Current and future advances in practice: cervical spondylosis and mechanical neck pain

Abstract

Cervical spondylosis and mechanical neck pain are generic diagnostic terms, as a more specific diagnosis is often not possible with standard imaging. First-line management is usually conservative, in the form of physical therapies. Rehabilitation is multimodal to address the functional changes that occur in the cervical movement/articular, nervous, neuromuscular and sensorimotor systems in response to pain and pathology. Rehabilitation programmes are patient-specific and include self-management and maintenance programmes in a quest to decrease recurrence rates.

Key messages .

• Neck pain is a common, recurrent disorder.

• Terms such as mechanical neck pain and cervical spondylosis are used, as diagnosing a precise lesion is not possible in most patients.

• Research has identified specific functional deficiencies in articular, nervous, neuromuscular and sensorimotor systems in patients with neck pain.

• Functional deficiencies are identified in a skilled clinical examination; they inform the components of a rehabilitation programme.

• Rehabilitation programmes are multimodal, patient-specific and include self-management and maintenance programmes in a quest to decrease recurrence rates.

Introduction

The Global Burden of Disease Study confirms that neck pain is common worldwide [1]. It affects all ages and is more prevalent in women than in men. Both prevalence and years lived with a disability (YLDs) peak between the ages of 45 and 74 years [2]. Neck pain is ranked 15 out of 371 chronic conditions in terms of YLDs [3]. While an episode may be self-limiting, neck pain is classically a recurrent disorder that incurs significant personal and societal cost.

All structures of the neck are innervated and can be potential sources of nociception [4]. The functional cervical spine requires stability to support the load of the head and to protect the spinal cord and vertebral arteries. It has an abundant source of proprioceptors that, along with the visual and vestibular systems, provide input to facilitate eye and head movement control and postural stability [5, 6]. In accord, the neck has substantial multiplanar movement to subserve vision and to some extent hearing. Yet in addition to head load, the neck is also a base for the attachment of the axioscapular muscles, and thus also carries load of the mobile upper limb. Despite having intricate articular, neuromuscular and proprioceptive systems to perform these diverse functions, it is possibly not surprising that the neck is a common site of pain, considering the static and compressive loads of daily function.

The term mechanical neck pain describes symptoms caused by either an acute overload (trauma) or the accumulation of strains or sprains to the craniocervical joints and ligaments, the zygapophyseal joints, the cervical discs and long ligaments. The term cervical spondylosis describes symptoms associated with degenerative changes and osteophytosis in the cervical discs, endplates, ligaments and zygapophyseal joints [7]. It is well known that these changes are associated with ageing and are not automatically associated with, or causative of pain [8]. In a pain state, the diagnosis of cervical spondylosis is given with other factors coming into play, for example, genetic, metabolic and inflammatory as well as mechanical precipitants [9–13]. In contrast to these general terms, distinct diagnoses of cervical radiculopathy and cervical myelopathy (often a sequel of cervical spondylosis) can be made when spinal nerves or the cord, respectively, are compromised. A diagnosis of a whiplash-associated disorder is made following acute impact trauma, especially related to a motor vehicle crash. These distinct diagnoses are not considered in this review.

Both mechanical neck pain and cervical spondylosis are non-specific terms reflecting the difficulty in identifying an exact lesion in a clinical examination. Radiographic imaging, X-rays, CT applications and MRI are useful and necessary in the diagnostic work-up of serious musculoskeletal and suspected non-musculoskeletal causes of neck pain such as fractures, instabilities, degenerative spondylolisthesis, seronegative or seropositive spondyloarthropathies, suspected cervical arterial dissections, myelopathies, radiculopathies, tumours and infections [14, 15]. However, in mechanical neck pain and cervical spondylosis, imaging is usually unable to identify a definitive pain source. Alternatively, degenerative changes identified on imaging may not accurately reflect the clinical picture. Research into other imageable changes has aimed to identify relevant pathological changes or processes. For example, degenerative Modic changes in the cervical vertebral endplates and subchondral bone have received considerable attention, but there is no consensus for their role in a neck pain state or in their ability to predict a future pain state [16–18]. Other special applications can be useful such as MRI diffusion tensor imaging to confirm the relationship of disc degeneration to the pain state [19] or SPECT to identify painful cervical facet arthropathy [20, 21]. However, such imaging is usually reserved, as necessary, for an interventional work-up.

