Cervical Proprioception Impairment in Neck Pain-Pathophysiology, Clinical Evaluation, and Management: A Narrative Review

Abstract

Neck pain is very common, but most of the causes are unknown, making diagnosis and treatment extremely challenging. Current studies have found that one of the main problems in patients with neck pain is the impairment of cervical proprioception, which subsequently leads to cervical sensorimotor control disturbances. Cervical spine has a very delicate proprioceptive system that plays a crucial role in controlling posture and balance. Cervical proprioceptive impairment in neck pain occurs through a variety of mechanisms. Experimental neck muscle pain induced by injection of hypertonic saline results in inhibition of the activation of painful muscle; chronic neck pain causes structural and functional impairment of cervical muscles; excessive activation of mechanoreceptors in degenerative cervical discs and facet joints produces a large number of erroneous sensory signals. Clinical examinations to assess the link between structural pathology and neck pain have been unsuccessful, opening the way for the development of function-based tests. To date, eight neck sensorimotor control tests have been reported to evaluate patients with chronic neck pain. Although some tests may involve different subsystems (such as oculomotor system and vestibular system), all tests measure sensorimotor control in the neck, and the most commonly used is cervical joint position error (JPE) test. Current studies support the effectiveness of exercises targeting different aspects of sensorimotor function, in particular retraining aimed at improving cervical proprioception and muscle coordination. Based on the available evidence, it is recommended that patients with neck pain should be assessed and managed for cervical proprioceptive impairment and sensorimotor control disturbances.

Keywords: Cervical joint position error; Cervical proprioception; Cervical proprioceptor; Cervical sensorimotor control; Neck pain; Pathophysiology; Rehabilitation.

Fig. 1

Schematic diagram of cervical sensorimotor control

Fig. 2

Cervical joint position error (JPE) test using a laser pointer. The patient is sitting 90 cm from the wall, and the starting point (center of target or reference point) of the laser projection is marked. The patient (blindfolded or closed) performs active neck movement and then returns to the starting position as accurately as possible. The final laser position is measured relative to the starting position (distance or angle). The errors are measured after cervical extension, flexion, lateral flexions, and rotations. Adapted from Treleaven [4] and Revel et al. [67]

Fig. 3

Craniocervical flexion test. During craniocervical flexion test, the patient is positioned supine in crook lying with the neck in a neutral position (no pillow), making the line of the face horizontal. An uninflated pressure sensor is placed behind the neck so that it is close to the occiput and inflated to a baseline pressure of 20 mmHg, which is sufficient to fill the space between the table surface and the cervical lordotic curve, but does not push the neck into the lordosis. The device provides feedback and guidance to the patient to perform the five test phases required, with an additional 2 mmHg per phase and a maximum of 30 mmHg. The patient is asked to hold each position for 10 s. There is a 10-s break between the two stages. The figure shows the starting position (left) and the end position of craniocervical flexion (right). The craniocervical flexion includes the head nodding "yes" movement to keep it in contact with the supporting surface, and the flexion movement mainly occurs in the upper neck motion segments. Adapted from Jull et al. [104] and Falla et al. [106]