Irritability of inflamed or injured facet joints is high in terms of easily and quickly flaring up into pain when subject to unusual stresses, but then later can react badly even to normal stresses. The typical symptoms are local tenderness and aching throughout the neck, across the shoulder blades, over the neck/shoulder area and upper arms. All this pain can cause the muscles to go into spasm which compounds the problem by facet joint compression with consequent enhancement of the pain and joint forces. Some patients have severe neck muscle spasm which presents as tight, hard muscles.

Muscle spasm disturbs the whole function of the neck, reducing its ability to iron out sudden stresses. Muscles which would naturally switch off after a time remain contracted and tense the neck, making it more sensitive to jars and sudden movements. As the neck becomes more irritable the person consciously becomes more guarded with their neck movements and their upper arm activities, magnifying the problem again. The interplay of neck and thoracic posture has important mechanical consequences for painful problems in the neck as it throws abnormal stresses on the cervical segments.

If the thoracic spine is much straighter than it typically is the reciprocal curves of the thorax and the neck can be lost, forcing the cervical spine to sit more vertically upon the thorax, without its typical lordosis. The lordosis distributes weight between the anterior discs and the posterior joints, preventing abnormal disc loading which can cause early degeneration and then secondary facet changes. Problems can also occur when the opposite anatomical misalignment occurs with an increased thoracic curve forcing a reciprocally increased cervical curve to maintain the face in a horizontal position.

Increased cervical and thoracic spinal curves result in a typical poor posture, particularly in sitting, of the head poking well forwards of the shoulders and trunk, requiring high levels of force to be developed in the supporting musculature of the neck to keep the head held in space. The biggest and strongest muscle is the upper trapezius and when it is working too hard it can develop local tender and painful spots which can refer pain elsewhere and are known as trigger points. The lower trapezius muscles can correspondingly become underactive, leading to a reduced level of control of the shoulder, neck and arm complex.

Our necks can be injured in a series of different methods, either suffering sideways forces involving twisting or shearing or longitudinal compression forces, or both. The outer disc walls are vulnerable to such injuries and so begins the sequence of degenerative events in the disc, the pain itself followed by both inhibition and overwork of the muscles, loss of range of motion and limitation of disc nutrition. Pain worsening leads to the extensor muscles of the neck increasing the vertical pressures by over contracting, pushing the vertebral levels together more closely. Segmental disc narrowing may lead to stiffness but can also cause hypermobility of the segments as the disc, having lost water content and ligamentous integrity, loses its role in stability.

Segmental degeneration is often accompanied with time by the growth of osteophytes, outgrowths of bone, which sprout from the edges of the abnormal segment. An abnormally moving segment is likely to suffer this change and this may be an attempt by the bodys systems to improve the stability of the segment by splinting it with bone along the soft tissues nearby. The nerve roots exit from the intervertebral foramens each side of the spine and there are vulnerable to impingement at times by osteophytic outgrowth, causing severe nerve root pain in the arm. Surgical management of such impingement may be required in some people but overall this condition is not amenable to surgery.

The facet joints of the neck are now vulnerable once the affected segment has stiffened with degenerative changes. Narrowing of the discs causes the facet surfaces to suffer increased contact forces as the segment closes down on itself. The movements which should be performed by the gradually more abnormal and stiff facet are passed onwards to other parts of the spinal system above or below the stiff segment. Facet joints which are normal can then start to suffer from the abnormal forces and change.