I have a similar conversation multiple times a week with neck patients regarding this question: “Is that a knot?” I work on many patients with neck pain. Patients come in with all types of diagnoses such as cervicalgia, spondylosis, radiculopathy, Levator scapulae syndrome, myofascial pain syndrome, and upper back pain to name a few. Ironically, many of these patients have the same type of “knots.” And they all ask, “what is a knot?”
Well, a knot can be termed a few different ways and can actually be a couple of different things. One of the most common is what is called a trigger point, some professionals might call it an acupoint. Tigger points are found in the muscle belly and are a small sum of contractile fibers in a partial state of contraction. They are in this state of constant contraction typically due to a dysfunction in the nerve impulses sent to that section of contractile tissue.
However, the knots that I find around the spine are hands down due to a pathological thickening around the cervical zygapophyseal joint (or facet joints for short). They are not trigger points. Some massage therapists and even some physical therapists working around the spine might be tempted to call these knots, trigger points, but that would be an injustice. The cervical facet joint can be the primary cause of neck pain either directly or indirectly. Frequently, a restriction in the facet joint indirectly causes a sequalae of events that triggers a painful condition in which the the actual facet joint restriction can go unnoticed. This is going to be tough to explain, so I will start by explaining the anatomy of the facet joint.
The fact joints are two of the five articulation points between the vertebrae of the cervical spine. The most important of the remaining three would be the disc joint and the other two joins are inconsequential but for the sake of completion are called the uncovertebral joints (not pictured). The facet joints are responsible for the congruence of each vertebral connection and guides the direction of each vertebrae’ s movement. In the cervical spine the facet joints lie more angled front to back, in the thoracic spine the facets have a slightly flatter orientation front to back, and in the lumber spine they are more vertical. Typically, I have found that facet joint dysfunction, mainly restriction, is found exclusively in the cervical and thoracic spine and much less likely in the lumbar spine. Interestingly, this is because of both the size of the discs and the orientation of the facets. In the lumbar spine the discs are larger and the vertebrae are much further apart. Whereas in the cervical spine and to a lesser degree in the thoracic spine the discs are smaller and therefore the facets are much closer together.
Biomechanically, the facet joints predict the articulation direction of each vertebrae. It is the rudder of the “ship” if you will. It steers how each facet moves on the other one. The facet joint is made up of the inferior facet of the vertebrae above it and the superior facet of the vertebrae below it. In between the two boney facets is a layer of articular cartilage on each the inferior and superior facets as well as a meniscus in the middle. During certain spinal movements the articular facets either get compressed, glides or they can gap open. This occurs such that if the facet on the right-side compresses then left-side facet gaps open. The example below is left rotation (pictures A & B). As an aside, compression happens during cervical spine extension as well as side-bending. However, for the sake of this discussion, we will talk only about rotation to the left. In “Picture B” below the right-side facet joint is compressed and the left-side is gapping during left rotation of the head. After a certain amount of wear and tear, or maybe a one-time trauma, or after several years of abuse, then the compression of the facet joint can cause it to become impacted. Most of the time, I would use the word restricted or even sometimes the word “stuck”.
In the example above, the right-side facet joint during left rotation is impacted or “stuck” (Picture C). When impaction (restriction) occurs, that facet joint does not continue to operate as normal. The Spinalis, Semispinalis and superficial layers of the Multifidus muscles that produce the movement attempt to contract and try to move the joint. However, no movement occurs, the impaction at the joint does not allow it. This generates at least two problems. One, it fashions a new axis of rotation for the vertebral movement, as seen in the above diagram in “Picture C.” This new axis forms because the impacted joint forces the movement to hinge on itself instead along the back side of the vertebral body. This new axis of rotation subsequently puts a lateral shear force on the disc and thus more stress, wear, and tear that it really should not have. If this underlying facet joint is not released from its impaction (restriction) then overtime the disc will have accelerated degenerative changes.
Secondly, if the impaction persists for a fair amount of time then the facet joint starts to develop inflammation, scar tissue and muscle spasm. Palpation of the facet joint at that time would will feel thick, raised and knotty. This thickness will not resolve with just releasing the impacted joint but some moderate level of soft-tissue work around the facet would be needed as well. After several treatments then the facet would start to feel suppler and the proper biomechanical movement would begin to be restored. I do caution you not to be too aggressive at trying to restore the facet impaction with too much force like deep tissue massage from a massage therapist, vigorous stretching, or using any sort of long axis rotational manipulation techniques such as chiropractic. That could lead to inflammation in the disc and possible herniation. I have seen this more times than I should during evaluations with clients that have tired chiropractic and deep tissue massage. If you have questions about what to do with “knots” around your spine and/or think you might have a facet impaction contact a Fellowship trained manual physical therapist to steer you in the right direction.