The first line management of mechanical neck pain and cervical spondylosis is conservative, usually in the form of physical therapies and analgesia as required [22]. While precise pathoanatomy may be unclear, definitive directives for management and rehabilitation strategies for patients diagnosed with mechanical neck pain and cervical spondylosis are based, in large part, on the assessment of the changes in musculoskeletal function which result from pain, strain, degenerative pathology or injury, while also considering and recognizing provocative factors. This review outlines the nature of the changes in physical function, the approaches to patient examination and management. The aim is to emphasize the need for patient-specific, multimodal management, which includes self-management and relapse prevention strategies to address the major issue of the recurrent nature of neck pain.

Changes in physical function with neck pain

Extensive research has been undertaken into the effects of pain and pathology on the function of the cervical musculoskeletal system. This directs a research-informed assessment for a ‘physical diagnosis’. In turn, this physical diagnosis informs the design of a patient-specific rehabilitation programme.

Articular system

Movement of the head and neck involves the craniocervical (C0–2), cervical (C2–7) and cervicothoracic regions (C7–T4). Movement at these regions can be independent (e.g. the yes/no movements of C0–2) or interdependent (e.g. full head rotation requires movement at C0–2, C2–7 and up to a 10-degree contribution from C7 to T4) [23]. All regions need to be considered in a clinical examination. Reduced range of motion is a common presenting feature of neck pain [24–26]. Functionally, neck pain can also be accompanied by a decrease in head velocity and smoothness of movement [27–29], which may reflect altered proprioception, a response to pain or fear of movement or a guarded response to instability [30]. At the segmental level, degeneration in the zygapophyseal joints and cervical discs alters kinematics resulting, at different stages, in excessive (instability) or reduced (hypomobility) segmental motion [31–33].

Nervous system

Distinct conditions such as cervical radiculopathy and myelopathy typically present with changes in conduction of peripheral nerves and spinal cord, respectively, when canals become stenotic because of osteophytosis, a disc fragment or hypertrophied longitudinal ligaments. However, neuropathic pain may present without conduction losses. The nervous system also has mechanical properties. The nerves and nerve beds must be able to slide and stretch relative to their surroundings with various neck and upper limb positions and activities. In normal function, nerves tolerate compression and stretch forces [34]. Inflamed nerves, with or without conduction deficits, can demonstrate increased sensitivity to mechanical stimuli such as nerve palpation [35]. Test movement sequences have been developed to determine whether nervous system mechanosensitivity is contributing to neck and arm pain [36–38] (see Fig. 2—Tests of nerve tissue mechanosensitivity). These are provocative tests, analogous to the straight leg raise for lumbar radiculopathy.

Figure 2.

Components of the physical examination of the cervical region.

Neuromuscular system

Cervical neuromuscular function changes in response to pain and pathology. Changes include a functional reorganization between the deep and superficial muscle layers. The deep cervical muscles such as longus capitis and colli anteriorly and multifidus posteriorly, have reduced activity, while the superficial muscles such as sternocleidomastoid and splenius capitis, demonstrate increased activity [39–42]. Additionally, cervical muscles lose direction specificity [43, 44] and the flexors and extensors co-activate excessively in functional tasks [43, 45]. These changes in muscle behaviour affect motor output, resulting in reduced cervical flexor and extensor strength and endurance [45, 46]. In tandem with functional changes, morphological changes can occur with atrophy and fatty infiltrate, which is more evident in the deep muscles [47, 48].

Neck pain is also often associated with changes in axioscapular muscle function [49–51]. Overactivity or overuse of muscles such as levator scapulae can increase compressive loads on the neck [52], which may contribute to the neck pain [53]. Interestingly, in relation to cause and effect, an experimental pain study determined that neck pain reorganized axioscapular muscle function [54].

