Trigger points are an often-overlooked source of musculoskeletal pain
First described in the 1940s by Dr. Janet Travell—who served as JFK’s personal physician to assist with his back pain treatment—trigger points are a common cause of pain, from chronic back pain and neck pain to headaches and hip pain. These “hyper-irritable” spots located in specific areas on the body can be felt as small, hard knots within taut bands of muscle. When you press on them, they cause not only pain in the immediate area but also “referred pain”—such as headache pain when you push on a spot in the shoulder, or pain in the hip when you touch a trigger point in the lower back. You may experience numbness, tingling, weakness, stiffness and/or restricted movement.
Trigger points are thought to result from direct injuries (such as whiplash) or from chronic overuse or overload of muscles (as can occur from poor posture or carrying a heavy bag); having weak muscles makes you more susceptible. 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 specific patterns of referred pain.
Treatment for Painful Trigger Points
Physical therapists treat trigger points with massage, heat, electrical stimulation and ultrasound. Another technique is to use a cooling spray and then stretch the area. Licensed massage therapists may also do deep-tissue work to help relieve trigger points.
But if these noninvasive approaches (including self-treatment; please see below) are not enough, trigger point injections—performed by a physician, such as a physiatrist or osteopath—may be a reasonable next step.
Trigger point injections involve injecting a substance—usually a local anesthetic—directly into the trigger point to inactivate it. Sometimes “dry needling” is done, in which an empty needle is put into the spot and briefly moved around. The precise mechanism is not known, but the therapy may help by stimulating blood flow, reducing spasms or causing changes in substances that stimulate pain. The needle stimulus might also act as a counter-irritant or, depending on the substance injected, the injections might block certain neurotransmitters or metabolic processes involved with pain.
Trigger Points: What the Research Says
Here’s a look at some of the more recent research on trigger point injections.
A 2009 study from Oregon Health and Science University School of Medicine and other institutions found that injections of a local anesthetic into the trapezius muscle in the shoulder resulted in immediate—but temporary—improvement in range of neck motion and pain levels in people with whiplash.
A 2010 review in the Journal of Foot and Ankle Research found some evidence that trigger point injections were effective for plantar heel pain (both dry needling and/or injections of substances), though it noted that the quality of studies was poor.
A 2009 review of 15 studies, published in Pain Medicine, found that trigger point injections relieved chronic neck, shoulder, back and headache pain, no matter what was injected—though they may not be any more effective than noninvasive treatments such as ultrasound.
One problem with evaluating trigger point injections is that there are few well-designed studies. Placebo-controlled studies on such treatments are difficult, if not impossible, to do, so a placebo effect can’t be ruled out. Plus, most studies have been small, used different treatment protocols and included people with different types of pain, making it hard to compare results. If injections do help, it’s unclear what they work best for, how long the benefits may last, how many treatments are optimal and what drug, if any, is best.
Are trigger point injections safe? Generally yes, when done by an experienced physician. As with any injections, there can be soreness around the site, bruising and infection. More serious are reports of collapsed lungs from injections done in muscles overlying the lung.
Bottom line: Injections should not be used as a first-line treatment for trigger points, but may be helpful as an adjunct therapy, if needed. The key to lasting relief is to find and address the underlying factors that are causing your pain in the first place.
Trigger Points Self-Treatment
To treat trigger points yourself, first see a doctor or physical therapist who can help you identify where they are. It’s not always obvious. You can use various pieces of equipment to massage the trigger points, depending on where the points are located, your dexterity in being able to reach them, and personal preference.
A cheap option is a tennis or golf ball—place it on a hard surface and gently roll your body over it where the trigger point is. You can also use massage balls; some have little nubs. Some devices are shaped like an "S" (Body Back Buddy and Backnobber, for example) or a cane (Thera Cane), which you can use to press on trigger points in your back and neck. Others look like doorknobs (the Knobble) or big jacks (Jacknobber). Foam rollers also work well for trigger points in the back and hips.
Source: Originally published in The University of California, Berkeley Wellness Letter (September 2011)