The Mechanics of Acupoint Tapping
The process by which tapping on acupoints produces electrical signals involves a well-established mechanism called "mechanosensory transduction," by which cells are able to convert a mechanical stimulus (e.g., needling or tapping) into electrical activity (Gillespie & Walker, 2001). At least some acupuncture points have also been shown to have less electrical resistance, and thus greater electrical conductivity, than adjacent points (Li et al., 2012). The path by which the signals generated by acupoint stimulation move through the body has been mapped, based on imaging studies, as being along the fascia, the soft tissue component of connective tissue, which forms a whole-body matrix of structural support (Bai et al., 2011; Finando & Finando, 2012). A strong correspondence has, in fact, been found between the pathways on which acupuncture points are purportedly situated (described as "meridians" in acupuncture theory) and the body's interstitial connective tissue (Langevin & Yandow, 2002). While a major criticism of acupuncture has been based on the difficulty of establishing correspondence between putative meridian pathways and anatomical structures (e.g., McCaslin, 2009), these imaging studies are beginning to resolve that question (Langevin & Wayne, 2018) and shed light on other puzzles. For instance, because of the semiconductive properties of the collagen comprising much of the connective tissue, the signals produced by tapping on acupoints can plausibly be sent to specific areas of the body more rapidly and directly than if they needed to travel through the nervous system, neuron-to-synapse-to-neuron (Oschman, 2003).