Acupuncture Science 9: Mechanical Signaling

Part 9: Mechanical signaling as a mechanism for Acupuncture

To date much of the acupuncture mechanism of action has been related to the nervous system, linking it to the medical physiological concept of ‘‘Gate control theory of pain’. Based on this theory acupuncture needling or electrical stimulation is said to activate relevant neural pathways. However this theory does not explain other non-pain related effects, nor does it correlate with the Traditional Chinese Medicine (TCM) acupuncture concepts.

Acupuncture involves the process of needle insertion. In TCM acupuncture, depending on the result intended the needle is inserted to a particular depth at a chosen acupoint site. This is followed by its manipulation to attain the ‘Arrival of Qi’ (De Qi). De Qi is experienced by the patient as soreness, numbness or a feeling of fullness around the needle point. Alternatively, in ancient texts for practitioners it is described as “seems a fish bites on fishing pulling the line downward” and may be felt as a needle grasp. This is an essential step in the therapeutic process. However, practitioners may not readily attain ‘De Qi’, and will therefore need to resort to needle manipulation. Basic needle manipulation techniques include; lifting and thrusting, and twirling or rotating movements. If Qi still fails to arrive then further manipulations techniques may be used. These can be;

  • Pressing, the skin along the meridian line to promote the circulation of Qi and blood.
  • Plucking (lightly), the handle of the needle to stimulate the Qi.
  • Scraping, the needle with the finger to spread needing sensation.
  • Shaking, to strengthen the needling sensation.
  • Flying, is to twirl the needle quickly three times to promote needle sensation.
  • Trembling, is a quick and small lift-thrust movements to cause vibration and promote Qi.

Lagevin et al (2001) has refuted suggestions that muscle contraction is the cause of the needle grasp (De Qi), as the same effect is also seen in areas where skeletal muscle is absent. Instead, they suggest that the cause is mechanical coupling between the needle and winding of the local tissue around it. They established this through histological examination of rat tissue explants with acupuncture needle manipulation which showed marked thickening of the connective tissue layer around the needle, while changes in the dermis or muscle were not observed. Acupuncture needle insertion and manipulation is thought to have both local and distal therapeutic effects. These effects are based on;

  • Mechanical coupling of the needle to the connective tissue due to surface tension and electrical attraction between the two.
  • Winding of the tissue around the needle during insertion and manipulation
  • Generation of a mechanical signal through pulling of the collagen fibers during the manipulation process
  • Mechanotransduction of the signals into the cells

Mechanotransduction activates changes in the fibroblasts and/or other cells, which in turn starts a variety of downstream effect including; cell secretion, modification of extracellular matrix, amplification and transmission of nerve signals travelling along the planes of the connective tissue into the spinal cord and brain. At the same time there is modulation of the sensory input due to changes in the connective tissue environment.

Finally, within the phenomenon of mechanotransduction TCM acupuncture and its effects can have some scientific validity. It can be attributed as the common mechanism through which the effects of acupuncture needling are realised. De Qi is an essential contributory process which determines the overall effectiveness of the treatment, whilst downstreaming effects resulting in cellular changes explain the longer term effects of acupuncture. This is an important clinical understanding which could have considerable implications in changing our knowledge base of biological mechanisms and the future applications within medicine.

In Part 9, our Final in this series we will look at the phenomenon of  Mechanotransduction as a mechanism for acupuncture.

Part 1: How Does Acupuncture Work?
Part 2:  Qi: Vital Energy, Life Force
Part 3: Five Elements Theory
Part 4:  Chinese Diagnosis
Part 5: Integrating Western Physiology with TCM Philosophies
Part 6: TCM Meridians
Part 7: Meridians & Fascia
Part 8: Arrival of Qi (De Qi)

References: 
  1. Stux G, Berman B, Pomeranz (2003). Basics of acupuncture, 5th  edition.  Springer Berlin Heidelberg, New York.
  2. Xinnong C (2000). Chinese acupuncture and moxibustion, 5th edition. China Books & Periodicals Inc, San Francisco.
  3. Dong J (2013). Evidence-Based Complementary and Alternative Medicine. 2013:153148.
  4. Eachou Chen (2008). Does qi travel on meridian like thin membrane energy transmission through the fascia? JAIM 4(2): 84-86.
  5. Teppone M, Avakian R, Karneev. “Arrival of qi” phenomenon during ehf – puncture.
    1st International Symposium on Quantum Medicine. November 17-22, 2001, Bled, Slovenia, p. 116-118.
  6. Chen CW, Tai CJ, Choy CS et al. Wave-Induced Flow in Meridians Demonstrated Using Photoluminescent Bioceramic Material on Acupuncture Points. Evi Based Complement Alternat Med (2013). 2013:739293.
  7. Langevin HM, Churchill DL, Cipolla M J (2001). Mechanical signaling through connective tissue: a mechanism for the therapeutic effect of acupuncture. FASEB J. 15:2275–2282
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