The knot explained!

The role of trigger points in muscle pain…

Trigger points are felt as small, tender nodules and painful bands in skeletal muscles. These knots are hyperirritable spots. When muscles work in an eccentric fashion, that is a contraction occurs while the muscle lengthens, damage occurs within the muscle cells. The reason why these trigger points develop is because a neurotransmitter, Acetylcholine, is released in excess, which then causes a persistent, localized muscle contraction. This muscle contraction compresses blood capillaries which then reduces blood flow. Lower amounts of oxygen and glucose is then delivered to the muscle and an energy crisis is created. As a result, a number of pain sensitizing substances are released which activate nerve receptors that respond to pain. The muscle is unlikely to relax and thus, a vicious cycle is created.

The presence of a local twitch response, referred pain or reproduction of symptomatic pain increases the certainty that a trigger point is present. A local twitch response may occur when a trigger point is stimulated with a needle. The response is a spinal reflex and is unique to trigger points.

Trigger points are classified as either active or latent. With active trigger points, there are spontaneous complaints of pain locally or referred, which may be present at rest or during movement. A latent trigger point does not cause pain without being stimulated.

The onset of trigger points can be related to acute, chronic or repetitive muscle overload. A couple of pain problems where trigger points are identified include radiculopathies, joint dysfunction, disc pathology, tendonitis, craniomandibular dysfunction, migraines, tension type headaches, carpal tunnel syndrome, computer related disorders, whiplash, spinal dysfunction and pelvic pain and other urologic syndromes.

Trigger points can be treated by physiotherapists with the use of manual therapy or dry needling. The goals of treatment are to break the cycle of feedback, release the tension in the point and to restore uniform lengths in the affected muscle fibers. Manual therapy is a basic form of treatment. Physiotherapists use slow sustained stretching techniques to allow the muscle to release due to the “stickiness” of its molecules. A series of contract-relax stretching is then used in order to facilitate in re-setting muscle length. Trigger point pressure can also be released by applying gentle persistent local pressure against the palpable tissue barrier in the trigger point. Massage techniques, such as friction massage and kneading are particularly useful for de-activating trigger points.

Martine Human – Physiotherapist

0825743165