Sensorimotor system

In tandem with movement and fine motor control, the cervical spine has a vital role in providing afferent input to the sensorimotor control system. To serve this function, the deep neck muscles, particularly the suboccipital muscles, have the highest percentage of muscle spindles per gram of muscle of all skeletal muscles in the body [5, 55]. Furthermore, there are reflex connections between the cervical, vestibular and visual systems, including the cervico-ocular, cervico-collic, vestibulo-collic, and tonic neck reflexes, which subserve eye and head movement control and postural stability [6, 56, 57]. Unique to this spinal region, the cervical spine has direct connections to the brain, namely to the vestibular nuclei and the superior colliculus, which are considered to be the centre for eye-head co-ordination [58]. This complex neuroanatomy underpins the ability for cervical musculoskeletal dysfunction to disturb sensorimotor control, producing symptoms such as dizziness, unsteadiness and visual disturbances [59, 60]. It is always necessary to consider and differentiate a vestibular cause of such symptoms.

Internal and external factors

Many factors, physical, psychological and social, have been variously identified to contribute to, or compound, mechanical neck pain or a painful cervical spondylitic state. Work, lifestyle, physical activity, mood, sleep all stand to contribute to, or be affected by, neck pain and must be considered in any patient-centred care.

Neck pain will evoke emotional responses and affect mood. Those emotions frequently investigated include anxiety, depression, stress, fear of movement and catastrophization. In many cases, these are normal and expected responses and should not be pathologized [61] and should be addressed in usual care through assurance, empathy, education and management of the pain state. Examination of studies set in primary care or the community confirms that fear of movement and stress to some degree are common, but the frequency of above threshold levels for even mild anxiety, depression and catastrophization is very low [62–67]. In contrast, at least 30% of persons with more advanced neck disorders, requiring consultation with a rheumatologist or orthopaedic surgeon, will present with some degree of depression and anxiety [68, 69].

Provocative factors may be multiple. As an example, a prospective study investigated the recovery trajectories of 50 people presenting with acute neck pain and determined that nine (18%) had an unfavourable recovery trajectory at 6 months [64]. Initial high levels of pain and disability, ongoing systemic inflammation, sleep disturbances and elevated depression, stress and anxiety symptoms were observed in unfavourable outcome trajectories. Of interest, these changes in psychological states appear to be reactive as, at onset of the neck pain, values were in the normal range, and they developed over time. It is necessary to always consider multiple alternative associates with neck pain. For example, sleep disturbance is not uncommon but can be related to depression or mechanical features of the pillow [70, 71].

From the occupational perspective, neck pain in office workers is common, and multiple associates have been explored [72–75]. Physical factors identified can vary from impaired endogenous pain inhibition to poor cervical extensor endurance. Poor work practices play a part, such as working in a flexed static posture, low work task variation and poor workstation set-ups. Likewise, psychosocial features were identified as contributors, including depressed mood, perceived muscular tension, high role conflict and low job control [72–75]. Even though there has been popular acceptance of working from home since the COVID-19 pandemic, it seems it comes with its own set of risk factors for musculoskeletal pain in large part due to its unstructured environment, work practices and social isolation [76, 77]. Although from a work perspective, neck pain is often linked to office workers, no occupation is immune when work involves sustained flexed neck postures as plagues dentists, orthopaedic surgeons, ophthalmologists and optometrists to hairdressers and seamstresses and to the generations fixed to their devices [78–83].

Clinical presentation of cervical spondylosis and mechanical neck pain

Persons diagnosed with cervical spondylosis and mechanical neck pain can present with a variety of symptoms. Neck pain is the prevalent symptom. Complaints of headache are not uncommon. These headaches are often cervicogenic in origin [84], but it must be noted that neck pain is present in 70–80% of both tension-type headaches and migraine [85]. Pain can also present in the upper thoracic region, shoulder and upper limb. Pain mapping has shown that the source for this somatic distribution of head, neck or arm pain can originate in either the zygapophyseal joints or cervical discs [86, 87]. Symptoms such as paraesthesia and anaesthesia can present, but this is more likely associated with a cervical radiculopathy. Notably, symptoms of light-headedness, unsteadiness and visual symptoms are not unusual and can reflect impaired cervical-related sensorimotor control [88–90].

