Arriving at a physical therapy appointment to have a needle stuck deep into the body’s muscles only to leave hobbling and sorer than before doesn’t seem like an effective method for rehabilitation. However, the post-treatment benefits have made dry needling one of the many techniques individuals are using to treat and prevent injury from exercise.

What is Dry Needling?

While wet needling uses hollow needles to inject corticosteroids into muscle [7], dry needling (DN) consists of inserting a fine needle, similar to those used in acupuncture, deep into the muscle without injections. The needle is then twisted and moved around the area without being fully removed from the skin. The needling itself can be uncomfortable, feeling like a pinch, cramp, or deep prick, and can result in local soreness post-treatment. Physical therapists seek to insert the needle into a myofascial trigger point (MTrP) to relieve myofascial pain syndrome (MPS), the most common muscle pain disorder seen in clinical practice [1]. In exercise science, MTrPs are defined as “hyperirritable local point(s) located in taut bands of skeletal muscle or fascia which when compressed causes local tenderness and referred pain” [10]. Potentially caused by muscle overuse [2], this pain is commonly described as having a knot in a muscle and creates localized tenderness, pain to deep touch, and restricted movement [1].

The video above shows a physical therapist performing the dry needling technique on various muscles. Created by Dynamic Physical Therapy, Covington, LA (2013).

Dry needling is used as a rehabilitation technique to decrease the pain MTrPs can cause. The “fast-in and fast-out needle technique” applies high pressure stimulation to the MTrP, often causing a twitch response. These twitch responses are the result of a spinal reflex generated by the activation of nociceptors and mechanoreceptors. These receptors respond to the painful mechanical irritation and stretch the needle causes within the muscle [1]. When this occurs, a single motor unit fires and a visible, isolated contraction – the “twitch” – can be seen. These twitch responses can occur local to the needle or within muscles on the opposite side of the body. This phenomenon has led researchers to believe that the pain associated with MTrPs is due to central nervous system (CNS) changes [1]. 

How is Dry Needling Portrayed in Healthcare?

Healthcare providers, such as MedStar National Rehabilitation Network and ChristianaCare, have been advocates for dry needling. They mention DN is “an effective physical therapy modality…in the treatment of orthopedic injuries” [5] and that it can even be used for preventing pain and injury [4]. There have been many personal accounts of the wonders of dry needling in recovery from nagging injuries. AshleyJane Kneeland, who struggles with muscular pain due to lupus, fibromyalgia, and postural orthostatic tachycardia syndrome, cites DN treatment as relief for her painful spasms and headaches, as well as providing general relaxation [6]. But how effective is dry needling, really? Is there science to back up these claims?

What Does the Science Say?

Elizabeth A. Tough and co-authors performed a meta-analysis in 2009 of seven studies assessing the effectiveness of DN in managing MTrP pain. This study provides an update for the systematic review by Cummings and White, which found no evidence suggesting injections through wet needling generate a better response than dry needling [3]. One study found by Tough et al. suggests DN is more effective in treating MTrP pain than undergoing no treatment, two studies produced contradictory results when comparing DN in MTrPs to DN elsewhere, and four studies showed DN is more effective than other non-penetrating forms of treatment (placebo controls). However, when combining these studies for a sample size of n=134, no statistical significance was found between DN and placebo treatments. 

While the authors conclude the overall direction of past studies trend towards showing that DN is effective in treating MTrP and MPS [10], there is no significant evidence yet. The lack of statistical significance could be due to low consistency in study design for studies included in the meta-analysis, as each employed varying mechanisms for needle placement, depth, and treatment frequencies, along with there being an overall small sample size. Therefore, further studies are required to significantly conclude that DN is effective in MTrP rehabilitation.

Ortega-Cebrian et al. recognized the limitations in previous studies and thus sought to create a significant evaluation of the ability of DN to decrease pain and improve functional movements. The authors use a myometer (MyotonPro, [8]) and surface electromyography (sEMG) to assess the mechanical properties of muscle in subjects (n=20 M) with quadricep muscle tension and pain [9]. 

