Myofascial Trigger Points & Dry Needling

Mense S. Muscle pain: mechanisms and clinical significance. Deutsches Ärzteblatt International.
March 2008;105(12):214-219.

How are myofascial trigger points formed?

Pain evoked by myofascial trigger points has a point prevalence of approximately 30%. It is supposed that a muscular lesion damages the neuromuscular endplate so that it secretes an excessive amount of acetylcholine. The ensuing depolarization of the muscle cell membrane produces a contraction knot that compresses the neighboring capillaries, causing local ischemia. The ischemia releases substances into the tissue that sensitize nociceptors, accounting for the tenderness of MTrP’s to pressure.

Differences between muscle pain and cutaneous pain
Muscle Pain

  • Electrical stimulation induces only 1 pain
  • Poorly-localized
  • Tearing, cramping, pressing quality
  • Marked tendency toward referral of pain
  • Affective aspect: difficult to tolerate

Cutaneous Pain

  • Electrical stimulation induces a first and second pain
  • Well- localized
  • Stabbing, burning, cutting quality
  • No tendency toward referral of pain
  • Affective aspect: easier to tolerate

What are the diagnostic criteria of MTrPs?

According to Tough et al, 2007: Variability of Criteria to Diagnose MTrP- Literature Review

  • Tenderness within a taut band
  • Patient pain recognition on tender spot palpation
  • Predicted pain referral pattern
  • Local twitch response


Myofascial trigger points, MTrPs, are areas of taut, band-like hardness in the muscle that are often associated with hyperalgesic zones.1,2,3,4 MTrPs typically develop in response to trauma, muscle overload, or repetitive muscle overload. As MTrPs become compressed, they can elicit a new pain, existing pain, referred pain, autonomic onset, or motor dysfunction.2,3,5,6 technique that occurs when an acupuncture type needle is inserted directly into an MTrP. The needle inserted into the MTrP causes a local twitch response that can disrupt the motor endplate and ultimately have an analgesic effect.7 theory and stimulation of alpha-delta fibers leading to pain suppression. Dry needling has been supported by studies that show it corrects levels of chemicals including bradykinin, calcitonin gene-related peptide, and substance P in the affected muscle.7

From the APTA: Physical Therapists & The Performance of Dry Needling: An Educational Resource Paper

Dry needling can be divided into two categories: superficial dry needling, SDN, and deep dry needling, DDN. Superficial DN enables mechanoreceptors to be activated and paired to slow conducting unmyelinated C fiber afferents with the end result of decreased local and referred pain and increased range of motion. Deep DN enables a local twitch response (LTR) to be elicited in the muscle trigger point while releasing the trigger point and decreasing tenderness locally and distally. Dry needling normalizes the chemical balance and pH within the skeletal muscle as well as restores local circulation. As the  Dry needling, DN, is a trigger point release. Studies have also found that dry needling has an effect on the gate control therapist manipulates the needle, fibroblasts are activated and cytokines and other pro-inflammatory mediators are released to aid in pain reduction.

KIETRYS D, PALOMBARO K, TUCKER M, et al. Effectiveness of Dry Needling for Upper-Quarter Myofascial Pain: A Systematic Review and Meta-analysis. Journal Of Orthopaedic & Sports Physical Therapy. September 2013;43(9):620-634. 

Methods: Four meta-analyses: 1.) dry needling compared to shame immediately after treatment, 2.) dry needling compared to shame or control at 4 weeks, 3.) dry needling compared to other treatments immediately after treatment, 4.) dry needle compared to other treatments at 4 weeks

Results: The findings of 3 studies that compared dry needling to sham or placebo treatment provided evidence that dry needling can immediately decrease pain in patients with upper-quarter MPS, with an overall effect favoring dry needling. The findings of 2 studies that compared dry needling to sham or placebo treatment provided evidence that dry needling can decrease pain after 4 weeks in patients with upper-quarter MPS.

Tough EA, White AR, Cummings TM, Richards SH, Campbell JL. Acupuncture and dry needling in the management of myofascial trigger point pain: a systematic review and meta-analysis of randomised controlled trials. Eur J Pain. 2009;13:3-10. 

Purpose: To establish whether there is evidence for or against the efficacy of needling as a treatment approach for myofascial trigger point pain.

Methods: Seven studies were included. One study concluded that direct dry needling was superior to no intervention. Two studies, comparing direct dry needling to needling elsewhere in the muscle, produced contradictory results.

Conclusion: Direct needling of myofascial trigger points appears to be an effective treatment, but the hypothesis that needling therapies have efficacy beyond placebo is neither supported nor refuted by the evidence from clinical trials.

Cotchett MP, Landorf KB, Munteanu SE. Effectiveness of dry needling and injections of myofascial trigger points associated with plantar heel pain: A systematic review. J Foot Ankle Res . 2010;3:18.