Pain mechanisms can help direct examination and management approaches [91]. While there may be mixed mechanisms, the most common is nociceptive (mechanical or inflammatory) in people diagnosed with mechanical neck pain or cervical spondylosis [92]. Neuropathic pain is prevalent in cervical radiculopathy, while nociplastic mechanisms may come into play with more severe forms of chronic neck pain or unresolved whiplash-associated disorders.

Clinical examination

Patient interview and history

Figure 1 presents an outline of the components of the patient interview and history. It aims in the first instance to confirm the presence of mechanical neck pain or cervical spondylosis and rule out other non-musculoskeletal causes. It is an exercise in listening, to hear the patient’s story with clarifying questions, as needed, to hear the familiar behaviour of mechanical neck pain. A detailed history of the patient’s neck pain disorder elicits whether it is a first episode, a recurrent episodic or persistent disorder, and whether it is progressing or regressing.

Figure 1.

The aims and knowledge sought from the patient interview and history, which informs a differential diagnosis, the physical examination and an individualized management programme

The area of pain provides information on the possible location of the symptomatic segmental level(s) [86]. Careful questioning about the behaviour of symptoms such as dizziness/light-headedness can help, together with the physical examination, differentiate a cervical sensorimotor, versus a vestibular versus a vascular source of symptoms [93]. Cervicogenic headache is a common symptom in the presence of symptomatic upper cervical joint OA or postural strain [94]. Despite comprehensive classification criteria for migraine and tension-type headache—International Classification of Headache Disorders (ICHD-3) [95], differential diagnosis of headache-associated neck pain usually relies on the outcome of a skilled physical examination [96].

Understanding the relationship of symptoms to work or daily activities/positions/movements that provoke them helps confirm the presence of a cervical musculoskeletal disorder. Such knowledge is also fundamental to informing both the physical examination and management plan. A major aim is to remove or lessen these factors going forward towards addressing the burden of recurrent episodes or minimizing any persistent pain. Likewise, understanding the patient’s functional limitations, concerns about their condition, attitudes to their pain and expectations of outcome informs the patient and practitioner alliance as well as the treatment approach. Finally, any X-rays and radiological reports are viewed and ultimately evaluated against the findings of the clinical examination, noting again that imaging is not required to inform diagnosis in mechanical presentations if there are no concerning features.

Physical examination

The nature, direction and extent of the physical examination depend on multiple factors, including the severity of the symptoms, the aggravating activities, and to some extent, the age of the patient, especially those presenting with more advanced cervical spondylosis. The desired outcomes include confirmation that the symptoms have a cervical musculoskeletal source, a provisional diagnosis of the source of symptoms, an analysis of the patient’s functional complaint and identification of impaired functions in the articular, neural, neuromuscular and sensorimotor systems. All findings will inform an individualized treatment plan. Figure 2 presents an overview of the possible components of the physical examination.

Figure 2.

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Figure 2.

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Figure 2.

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The physical examination cannot reliably diagnose a pathoanatomical lesion [97], diagnoses are provisional in nature at best. Nevertheless, in most cases, painful segment(s) can be identified with reasonable accuracy using skilled manual examination (segmental provocation tests) [98–100] and specialized movement tests such as the flexion rotation test (C1–2) [24, 101] and the extension rotation test (zygapophyseal joint pain) [100]. Notwithstanding, it is the ‘physical diagnosis’ which is of utmost importance for directing an individualized rehabilitation programme. The physical examination provides information on the nature and magnitude of movement, articular, neural, neuromuscular and sensorimotor impairments associated with the patient’s complaint to which rehabilitation is directed. Not all tests are relevant for every patient. Rather, the examination is guided by the patient’s presenting complaint, and a pattern is sought between the complaint and physical findings to provide confidence in examination outcomes. Table 1 provides examples of how the physical examination is directed by the patient’s presenting complaint. Functional and physical performance outcomes on which to evaluate treatment effectiveness are selected to complement the patient-reported outcome measures.

Table 1.

