What are trigger points and myofascial pain?
Our muscles comprise a very large part of our bodies, and are a very potent source of pain. This pain can be a very effective mimic of many other pain conditions - a very large number of what are described as "trapped nerves" are in fact muscle pains. Sadly, this area of pain is not well understood by many health professionals.
We all get pain in our muscles from time to time, with "cricked necks", the symptoms of 'flu and so on. Muscle pain is also a component of the symptoms associated with many other painful conditions such as back pain and neck pain.
In some people muscle pain can become persistent and can cause considerable problems. In the past this was given names like fibrositis, but now these pains are classed as myofascial pain. Myo- is the prefix that refers to muscle, and the fascia are the layers of connective tissue that surround the muscles.
Many, if not all, of us have areas in our muscles which have a tendency to develop spasm and pain. These are termed latent trigger points or taut bands. Taut bands are common in people without pain, but patients with them are more likely to develop active painful trigger points (TrP's). A latent TrP can develop into an active TrP for a number of reasons. This can happen for a number fo reasons, including Muscle damage or trauma, repetitive contraction or holding abnormal postures (we are not really designed to spend our days in one position in front of a computer screen) or sometimes other painful conditions such as neck, shoulder or back pain. Psychological stress, muscle tension, and physical factors, such as poor posture, can contribute to the process.
There are a number of possible mechanisms for the activation of trigger points. Abnormal tension develops in small areas of the muscle which can develop localised spasm. This can then cause the accumulation of waste products, hydrogen ions and inflammatory chemicals in the muscle fibres, and possibly the tension in the muscle band may impede the blood flow into the muscle causing a reduction in oxygen supply to the muscle. This causes pain, and this pain is transmitted back to the spinal cord along nerves. This can set up a reflex arc rather like a knee jerk, acting through a system called spindle fibres which may cause further muscle spasm. There is evidence of considerably increased electrical activity at the trigger point called end-plate noise - it is not certain whether this represents the increased nerve activity itself or an abnormaility of the connections between the nerve and the muscle. The nerves and their coentral spinal cord connections can become abnormally sensitised, increasing the tendency for the pain and spasm. This can become a self-maintaining vicious cycle. This process is very well explained in a short (6 minute) video on YouTube that you may find helpful, which you can access from here or the link below.
A trigger point (TrP) may feel like a “knot” or “band” in the muscle. The pain from a trigger pont will often not be felt directly around the trigger point itself but may radiate or refer to other areas. These radiation patterns form consistent patterns which with experience can be recognised. For instance, many headaches which refer from the back of the head to behind the eye or into the lower forehead can arise from trigger points at the top of the muscles at the back of the neck, or many patients describe pain and funny feelings into their forearm or hand that is often from a trigger point in the brachioradialis muscle just below the elbow. These referral patterns often do not follow the pathways that nerves travel.
In some cases latent trigger points in the area of radiation of painful trigger points can themselves be activated in a "domino" process.
Much work on trigger points and their referral patterns, and the potential treatments for them, was done in Europe in the 1920's by Kellgren and others, and this was expanded by researchers such as Janet Travell and David Simons, who wrote a major textbook called the Trigger Point Manual. In the 1970's and onwards doctors became very interested in the links between Western knowledge about trigger points and the Chinese system of Acupuncture, and it was demonstrated that many of the trigger points are the same as traditional acupuncture points. Over 70% of trigger points correspond to traditional acupuncture points used to treat pain
Patients with myofascial pain usually report regionalized aching and poorly localized pain in the muscles and joints. They also may report sensory disturbances, such as numbness in a characteristic distribution. Patients often report disturbed or unrefreshing sleep.
How can myofascial pain be treated?
Self management techniques are extremely important. Sedentary individuals are more prone to develop active TrPs than are individuals who exercise vigorously on a daily basis.
There are a number of things that you can do which can help to reduce the symptoms of myofascial pain:
- Exercise regularly. Aerobic fitness of the muscles is a very important factor in helping myofascial pain.
- Improve your posture.
- Reduce your body weight.
- Eat a healthy, well-balanced diet.
- Learn stress-management techniques and relaxation techniques.
- Use proper techniques at work, and during exercise and sports
Treatment for myofascial pain syndrome typically includes medications, trigger point injections (or acupuncture treatments directly to the muscles) or physical therapy. No conclusive evidence supports using one therapy over another.
Trigger point injection treatments (with local anaesthetic, sometimes with added locally acting steroid) aim to interrupt the nerve reflex, relax the trigger point and possibly improve local blood flow, in order to try to break the vicious cycle of maintenance of the pain. Rarely, some practitioners use botulinum toxin (botox) for this. Research has shown that a significant part of the benefit is from inserting the needle into the trigger point. This has led to the development of "dry needling" of trigger points, and interest in how this relates to some acupuncture techniques.
Other physiotherapy techniques directed at the trigger points can involve "spray and stretch" and massage. Sometimes TENS can be helpful.
Medications are variably helpful. As well as painkillers and sometimes antiinflammatory medications, sometimes drugs such as antidepressants can have helpful effects.
Myofascial Pain and Fibromyalgia
Although myofascial pain and fibromyalgia have some overlapping features, they are separate entities; fibromyalgia is a widespread pain problem, not a regional condition caused by specific TrPs.
There is a very useful short video presentation on YouTube by Dr Jonathan Cutner in the causes and treatment of trigger points which you may find helpful
Article about trigger points in the American Family Physician journal
Article on the stoppain website
The article in Wikipedia is very detailed and helpful!
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Pain Service Website, Gloucestershire Hospitals NHS Foundation Trust
Webmaster Dr J G de Courcy, Consultant in Pain Medicine and Anaesthesia
Page updated 15/02/2016