Stimulation of Gluteal Muscles with Electro-Magnetic Stimulation: an Ultrasonographic Study.

, Seo, Han Gil; , Shin, Hyung Ik; , Lee, Joon Woo; , Lee, Sang Yoon

Original Article

Journal of the Korean Academy of Rehabilitation Medicine 2008;32(4):417-423.

Seo, Han Gil , Shin, Hyung Ik , Lee, Joon Woo , Lee, Sang Yoon

¹Department of Rehabilitation Medicine, Seoul National University College of Medicine, Korea. hyungik1@snu.ac.kr
²Department of Radiology, Seoul National University College of Medicine, Korea.

전자기자극을 이용한 둔부근의 자극: 초음파 연구

서한길, 신형익, 이준우¹, 이상윤

서울대학교 의과대학 재활의학교실, ¹영상의학교실

Abstract

Objective
To know if electro-magnetic stimulation can induce the contraction of gluteus medius and minimus muscles, and to compare pain induced by electro-magnetic stimulation of the gluteal muscles with that induced by transcutaneous neuromuscular electrical stimulation (NMES).
Method
Two different intensity of transcutaneous NMES (40 mA, 60 mA) and electro-magnetic stimulation (60%, 100%) were applied to the left buttock of 15 healthy male volunteers in random order. The ultrasound images of gluteal muscles and visual analog scale (VAS) of pain were obtained three times at each type of stimulation. The grade of muscle contraction and the VAS score of each type of stimulation were compared.
Results
At maximal stimulation intensity of our equipments, the mean VAS score was lower (p=0.012) in electro-magnetic stimulation than in transcutaneous NMES, and the grade of gluteus minimus contraction was higher (p=0.035) in electro-magnetic stimulation than in transcutaneous NMES. When the mean VAS scores at the same grade of contraction were compared, the VAS scores of electro-magnetic were lower than transcutaneous NMES in both gluteus medius (3.92±1.79 vs. 5.35±2.98, p=0.033) and minimus (4.12±1.85 vs. 5.69±3.00, p=0.046).
Conclusion
Electro-magnetic stimulation induced the contraction of gluteus medius and minimus muscles with less pain than electrical stimulation for the same amount of muscle contraction. These results suggest that electro-magnetic stimulation can replace transcutaneous NMES in deep, large muscles such as gluteal muscles. (J Korean Acad Rehab Med 2008; 32: 417-423)

Key Words: Magnetic stimulation, Neuromuscular electrical stimulation, Pain, Gluteal muscles, Ultrasonographic study