Chronic neck pain is the third most common pain complaint, according to the American Osteopathic Association, affecting one in four Americans surveyed. It may result, for example, from injuries, accidents, spinal issues, or regularly sleeping in a bad position. But often no specific underlying cause can be found, in which case it’s called chronic nonspecific neck pain. There is now evidence that “trigger points,” sometimes collectively referred to as myofascial pain syndrome, may play a perpetuating if not causal role in at least some instances of chronic nonspecific neck pain.
Trigger points are hyper-irritable spots that can be felt as small, hard knots within taut bands of muscle. When you press on them, they are usually quite painful—but they also always elicit pain in one or more other areas, called referred pain. In the case of neck pain related to myofascial pain syndrome, the trigger points are located in the neck, shoulders, or upper back. (Trigger points can be found in many skeletal muscles, but we are limiting our discussion here to those related to neck pain.)
Trigger points—which often restrict movement and can cause muscle weakness, tingling, and numbness—are thought to stem from mechanical factors, notably sustained muscle contractions (as canoccur when working at a computer for long hours with poor posture) or chronic muscle overload (for instance, if you regularly tote heavy bags).
A 2016 study from Spain in the journal Pain Medicine looked at the prevalence of myofascial pain syndrome in 224 people who had neck pain for at least six months, not attributed to systemic disease,nerve impingement, tendinopathy, trauma, or other established causes. Trigger points were detected in all participants, almost always in the trapezius muscle.
Still, trigger points remain something of a mystery. For instance, there is no general agreement as to precisely what they are or how they produce their specific patterns of referred pain.
Treating trigger points
If you have chronic neck pain that has not been attributed to any underlying cause, ask your doctor to test for trigger points in your neck, shoulders, and upper back. If your primary care doctor is not experienced in this, he or she can refer you to a physiatrist (a specialist in physical medicine and rehabilitation) or to a physical therapist for evaluation.
Treating the trigger points may provide substantial or even complete relief of neck pain. Options include certain types of deep tissue massage (be warned, this may hurt a lot), stretching (sometimes with application of a cold spray), heat, electrical stimulation, ultrasound, and, if these are not enough, trigger point injections (usually done with a local anesthetic).
Another possible treatment is dry needling, which involves a health care provider inserting an empty needle (no medication) into the trigger points and moving it in and out rapidly. There’s some evidence for its effectiveness, including another study by the authors of the previously mentioned study, published in the journal Pain in 2016, which included 128 people with chronic neck pain attributed to trigger points.
The patients received either dry needling plus passive stretching or stretching only (the control group) from a physical therapist, several times over two weeks. Both groups benefited, but the dry needling group had greater improvements in neck pain, pain threshold, range of motion, and strength. Moreover, the improvements were maintained at a six-month follow-up.
A smaller study in the Journal of Manual & Manipulative Therapy in 2016, again by the same authors, similarly found benefit from dry needling of trigger points in the trapezius muscle in office workers with trigger-point-related neck pain.
But not all studies have shown dry needling to have benefits beyond physical therapy alone—and if it does help, the mechanism is not known. Some ideas are that it may work mechanically (perhaps as a counterirritant) to reduce sustained muscular contraction at the trigger points, by stimulating blood flow, or by causing the release of certain chemicals locally.
Patient expectations may have played a role in the studies, however, meaning that there may have been a placebo effect from getting this extra treatment and attention. (As with acupuncture, it’s hard to do double-blind placebo-controlled studies on dry needling because the appropriate placebo would be sham needling that is indistinguishable from the real procedure, so that neither the practitioners nor participants know which is which.) And it’s unknown what effect dry needling would have on its own, since the studies combined it with stretching.
Still, as the researchers concluded, their results are in line with previous research and support the use of dry needling in managing chronic nonspecific neck pain associated with myofascial pain syndrome.
Also see Dealing with Painful Trigger Points.