Cases to demonstrate the differential use of the physical examination procedures in response to the patient’s presenting complaint

Patient presentation	Provisional diagnosis	Physical examination
Case 1  A 24-year-old patient presents with a first episode, gradual onset upper neck pain after several weeks of intensive computer work. She reports difficulty driving, and complaints of a sharp pain as soon as she turns her head and restricted rotation	Mechanical neck pain C1–2 arthropathy	• Analysis of work postures and practices • Analysis of cervical and craniocervical movements ►  Flexion-rotation test • Manual segmental examination • Tests of craniocervical and cervical flexors, extensors and rotators
Case 2  A 44-year-old patient presents with upper neck pain, which has been increasing over several months. It develops into a headache after 5–6 h of computer work. Her vision becomes blurry and she feels light-headed when the headache is quite intense.	Mechanical neck pain C1–2 arthropathy	• Analysis of work postures and practices • Analysis of cervical and craniocervical movements ►  Analysis of cervicothoracic movement ►  Flexion-rotation test • Manual segmental examination • Tests of craniocervical and cervical and flexors and extensors ►  Tests of scapular muscle control ►  Joint position sense; Movement sense ►  Tests of eye movement control ►  Balance ►  Trunk/head, eye head co-ordination ►  Additional vestibular tests when indicated
Case 3  A 64-year-old patient presents with mid to lower neck pain, which radiates into the lateral upper arm. It is aggravated by lifting and carrying, in particular. He works as a delivery driver for the local post office.	Cervical spondylosis C4–5 degenerative joint disease	• Analysis of work postures and practices • Analysis of cervical movement ►  Neurological examination ►  Tests of nerve tissue mechanosensitivity ►  Nerve trunk palpation • Manual segmental examination • Tests of cervical flexors and extensors ►  Tests of scapular muscle control and strength

The symbol • represents the fundamental tests of musculoskeletal function in common across patients with neck pain disorders; the symbol ► represents the additional tests employed and guided by the patient’s presentation to fully reveal the physical impairments. The findings inform on the necessary rehabilitation strategies.

Rehabilitation

Figure 3 depicts the treatment methods that can be used in rehabilitation of the patient with mechanical neck pain or pain arising from cervical spondylosis. They range from support, empathy and education to methods to achieve pain relief, training of neuromuscular and sensorimotor function as well as self-management strategies and strategies for maintenance and lessening/preventing recurrent episodes into the future.

Figure 3.

Treatment methods for rehabilitation. Selection of techniques is patient-specific and guided by the outcomes of the clinical examination

Clinical practice guidelines as well as systematic reviews, not surprisingly, confirm the superiority of a multimodal approach [22, 102–104]. No one treatment method can address all factors as exemplified by symptomatic relief not necessarily automatically reversing the impaired function in the neuromuscular and sensorimotor systems [105–107]. Impaired function has been shown to persist even in a pain-free state [108–110]. Additionally, non-recovery has been associated with increasing morphological change in muscles [111]. It is not unreasonable to assume that the unresolved impaired physical state can be a factor contributing to recurrent episodes or indeed a persistent pain state. Pain relief is understandably the goal of many patients when seeking treatment and the primary outcome of most clinical trials. However, much of the burden of neck pain is its recurrent or persistent nature. The value/need to retrain and maintain neuromuscular and sensorimotor function is a key feature of management and of patient education to ensure they understand the need to exercise and self-manage in the long term.

Management programmes must be tailored to the individual. The features of patients’ presentations are variable (Table 1), the degree of impaired function is variable and the time for rehabilitation can be expected to be variable. A one-size-fits-all approach cannot be justified based on current knowledge of neck pain. Furthermore, outcome measures must be both symptom and impairment-focused, and the patient must receive adequate treatment dosages to restore neuromuscular and sensorimotor control. Not surprisingly, a recent systematic review analysing the effects and dose–response relationship to outcomes of neck pain and disability demonstrated with low to moderate certainty that higher frequencies and longer duration of sessions significantly improved outcomes of motor control training [112]. While this may mean some extra cost of the initial treatment, it could be argued that the cost burden of neck pain is not in the management of a single episode but in the cumulative costs of management of recurrent episodes or persistent neck pain when there is no attempt to slow disease progression with appropriate rehabilitation.

