Kristen Sparrow • July 01, 2011
Helene Langevin is a regular at the Society for Acupuncture Research (SAR) gatherings. Her particular interest and expertise is the actual meridians themselves, and the collagen networks that contribute to acupuncture signaling. I was unaware of this study and think it’s interesting. The emphases are mine.
Electrical Impedance of Acupuncture Meridians: The Relevance of Subcutaneous Collagenous Bands
The scientific basis for acupuncture meridians is unknown. Past studies have suggested that acupuncture meridians are physiologically characterized by low electrical impedance and anatomically associated with connective tissue planes. We are interested in seeing whether acupuncture meridians are associated with lower electrical impedance and whether ultrasound-derived measures – specifically echogenic collagenous bands – can account for these impedance differences.
In 28 healthy subjects, we assessed electrical impedance of skin and underlying subcutaneous connective tissue using a four needle-electrode approach. The impedances were obtained at 10 kHz and 100 kHz frequencies and at three body sites – upper arm (Large Intestine meridian), thigh (Liver), and lower leg (Bladder). Meridian locations were determined by acupuncturists. Ultrasound images were obtained to characterize the anatomical features at each measured site. We found significantly reduced electrical impedance at the Large Intestine meridian compared to adjacent control for both frequencies. No significant decrease in impedance was found at the Liver or Bladder meridian. Greater subcutaneous echogenic densities were significantly associated with reduced impedances in both within-site (meridian vs. adjacent control) and between-site (arm vs. thigh vs. lower leg) analyses. This relationship remained significant in multivariable analyses which also accounted for gender, needle penetration depth, subcutaneous layer thickness, and other ultrasound-derived measures.
Collagenous bands, represented by increased ultrasound echogenicity, are significantly associated with lower electrical impedance and may account for reduced impedances previously reported at acupuncture meridians. This finding may provide important insights into the nature of acupuncture meridians and the relevance of collagen in bioelectrical measurements.
Andrew C. Ahn1,2*, Min Park3, Jessica R. Shaw4, Claire A. McManus5, Ted J. Kaptchuk2,6, Helene M. Langevin7
1 Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America, 2 Division of General Medicine and Primary Care, Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States of America, 3 P-pro Korea Co., Ltd., Seoul, Korea, 4 AltThera Health, Boston, Massachusetts, United States of America, 5 Department of Research and Training, Spaulding Rehabilitation Hospital, Boston, Massachusetts, United States of America, 6 Division for Research and Education in Complementary and Integrative Medical Therapies, Harvard Medical School, Boston, Massachusetts, United States of America, 7 Department of Neurology, University of Vermont, Burlington, Vermont, United States of America
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