Why do we get knots in our back muscles, but not in other areas (e.g. arms or legs)?

Why do we get knots in our back muscles, but not in other areas (e.g. arms or legs)?

“Muscle knots,” otherwise known as trigger points, can occur in any muscle of the body when that muscle is used improperly or damaged. With repeated misuse or damage, the affected sarcomeres (contracting fibers) can “lock” into immobility and inflammation of varying levels. Online research of any skeletal muscle of the body reveals images of trigger point pain patterns for that muscle. (Various muscles associated with locations of pain throughout the body are shown here too: National Association of Myofascial Trigger Point Therapists | Symptom Checker)

Current wisdom on this subject is as follows: “The presence of CGRP (calcitonin gene-related peptide) drives the system to become chronic, potentiating the motor endplate response and potentiating, with SubstanceP, activation of muscle nociceptors. The combination of acidic myofascial pH and proinflammatory mediators at the active trigger point contributes to segmental spread of nociceptive input into the dorsal horn of the spinal cord and leads to the activation of multiple receptive fields. Neuroplastic changes in dorsal horn neurons occur in response to constant nociceptive barrage, causing further activation of neighboring and regional dorsal horn neurons that now have lowered thresholds. This results in the observed phenomena of hypersensitivity, allodynia, and referred pain that is characteristic of the active myofascial trigger point.” 1

To put it in simpler clinical terms, an active trigger point that is referring pain will activate (as a result of tissue metabolism and biochemistry altering the nociceptive threshold) associated soft tissue and neural regions through neuroplasticity.

1. An expansion of Simons’ integrated hypothesis of trigger point formation (pg. 474, 1st P.)

What could cause severe, unexplained tooth pain?

While there can be a myofascial (muscle/connective tissue) component to this, it will, of course, be secondary to any significant findings by dental surgeons. This answer presupposes you have already sought a diagnosis from a dental surgeon.

Most commonly, the myofascial diagnosis will be of TMJ (temporomandibular joint dysfunction). Muscles that can cause pain in the teeth (due to myofascial trigger points) include:

Temporalis – a broad, flat muscle on each side of the head, which is a key muscle in mastication:


The “knots”, or trigger points, in this muscle refer (or send) pain to the regions denoted in red – including the teeth. To find if this is the cause of the pain, we’re going to do a bit of trigger point decompression. Heat the temporalis muscle and press on the “x’s” above until they feel like they soften or disappear. The tooth pain should immediately lessen or disappear as well.

Masseter – a quite strong muscle running vertically along the back of the jaw. This picture also images the lateral pterygoid muscle:


To find if the masseter muscle is the cause of the pain, we’ll treat it as we treated the temporalis muscle. First, heat the muscle. Then, hold compression on the areas indicated by the black dots. Do this until the knot feels like it is dissolving or becoming less painful.

Afterward, yawn as wide as you can, comfortably. Then take the muscle through its full range of motion by moving the lower jaw front/back/R/L/in/out/up/down. Yawn once more.

Again, if the tooth pain has reduced or has disappeared, a myofascial issue is probably your primary culprit.

If not, take yourself back to the your dental surgeon’s scans.