Why physiotherapists should incorporate sensorimotor rehabilitation for neck pain
Musculoskeletal disorders continue to be a global challenge, with neck pain being the most recurrent problem affecting 203 million people in 2020 (1). Physiotherapy for neck rehabilitation has predominantly emphasized movement restoration through manual therapy and Range of Motion (ROM) exercises. Perhaps an overemphasis on pain management without adequately addressing the physical impairments is the reason behind this problem’s recurrence (2). Today, it is well understood that the neck has an essential contribution to sensorimotor functions since it assists the specialised head organs of the eyes, ears, tongue, and nose. Thanks to these functions, humans can efficiently coordinate head and eye movements with the body’s balance during motions to achieve stability and control posture. This multifunctionality emphasizes the need for rehabilitative interventions that go beyond typical cervical ROM exercises to tackle all neck functions, thereby minimizing recurrence rates.
Why we need to address sensorimotor functions when dealing with neck pain
The region of the neck has an important sensorimotor function due to the correlation of deep suboccipital neck muscles with muscle spindles, which is a component of the neuromuscular system, and its profound proprioceptive feedback. This information, alongside that from visual and vestibular systems (also integrated), is communicated into the brain via two reflexes named Cervico-Ocular Reflex (COR) and Vestibulo-Ocular Reflex (VOR).
Let us use the term “movement” for the “movement” of the head or “rotation” about the center of the skull, so movement in the plane of the lower neck. Movement in the plane of the lower neck (head) contributes to elongation of muscle spindles contained in deep neck musculature. Along with the movement of fluids in the vestibular apparatus, head movement activates mechanisms, which are termed as Modified Biomechanical Microscopic Gyroscopes. Based on these mechanisms, signals are sent to eye muscles telling them how fast and in which direction, while gaze fixation about an axis which is termed as “our head”. And which can lead to gaze-independent visual motion perception. This means the eye is aligned along the line of sight which enables “focus”, on the environment we move within.(3)
The cervical-vestibular synergy can be disrupted, also described as eye and space antennae coordination, such as when happen this, leads to neck pain in the head and due to external acceleration forces. Suppose that some delay is caused, for whatever reason, in the signal being sent, in the signal from the neck is being delayed for some reason, due to whiplash injury or chronic neck pain, leads controlling this problem mismatch in input from the hypothetic neck and vestibule, and in output region brain coordinate. This leads to a whole set of symptoms where those symptoms were: unsteadiness, giddiness, difficulty boom focus on visual blur degree of confusion and apparent fatigue.
Pillars of sensory motor function
- The foundational elements of sensorimotor function
- This role of sensorimotor function consists of the following elements:
- Proprioceptive sensory function Oculomotor and gaze control Postural control
Proprioception
This term describes the ability to recognize current body posture or movements and position oneself in the spatial surrounding. Muscle spindles are able to detect muscle length changes thus joint movement, and convey informatory messages regarding the location of our joints in space to the brain (3). In the peripheral joints, we can assess this by comparing one side to the contralateral limb, for example with an ankle sprain, by comparing single leg balance left and right. In the neck, one could use the JPE test where a laser is used in conjunction with a rotational target to evaluate a patient’s ability to locate neutral cervical position while moving between left and right cervical rotation, with eyes shut. This assessment has demonstrated good reliability and validity in assessing cervical spine proprioception.
Oculomotor control (Eye movement)
To assess oculomotor control, the Smooth Pursuit Test (SPT) and Smooth Pursuit Neck Torsion Test (SPNTT) measure control of eye movements toward a target with the neck in neutral position first and then in rotation. These tests help in understanding sensorimotor symptoms like unsteadiness or dizziness which may originate from the cervical spine versus other reasons. If symptoms or control of the eyes is significantly worse with neck rotation compared to neutral, this is more likely diagnostic of issues arising from the cervical spine rather than, for instance, the vestibular system (3).
Postural stability
Maintaining postural stability or balance can prove to be difficult in cases of whiplash and neck pain, both statically and dynamically. In a study, it was noted that 50% of non-dizzy whiplash patients were unable to perform a tandem stance position with their eyes closed due to loss of balance. Almost 75% of dizzy whiplash patients were also unable to perform this task (4).
Sensorimotor rehabilitation
As with most principles, in the rehabilitation approach we need to,’ work on what aggravates the symptoms,’ be it postural stability training, eye tracking control training, proprioception training, or more likely, all of them together.
The previously mentioned goals can be accomplished through basic balance exercises that can be performed with varying bases of support (postural stability), smooth pursuit tracking exercises (oculomotor control), and joint position error training (proprioception) with the laser or a mirror target at home. It is critical for the sensorimotor system to be persistently challenged, regardless of the level of exercise provided, by altering speed, range of movement, amount and type of vision, training frequency and duration. This is vital for day-to-day life demands in neck functionality. This is in fact demonstrated in studies for chronic neck pain (5), which show reduction of pain and disability by 16% on the Neck Disability Index owing to six weeks of proprioceptive and oculomotor exercises. There is evidence supporting a five-week balance training program for its effectiveness in reducing neck pain (6).
Summary
Neck discomfort is arguably the most prevalent form of musculoskeletal pain presented in the clinics and has a high recurrence rate. This indicates that all parts of the neck requiring thorough assessment are taken into consideration, particularly the sensorimotor function of the neck because it plays an important role in daily tasks which include, but are not limited to, the immediate coordination of head and eye movements including keeping a clear visual focus, balance during movement as well as many other activities and tasks. Enhancement of the three pillars i.e. proprioception, control of eye movement, and stability of posture can lead to alleviation of pain in the neck region and reduced recurrence of this problem.
References:
- Collaborators, G. B. D. N. P. (2024). Global, regional, and national burden of neck pain, 1990-2020, and projections to 2050: a systematic analysis of the Global Burden of Disease Study 2021. Lancet Rheumatologyl, 6(3), e142-e155. https://doi.org/10.1016/S2665-9913(23)00321-1
- Treleaven, J. (2008). Sensorimotor disturbances in neck disorders affecting postural stability, head and eye movement control. Manual Therapy, 13(1), 2-11. https://doi.org/10.1016/j.math.2007.06.003
- Jull, G., Falla, D., Treleaven, J., Hodges, P., & Vicenzino, B. (2007). Retraining cervical joint position sense: the effect of two exercise regimes. Journal of Orthopaedic Research, 25(3), 404-412. https://doi.org/10.1002/jor.20220
- Beinert, K., & Taube, W. (2013). The effect of balance training on cervical sensorimotor function and neck pain. Journal of Motor Behaviour, 45(3), 271-278. https://doi.org/10.1080/00222895.2013.785928
- Field, S., Treleaven, J., & Jull, G. (2008). Standing balance: a comparison between idiopathic and whiplash-induced neck pain. Manual Therapy, 13(3), 183-191. https://doi.org/10.1016/j.math.2006.12.005
- Hoy, D. G., Protani, M., De, R., & Buchbinder, R. (2010). The epidemiology of neck pain. Best Practice & Research Clinical Rheumatology, 24(6), 783-792. https://doi.org/10.1016/j.berh.2011.01.019
