There are five physiological mechanisms which can be used to explain how medical acupuncture works. Each can be used for a different purpose which is why anyone using medical acupuncture must be able to make a conventional medical diagnosis and have an understanding of the underlying pathology to be effective when using a medical acupuncture approach.
The different mechanisms require variations in the treatment technique and so this needs to be tailored to the individual patient.
This blog will discuss the first of the five mechanisms, the local effects:
The local effects refers to the ability of acupuncture to activate specific sensory nerve fibres in the skin and muscle. Needling near the sensory nerve endings sets off action potentials (nerve impulses) which spread around and along with the local network of nerve fibres – this is called an axon reflex.
Various substances are released as a result including adenosine and calcitonin gene-related peptide (CGRP) both of which cause local blood vessels to dilate, causing an increase in local blood flow. The blood flow is also increased in the deeper tissues, which encourages tissue healing. Adenosine also has a mild local pain-relieving effect, while CGRP may also promote healing and repair.
More recent research has shown the acupuncture needle stimulus to trigger the release of myokines within the muscle tissue, mainly when electrical stimulation is applied (electro-acupuncture). Myokines help reduce muscle atrophy, improve muscle mass and promote muscle healing.
Lastly, the mechanical stimulus of the needle may help disrupt the dysfunctional motor endplate, which has been proposed to be the driver of muscular myofascial trigger point activity. In combination with the other local effects described above, the disruption may assist with the deactivation of sensitive and pain referring trigger points (aka muscle ‘knots’). When medical acupuncture is used to treat trigger points, it is often referred to as Dry Needling.
Summary: Acupuncture promotes local healing in the tissues and can be used to deactivate trigger points.
By Simon Coghlan MSc, BScPhysio, DipMedAc
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