What is Trigger Point Therapy?

Trigger point therapy is a bodywork technique that involves the applying of pressure to tender muscle tissue in order to relieve pain and dysfunction in other parts of the body. Sometimes massage and trigger point therapy are performed together.

Trigger points are described as hyperirritable spots in skeletal muscle that are associated with palpable nodules in taut bands of muscle fibers. Trigger point researchers believe that palpable nodules are small contraction knots and a common cause of pain. Compression of a trigger point may elicit local tenderness, referred pain, or local twitch response. The local twitch response is not the same as a muscle spasm. This is because a muscle spasm refers to the entire muscle entirely contracting whereas the local twitch response also refers to the entire muscle but only involves a small twitch, no contraction.

The trigger point model states that unexplained pain frequently radiates from these points of local tenderness to broader areas, sometimes distant from the trigger point itself. Practitioners claim to have identified reliable referred pain patterns, allowing practitioners to associate pain in one location with trigger points elsewhere. Many chiropractors and massage therapists find the model useful in practice, but the medical community at large has not embraced trigger point therapy. Although trigger points do appear to be an observable phenomenon with defined properties, there is a lack of a consistent methodology for diagnosing trigger points[1] and a dearth of theory explaining how trigger points arise and why they produce specific referred pain patterns.

Trigger point therapy is also called myofascial trigger point therapy. It was developed by Dr. Janet Travel in the United States in the 1940s.

What are Trigger Points?

Trigger points are areas of tenderness in a muscle. There are two basic types of trigger points: active and latent.

Active trigger points cause muscular pain and will refer pain and tenderness to another area of the body when pressure is applied. Latent trigger points only exhibit pain when compressed, they do not refer pain to other areas of the body. Latent trigger points are believed to be one of the causes of stiff joints and restricted range of motion of old age.

Trigger points may be associated with myofascial pain syndromes or fibromyalgia. Trigger points are very common. They are also referred to as muscle knots.

Trigger points differ from acupressure points. Acupressure points are concentrations of energy or blockages of the body's energy pathways. Trigger points are physical phenomena that can be felt by touch.

The pain caused by trigger points may be the biggest cause of disability and loss of time in the workplace.

What Causes Trigger Points?

Trigger points have several causes. Some common causes of trigger points are: birth trauma, an injury sustained in a fall or accident, poor posture, or overexertion.

What is the Purpose of Trigger Point Therapy?

The purpose of trigger point therapy is to eliminate pain and to re-educate the muscles into pain-free habits. After several treatments, the swelling and stiffness of neuromuscular pain is reduced, range of motion is increased, tension is relieved, and circulation, flexibility and coordination are improved.

Myofascial pain syndrome

The main innovation of Travell's work was the introduction of the myofascial pain syndrome concept (myofascial referring to the combination of muscle and fascia). This is described as a focal hyperirritability in muscle that can strongly modulate central nervous system functions. Travell and followers distinguish this from fibromyalgia, which is characterized by widespread pain and tenderness and is described as a central augmentation of nociception giving rise to deep tissue tenderness that includes muscles. Studies estimate that in 75-95 percent of cases, myofascial pain is a primary cause of regional pain. Myofascial pain is associated with muscle tenderness that arises from trigger points, focal points of tenderness, a few millimeters in diameter, found at multiple sites in a muscle and the fascia of muscle tissue. Biopsy tests found that trigger points were hyperirritable and electrically active muscle spindles in general muscle tissue.

Qualities of trigger points

Trigger points have a number of qualities. They may be classified as active/latent and also as key/satellites and primary/secondary.

An active trigger point is one that actively refers pain either locally or to another location (most trigger points refer pain elsewhere in the body along nerve pathways). A latent trigger point is one that exists, but does not yet refer pain actively, but may do so when pressure or strain is applied to the myoskeletal structure containing the trigger point. Latent trigger points can influence muscle activation patterns, which can result in poorer muscle coordination and balance.

A key trigger point is one that has a pain referral pattern along a nerve pathway that activates a latent trigger point on the pathway, or creates it. A satellite trigger point is one which is activated by a key trigger point. Successfully treating the key trigger point often will resolve the satellite and return it from being active to latent, or completely treating it too.

In contrast, a primary trigger point in many cases will biomechanically activate a secondary trigger point in another structure. Treating the primary trigger point does not treat the secondary trigger point.

Activation of trigger points may be caused by a number of factors, including acute or chronic muscle overload, activation by other trigger points (key/satellite, primary/secondary), disease, psychological distress (via systemic inflammation), homeostatic imbalances, direct trauma to the region, radiculopathy, infections and health choices such as smoking.

Trigger points can appear in many myofascial structures including muscles, tendons, ligaments, skin, joint capsule, periosteal, and scar tissue. When present in muscles there is often pain and weakness in the associated structures. These pain patterns in muscles follow specific nerve pathways and have been readily mapped to allow for identification of the causative pain factor. Many trigger points have pain patterns that overlap, and some create reciprocal cyclic relationships that need to be treated extensively to remove them.

Diagnosis of trigger points

Trigger points are diagnosed by examining signs, symptoms, pain patterns and manual palpation. Usually there is a taut band in muscles containing trigger points, and a hard nodule can be felt. Often a twitch response can be felt in the muscle by running your finger perpendicular to the muscle's direction; this twitch response often activates the "all or nothing" response in a muscle that causes it to contract. Pressing on an affected muscle can often refer pain. Clusters of trigger points are not uncommon in some of the larger muscles, such as the gluteus group (gluteus maximus, gluteus medius, and gluteus minimus). Often there is a heat differential in the local area of a trigger point, and many practitioners can sense that. In 2007, a paper was presented describing images of trigger points taken by modified MRI.

Misdiagnosis of pain

The misdiagnosis of pain is the most important issue taken up by Travell and Simons. Referred pain from trigger points mimics the symptoms of a very long list of common maladies, but physicians, in weighing all the possible causes for a given condition, rarely consider a myofascial source. The study of trigger points has not historically been part of medical education. Travell and Simons hold that most of the common everyday pain is caused by myofascial trigger points and that ignorance of that basic concept could inevitably lead to false diagnoses and the ultimate failure to deal effectively with pain.