Purpose: Aimed to systematically review the current evidence for the effectiveness of dry needling and/or injections of MTrPs associated with plantar heel pain.

Methods: Randomized and non-randomized control trials where participants diagnosed with plantar heel pain were treated with dry needling and/or injections (local anaesthetics, steroids, Botulinum toxin A and saline) alone or in combination with acupuncture.

Results: Three quasi-experimental trials matched the inclusion criteria: two trials found a reduction in pain for the use of trigger point dry needling when combined with acupuncture and the third found a reduction in pain using 1% lidocaine injections when combined with physical therapy.

DiLorenzo L, Traballesi M, Formisano R, et al. Hemiparetic Shoulder Pain Syndrome Treated with Deep Dry Needling During Early Rehabilitation: A Prospective, Open-Label, Randomized Investigation. Journal Of Musculoskeletal Pain [serial online]. June 2004;12(2):25.

Methods: A prospective, randomized, comparison cohort investigation was performed in the setting of a large inpatient rehabilitation unit with 400 admissions [mainly CVA or head injury] annually. Potential study subjects, who complained of shoulder pain on the hemiparetic side, were enrolled and randomly

assigned to standard rehabilitation treatment plus deep dry needling [Group1] or to standard rehabilitation treatment alone [Group 2].

Results: One hundred and one CVA survivor patients entered the study. Those receiving dry needling, in addition to standard rehabilitation therapy, reported significantly less pain during sleep and physiotherapy. Their sleep was also more restful than that of the non-needled control subjects. The patients treated with dry needling reported a significant reduction in the frequency and intensity of pain and a reduction of pain during daytime and rehabilitation exercises in comparison to the standard therapy alone control group. A statistically significant inverse correlation was found between shoulder pain and mobility.

Hsieh Y, Kao M, Kuan T, Chen S, Chen J, Hong C. Dry Needling to a Key Myofascial Trigger Point May Reduce the Irritability of Satellite MTrPs. American Journal Of Physical Medicine & Rehabilitation. May 2007;86(5):397-403.

Purpose: To investigate the changes in pressure pain threshold of the secondary (satellite) myofascial trigger points (MTrPs) after dry needling of a primary (key) active MTrP.

Design: Single blinded within-subject design, with the same subjects serving as their own controls (randomized). Fourteen patients with bilateral shoulder pain and active MTrPs in bilateral infraspinatus muscles were involved. An MTrP in the infraspinatus muscle on a randomly selected side was dry needled, and the MTrP on the contralateral side was not (control). Shoulder pain intensity, range of motion (ROM) of shoulder internal rotation, and pressure pain threshold of the MTrPs in the infraspinatus, anterior deltoid, and extensor carpi radialis longus muscles were measured in both sides before and immediately after dry needling.

Results: Both active and passive ROM of shoulder internal rotation, and the pressure pain threshold of MTrPs on the treated side, were significantly increased (P < 0.01), and the pain intensity of the treated shoulder was significantly reduced (P < 0.001) after dry needling.

Conclusions: This study provides evidence that dry needle–evoked inactivation of a primary (key) MTrP inhibits the activity in satellite MTrPs situated in its zone of pain referral. This supports the concept that activity in a primary MTrP leads to the development of activity in satellite MTrPs and the suggested spinal cord mechanism responsible for this phenomenon.

References for 1st  paragraph:

  • Hong CZ, Simons DG. Pathophysiologic and electrophysiologic mechanisms of myofascial trigger points. Arch Phys Med Rehabil. 1998;79:863-872.
  • Perez-Palomares S, Oliván-Blázquez B, Arnal- Burró AM, et al. Contributions of myofascial pain in diagnosis and treatment of shoulder pain. A randomized control trial. BMC Musculoskelet Disord. 2009;10:92.
  • Simons DG, Travell JG, Simons LS. Travell & Simons’ Myofascial Pain and Dysfunction: The Trigger Point Manual Volume 1: Upper Half of Body. 2nd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 1998.
  • Travell JG, Simons DG. Myofascial Pain and Dysfunction: The Trigger Point Manual Volume 2: The Lower Extremities. Media, PA: Williams & Wilkins; 1992.
  • Cummings TM, White AR. Needling therapies in the management of myofascial trigger point pain: a systematic review. Arch Phys Med Rehabil. 2001;82:986-992
  • Tough EA, White AR, Cummings TM, Richards SH, Campbell JL. Acupuncture and dry needling in the management of myofascial trigger point pain: a systematic review and meta-analysis of randomised controlled trials. Eur J Pain. 2009;13:3-10.
  • Dommerholt J. Dry needling in orthopedic physical therapy practice. Orthop Pract. 2004;16:15-20.