Magnetic stimulation of the quadriceps femoris muscle: comparison of pain with electrical stimulation.
OBJECTIVE
The objective of this study was to compare pain induced by magnetic stimulation of the quadriceps femoris (QF) muscle with that induced by transcutaneous neuromuscular electrical stimulation (NMES).


METHODS
Magnetic stimulation and transcutaneous NMES were applied to QF muscles of 17 normal volunteers. The intensity of each mode of stimulation was increased in a stepwise manner. Peak torque values of isometric contractions of QF muscles and visual analog scale (VAS) scores were recorded at each intensity level. The VAS scores of the two stimulating modalities were compared at the intensity-generating same peak torque values.


RESULTS
The median VAS scores for electrical and magnetic stimulation were 5.7 and 0.3, respectively. The median difference between the VAS scores for electrical and magnetic stimulation was 3.7 (range, 1.7-8.5). The mean of the maximum peak torque obtained from each subject was higher in magnetic stimulation than in electrical stimulation (9.5 +/- 4.8 vs. 4.4 +/- 2.9 Nm).


CONCLUSIONS
Magnetic stimulation of the QF muscle produced less pain at the same level of isometric peak torque than did transcutaneous NMES. Magnetic stimulation is a potential alternative to transcutaneous NMES, especially for persons with intact or residual sensory function.
Han
Tai-Ryoon
TR
Department of Rehabilitation Medicine, Seoul National University College of Medicine, Seoul, South Korea.
Shin
Hyung-Ik
HI
Kim
Il-Soo
IS
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007537:Isometric Contraction; D008280:Magnetics / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000209:etiology*; D010147:Pain Measurement; D010812:Physical Stimulation / Q000009:adverse effects*; D052097:Quadriceps Muscle; D019415:Torque; D004561:Transcutaneous Electric Nerve Stimulation / Q000009:adverse effects*