Trigger points are areas of tension or "knots" that are painful/tender. These points are commonly associated with referred pain, making them distinct from a simple tender points that only cause local discomfort. Estimates of myofascial pain prevalence are 30-85% of pain complaints in primary care settings, with many cases of chronic neck pain being associated with trigger points as well. Although these areas of tension are woeful under appreciated, they likely play a critical role in many common types of pain.
Several proposed mechanisms for the efficacy of trigger point dry needling are through a relaxation of restricted muscle areas and normalizing levels of neurotransmitters/modulators and inflammatory mediators (acetylcholine and bradykinin respectively).
Case Study: 3 patients treated with dry needling for cervicogenic dizziness and 2 reported "full resolution of their dizziness and a significant improvement in their function per standardized outcome measures" with the third not having full resolution, but still reporting improvement. Patients experienced continued results for at least 6 months.
A study randomized a group, ages 35-70 for 3 months, who reported low back pain and had been diagnosed with lumbar disc hernia (LHNP) and had at least one active trigger point (TP), into experimental and control groups. The control group, representing the classical physiotherapy protocol, received a hot pack for 20 min, burst TENS to the lumbar region for 6 sessions of 25 min each, constant ultrasound of the lower back for 10 sessions of 6 min, and pelvic/ lumbar exercises and stretching. The experimental group received 6 sessions of dry needling for 20 min with needle rolled at 10 min and a classic Swedish massage to low back region for up to 10 min. Pain measurements were assessed before and after treatment using McGill Pain Questionnaire. The results showed improvements in both groups after treatment, favoring the experimental group, with an effect size of 1.9 while the control group yielded an effect size of -.5.