KJK, SHA); Department of Biomedical Engineering, The University of Iowa, Iowa City, Iowa (THL); Department of Physical Therapy, Youngsan University, Yangsan, Gyeongsangnam-do, Republic of Korea (SHP); Daegu Research Center for Medical Device and Rehab. Engineering, Korea Institute of Machinery & Materials (CSK); and Medical Devices Clinical Trial Center (HSC, SHA) and Biomedical Engineering Institute (SHA), Yeungnam University, Daegu, Republic of Korea.
All correspondence and requests for reprints should be addressed to: Sang Ho Ahn, MD, PhD, Department of Rehabilitation Medicine & Spine Center, College of Medicine, Yeungnam University, 317-1, Daemyung-Dong, Nam-Gu, Daegu, 705-717, Republic of Korea.
Supported by the 2008 Yeungnam University Research Grant. This study was supported by a grant of the Korea Healthcare technology R&D Project, Ministry for Health, Welfare & Family Affairs, Republic of Korea (A084177).
Financial disclosure statements have been obtained, and no conflicts of interest have been reported by the authors or by any individuals in control of the content of this article.