Maintenance and relapse prevention

As stressed, neck pain is often a recurrent disorder characterized by repeated episodes with variable recovery between episodes [113]. Pain from an episode may resolve, but if disease progression is to be slowed and recurrences lessened or eliminated, provocative factors in work and lifestyle need to be eliminated or minimized in the first instance. Importantly, as discussed, the evidence reveals that musculoskeletal impairments can persist despite pain relief, and they can be perpetuated by subclinical pathology [108–110]. Hence, a maintenance programme is necessary for long-term neck health, but the challenge as with any long-term intervention, is adherence with an exercise programme [65]. The maintenance programme needs to be simple, doable and easily incorporated into daily activities. We advocate two exercises as a basic programme which can be performed hourly and incorporated unobtrusively in daily function [114]. The first is the posture exercise (held for 10 s), which effectively facilitates the deep spinal postural supporting muscles and relevant scapular muscles [50, 115, 116]. It places the spine in a mid-position, repeatedly relieving any adverse loading in a static work posture. The second exercise is the ‘archery’ exercise, which effectively mobilizes the spine from occiput to the mid thoracic spine (Fig. 4).

Figure 4.

Posture and archery exercises. (A) Posture exercise. The patient is taught to grow tall by rolling the pelvis to an upright position, lengthening the back of the neck by trying to lift the base of their skull off the top of their neck and finally gently drawing their shoulder blades together. The position is held for 10 s and repeated at least twice per hour during the working day. (B) The archery exercise. The patient holds an imaginary bow, fixes their sight on the target and draws back as if to shoot an arrow. The exercise is alternated between sides and repeated 5 times, 2 or 3 times per day

A relapse prevention programme must be planned. It should incorporate key elements from the patient’s self-management programme to relieve symptoms and directives to safely reinitiate the exercise programme at the appropriate level. Patients should be advised to restart the self-management programme as soon as they sense that the neck pain is returning. If they cannot self-manage effectively, the patient should seek healthcare before it becomes a full-blown recurrent episode.

Interventional management

Surgical interventions are considered when conservative treatments have failed. Procedures such as discectomy and fusion, disc replacements, foraminotomies, laminectomies address cervical radiculopathies or myelopathies where a specific anatomical lesion can be identified. Interventions for mechanical neck pain and cervical spondylosis are less invasive and are frequently directed to the zygapophyseal joints in the form of diagnostic nerve or joint blocks, radiofrequency neurotomies (RFN) or intra-articular joint corticosteroid injections [117, 118]. Outcomes are better with RFN, especially if the level treated is pre-confirmed with comparative diagnostic blocks [119]. There is evidence that physiotherapists, through their manual examination within a clinical examination, can assist in the identification of the segmental level to be treated [98–100]. This multidisciplinary approach can avoid superfluous diagnostic investigation. There is increasing interest in regenerative medicine therapies, with preliminary evidence of some benefits for intra-articular platelet-rich plasma (PRP) for facet joint pain [120, 121].

Future research

One important area for future research is addressing recurrence, as recurrence is a major contributor to the personal and financial burden of neck pain. Most clinical trials undertaken to date have neck pain (visual analogue scale [VAS]) and disability (Neck Disability Index) [122] as primary outcomes. Little if any research to date has nominated lessening recurrent episodes as the primary outcome. It could be proposed that adequate training of the neuromuscular and sensorimotor systems could lessen recurrence. However, preparatory research is needed to inform the design of such a clinical trial. Currently, there is evidence that specific training can improve neuromuscular and sensorimotor impairments [107, 123–125], but further research is needed into dosage. What is the required dosage of training to ensure ‘normalization’ of these impaired functions? Can it always be achieved and if not in what circumstances will the aim be compromised? Investigations are required into the variables that might adversely impact training. These may be the known predictors of poorer outcome (e.g. high initial pain levels, age and female gender), the nature of the lesion or the presence of existing morphological change such as fatty infiltrate in the muscles.

The last two decades have seen an explosion in research into the biological, psychological and social sequalae of mechanical neck pain and cervical spondylosis. Much is now known and currently, rehabilitation programmes can be implemented on research-informed, evidence bases. Nevertheless, neck pain remains a substantial societal problem, which indicates more is to be learnt, especially in relation to slowing disease progression and lessening the burden of recurrence.

Data availability

No new data were generated or analysed in support of this article.

Funding

No specific funding was received from any bodies in the public, commercial or not-for-profit sectors to carry out the work described in this article.

Disclosure statement: The authors have declared no conflicts of interest.