The MyotonPro allows researchers to quantify muscle tone and stiffness. While no standards exist for describing these parameters with respect to changes after rehabilitation techniques, researchers found the device to be reliable through inter-rater reliability (comparing values of the MyotonPro to another rater). Pain was assessed by subjects using the Visual Analogue Scale (VAS) and a goniometer was used to measure small range of motion (ROM) improvements. DN was performed by one of two experienced therapists until twitch responses ceased [9].

Authors report that DN resulted in statistically significant pain reduction and an increase in flexion ROM. However, the ROM was very small and could be within the range of measurement error of the goniometer. Also, the p-values reported in-text for these parameters do not match the corresponding table which presents a question of the reliability of author reporting. All sEMG parameters, except for decreased vastus lateralis activity, were not significantly changed by DN, as well as all MyotonPro parameters, besides a decrease in vastus medialis decrement (muscle elasticity) and resistance. In a power analysis performed after the study, authors report needing 198 subjects for statistically significant results – much higher than the 20 subjects used [9]. Therefore this study continues the uncertainty in the benefits of DN, but does present significant subject-reported pain reduction.

Is it Worth the Pain?

So is dry needling worth the pain? After being put to the test through experimental studies, there is no clear evidence that dry needling is more beneficial than alternative rehabilitation methods such as wet needling, placebo needling, or acupuncture [9]. However, while the mechanisms of changes in muscles with trigger points due to dry needling are unknown, subjects do report pain reduction. Dry needling should be taken on a case-by-case basis since current knowledge of widespread benefits is limited. Essentially, if dry needling treatment alleviates pain more than other rehabilitation methods and the pain of the procedure is bearable, why not give it a try?

Questions to Consider:

• Would you be willing to try dry needling regardless of uncertainties in the literature?
• Do you believe it is a problem that healthcare providers claim dry needling is effective despite a lack of conclusive evidence?
• What should future studies do to ensure significant results?

References:

[1] Audette, J. F., Wang, F., & Smith, H. (2004). Bilateral Activation of Motor Unit Potentials with Unilateral Needle Stimulation of Active Myofascial Trigger Points. American Journal of Physical Medicine & Rehabilitation, 83(5), 368–374. doi: 10.1097/01.phm.0000118037.61143.7c. 

[2] Bron, C., & Dommerholt, J. D. (2012). Etiology of Myofascial Trigger Points. Current Pain and Headache Reports, 16(5), 439–444. doi: 10.1007/s11916-012-0289-4. 

[3] Cummings, T., & White, A. R. (2001). Needling therapies in the management of myofascial trigger point pain: A systematic review. Archives of Physical Medicine and Rehabilitation, 82(7), 986–992. doi: 10.1053/apmr.2001.24023. 

[4] Dry Needling®. (n.d.). Retrieved from https://christianacare.org/services/rehabilitation/physicaltherapy/dryneedling/

[5] Dry Needling. (n.d.). Retrieved from https://www.medstarnrh.org/our-services/specialty-services/services/dry-needling/

 [6] Dry Needling: The Most Painful Thing I’ve Ever Loved. (2015, March 25). Retrieved from https://www.everydayhealth.com/columns/my-health-story/dry-needling-most-painful-thing-ever-loved/

[7] Dunning, J., Butts, R., Mourad, F., Young, I., Flannagan, S., & Perreault, T. (2014). Dry needling: a literature review with implications for clinical practice guidelines. Physical Therapy Reviews, 19(4), 252–265. doi: 10.1179/108331913×13844245102034. 

[8] Muscle Tone, Stiffness, Elasticity measurement device. (n.d.). Retrieved from 

 [9] Ortega-Cebrian, S., Luchini, N., & Whiteley, R. (2016). Dry needling: Effects on activation and passive mechanical properties of the quadriceps, pain and range during late stage rehabilitation of ACL reconstructed patients. Physical Therapy in Sport, 21, 57–62. doi: 10.1016/j.ptsp.2016.02.001. 

[10] Tough, E. A., White, A. R., Cummings, T. M., Richards, S. H., & Campbell, J. L. (2009). Acupuncture and dry needling in the management of myofascial trigger point pain: A systematic review and meta-analysis of randomised controlled trials. European Journal of Pain, 13(1), 3–10. doi: 10.1016/j.ejpain.2008.02.006.