By Hibu Websites
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March 4, 2020
This is probably the most common question asked by patients when dry needling is presented to them as a viable treatment option. The answer to this question is multifaceted. In this post, I will review the peripheral indications and effects of dry needling and will break down and discuss multiple attributes of the treatment. Dry needling is much more than simply inserting an acupuncture needle into a painful trigger point, tight muscular knot, or muscle spasm. Before we understand how the needle itself effects healing and pain levels, it is important to understand the body’s mechanisms that allow these conditions to form in the first place. Trigger points, or knots, can form for a variety of reasons to include acute trauma, repetitive micro-trauma, overuse, and stress. All of these conditions elicit an inflammatory healing response from the body, which creates compression of local blood vessels and decreases circulation and oxygen delivery to the area. This impaired circulation combined with the increased metabolic demands of the hypertonic muscle leads to the depletion of Adenosine Triphosphate (ATP), the cells energy source used to fuel metabolic processes. The “energy crisis” created via the decrease in available ATP creates compensations at the neuromuscular end plate, both pre- and post-synaptically . Pre-synaptically, in the nerve terminal, ATP is directly responsible for the inhibition of acetylcholine (ACh) release. Acetylcholine is a neurotransmitter used at the motor end plate to elicit a muscle’s action potential and therefore a muscle contraction. The depletion of ATP perpetuates the release of ACh, thus perpetuating a muscle contraction in an already hypertonic muscle. Post-synaptically, ATP fuels the calcium (Ca2+) pump, which is responsible for maintaining the electrochemical gradient required to signal skeletal muscle cells to contract. The calcium pump is utilized by opening to allow a stimulus signal to pass and thus allow Ca2+ to flood they cytosol, but also to immediately pump ca2+ out of the cytosol when muscle activation is no longer required. The depletion of ATP mentioned above allows these channels to remain open, therefore, the muscles continually receive the signal to contract. Both of these actions compound upon one another to create a vicious cycle of muscle hypertonicity. When the increased metabolic demands of the hypertonic muscle cell are not met, the cells begin to panic and essentially yell for help. This is achieved by releasing algogenic chemicals such as bradykinins, cytokines, serotonin, histamine, potassium, prostaglandins, leukotrienes, somatostatins, and substance P in order to activiate local nocicepors, to elicit a healing response from the body. Thus, we have the development of a trigger point and the subsequent tenderness and pain associated with it. The effects of prolonged exposure to algogenic substances have been shown to lead to demyelination of local nerves and abnormal nociceptive impulses, which perpetuate the pain cycle. One of the key components of the dry needling treatment is often the aim of eliciting a “twitch response” by inserting the needle directly into a trigger point and tapping onto a sensitive loci. Although this effect is not required for a successful dry needling treatment it is a key component in clearing the excessive build up of ACh from the synaptic cleft and returning the motor end plate to a homeostatic state. Needle manipulation also plays a key role in the effects of dry needling. Multiple techniques are used to achieve a variety of goals. The techniques of pistoning or fanning of the needle are often utilized to create microtrauma and to elicit twitch responses by tapping onto multiple sensitive loci in the desired area. Periosteal pecking is a technique often used at the teno-osseous junction to achieve small amounts of bleeding and microtrauma to a tendon that normally has very little blood supply, in order to elicit a healing response. This technique is performed by a series of rapid tapping motions through the tendon and onto a bony backdrop. Lastly, the needle manipulation technique of twisting the needle has been shown to have numerous effects on local tissues as well as pain relieving properties. Of all of the techniques discussed, only rotation of the needle has been shown to definitively change the appearance of the local connective tissue surrounding the insertion point. Marked thickening of the subcutaneous connective tissue along with deformation of the extracellular matrix have been observed in tissue samples taken after dry needling treatments with needle rotation. Deformation of the extracellular matrix is believed to signal therapeutic effects via the alignment of collagen fibers and fibroblasts. This technique has also been shown to be the only technique that elicits an endogenous opioid release creating true pain reduction from the treatment. If you have any further questions about Dry Needling or feel you could benefit from this treatment technique, please contact Morgan or call our office to speak with one of the therapists at 410-628-0820. Stay tuned for our next newsletter where we will discuss the impact of Dry Needling on the Central Nervous System. References Chu, J. "Does EMG (dry needling) reduce myofascial pain symptoms due to cervical nerve root irritation?." Electromyography and clinical neurophysiology 37.5 (1997): 259-272. Chu, Jennifer. "Twitch-obtaining intramuscular stimulation: observations in the management of radiculopathic chronic low back pain." Journal of Musculoskelatal Pain 7.4 (1999): 131-146. Langevin, Helene M., David L. Churchill, and Marilyn J. Cipolla. "Mechanical signaling through connective tissue: a mechanism for the therapeutic effect of acupuncture." The FASEB Journal 15.12 (2001): 2275-2282. http://www.acupmedvet.com/artigos%20cient%C3%ADficos/Langevin%20et%20al.,%202001b.pdf Langevin, Helene M., David L. Churchill, and Marilyn J. Cipolla. "Mechanical signaling through connective tissue: a mechanism for the therapeutic effect of acupuncture." The FASEB Journal 15.12 (2001): 2275-2282. http://jap.physiology.org/content/91/6/2471.short Langevin, Helene M., et al. "Dynamic fibroblast cytoskeletal response to subcutaneous tissue stretch ex vivo and in vivo." American Journal of Physiology-Cell Physiology 288.3 (2005): C747-C756. http://ajpcell.physiology.org/content/288/3/C747.short Langevin, Helene M., et al. "Subcutaneous tissue fibroblast cytoskeletal remodeling induced by acupuncture: Evidence for a mechanotransductionâbased mechanism." Journal of cellular physiology 207.3 (2006): 767-774. Shah, Jay P., et al. "Biochemicals associated with pain and inflammation are elevated in sites near to and remote from active myofascial trigger points." Archives of physical medicine and rehabilitation 89.1 (2008): 16-23. http://triggerpoint-tutorial.com/pdf/Shah_Biological_milieu_of_MTP.pdf