At present, acupuncture's effects are thought to take place primarily by way of the nervous system.1 For example, some neural effects of acupuncture have demonstrated the release of central nervous system endogenous pain-inhibitory substances and the activation of autonomic nervous system reflexes.2,3 Recent studies based on the effect of mechanical load on soft tissues have shown that acupuncture may have an effect on soft tissue similar to the effects of soft-tissue methods that utilize hands and instruments.
Langevin, et al.,4 hypothesized, based on histological observations of the effects of needle insertion in humans, that the mechanical stimulation of the needle on the connective tissue could be responsible for mechanotransduction of signals with far-reaching effects on the body. When a needle is inserted into muscle/connective tissue and rotated, there is a winding of connective tissue around the needle. This creates a deformation of the extracellular matrix (the interstitial tissue surrounding our cells), transmitting a signal to cells such as fibroblasts that are extremely abundant in connective tissue. They found that the fibroblasts become aligned with collagen fibers and change shape.5 Changes were shown to occur within one minute in the fibroblasts when the needle was rotated, compared to just inserting the needle. According to the authors, "These observations suggest that the mechanical signal created by acupuncture needle manipulation can induce intracellular cytoskeletal (cell structure) rearrangements in fibroblasts and possibly in other cells present within connective tissue, such as capillary endothelial cells."
Mechanical load signals have shown to cause cell contraction, migration and protein synthesis. Stimulation of fibroblasts causes synthesis of collagen and the extracellular matrix that houses the collagen: "Furthermore, the contraction of fibroblasts alone would cause further pulling of collagen fibers, resulting in a 'wave' of matrix deformation and cell contraction spreading away from the needle through interstitial (fascia) connective tissue." The authors hypothesized that the mechanical activation of signal pathways by deformation of connective tissue could be responsible for changes in gene expression and modification of the composition of the extracellular matrix and cell contraction.4
It is an established fact that signal pathways are activated by mechanical load. According to Banes, et al., most of the literature on mechanical load demonstrates that cells detect mechanical deformation as tension, compression, shear or fluid flow, and organelles provide physical connections between the outside and inside of the cell, linking to signaling pathways that convey mechanical stimuli information to the nucleus.6 Langevin, et al.,4 determined that the winding up of the needle increased the pullout force necessary for removing the needle, which correlated with measurable changes in the connective tissue architecture. The greater pullout force necessary correlated with increased tissue disruption. They also found that this "needle grasp" was more enhanced at acupuncture points than non-acupuncture points. Acupuncture points are usually found along cleavage lanes between muscles, or between muscle and bone or tendon, where there is usually more connective tissue.
Is it possible that Graston Technique®, ischemic compression, Active Release®, friction massage, Neuromuscular Re-educationsm and other methods would be more effective if increased pressure coupled with a rotatory stimulation of the tissue was emphasized?
References
- Stux G, Pomeranz B. Basics of Acupuncture, Springer-Verlag, Berlin, 1995.
- Andersson S. The functional background in acupuncture effects. Scand. J Rehab Med suppl. 29, 1993:31-61.
- Ernst M, Lee MHM. Sympathetic vasomotor changes induced by manual and electrical acupuncture of the joint visualized by thermograph. Pain 21, 1985:25-31.
- Langevin HM, Churchill DL, Wu J, Badger GJ, et al. Evidence of connective tissue involvement in acupuncture. The FASEB Journal express article 10.1096/fj.01-0925fje. Published online Apr. 10, 2002.
- Langevin HM, Churchill DL, Cipolla MJ. Mechanical signaling through connective tissue: a mechanism for the therapeutic effect of acupuncture. The FASEB Journal 15;2001:2281.
- Banes AJ, et al. Mechanical forces & signaling in connective tissue cells. Current Opinion in Orthopedics 12(5):2001.
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