Affiliations: [a] Operation and Support Team, CJ Corporation, Seoul, South Korea | [b] Department of Physical Therapy, College of Health and Medical Science, Cheongju University, Cheongju, South Korea
Correspondence:
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Corresponding author: Duck-Won Oh, Department of Physical Therapy, College of Health and Medical Science, Cheongju University, 298 Daeseong-ro, Cheongwon-gu, Cheongju, Chungcheongbuk-do, 28503, Korea. Tel.: +82 43 229 8679; E-mail: [email protected].
Abstract: BACKGROUND: Side-lying hip abduction exercise could be beneficial to improve the neuromuscular control of the hip abductor; however, there has been limited information available to determine the exercise load during the exercise. OBJECTIVE: This study aimed to demonstrate the effects of using external loads on the hip abductor muscles during side-lying hip abduction exercises in females with gluteus medius (GM) weakness. METHODS: This study enrolled 24 females with weakness in the GM. Electromyographic (EMG) data of the quadratus lumborum (QL) and GM muscles were recorded during the exercise under three load conditions: no-load, external load-1 (3% of body weight), and external load-2 (5% of body weight). RESULTS: During the exercise, the EMG activities of the QL were significantly different under all three conditions (p< 0.05), with greater activity observed in the external load-2 condition (92.05 ± 65.93% maximal voluntary isometric contraction [MVIC]) as compared to the others, and in the external load-1 condition (82.47 ± 57.36% MVIC) as compared to the no-load condition (48.94 ± 45.09% MVIC). Furthermore, the GM/QL ratios showed significant differences between no-load (1.78 ± 1.47) and external load-1 conditions (0.93 ± 0.60), and between no-load and external load-2 (0.85 ± 0.45) conditions (p< 0.05). CONCLUSION: These findings suggest that greater load could be a factor to increase the QL activity during the exercise in females with weakened GM.
