12/02/2024
The role of the nerve receptors in the joints of the cervical spine emphasizes the importance of this area's normal function. Function impaired by the aging process, trauma, or structural imbalance may have a wide adverse influence throughout the body. The joints of the cervical spine, like all synovial joints throughout the body, have an array of mechanoreceptor (corpuscular) and nociceptor (non-corpuscular) nerve endings. This includes both the facet and Luschka articulations. The Type I receptors (low-threshold, slow adapting) have powerful reflexogenic influences on the cervical, limb, jaw, and extra-ocular muscles. These receptors are very important in postural and kinesthetic sensation. The Type II receptors (low-threshold, rapidly-adapting) monitor the phasic changes of the cervical and limb muscles.
Some of the afferent branches from the Types I and II articular receptors ascend and descend within the spinal cord to synapse in the motoneuron pools of the neck and upper and lower limb muscles. Branches primarily from the upper three or four cervical spinal joints ascend in the propriospinal tracts to be distributed in the motoneuron pools of the jaw and external ocular muscles.
Loss of cervical motion, whether joint dysfunctions/subluxations, from a cervical support collar or pathology such as osteoarthritis, ankylosing spondylitis, or trauma, often causes the patient to report a feeling of postural instability and unsteadiness of gait. This is especially true when there is poor illumination, reducing the influence of the visual system.
