Evidence based cervical spine rehabilitation
Neck pain is a common musculoskeletal disorder with a lifetime and annual prevalence of 70% and 23% respectively (1,2). Recurrence is common, 25% will report pain within 1 year and 30% will develop chronic pain (3). Systematic reviews and meta-analysis confirm the effectiveness of exercise for relieving and preventing neck pain (4–6); however, this does not necessary address the sequelae of altered neuromuscular control and inhibition of the deep neck musculature, specifically the Longus Capitus, Longus Colli and Semispinalis Cervicis (7,8).
Moreover, this increases the activation of superficial muscles, such as the Sternocleidomastoid, Anterior Scalene and Splenius Capitus (7,9). These findings appear to be universal in those with neck pain regardless of the diagnosis, as demonstrated in cervicogenic headaches, whiplash, work related pain and idiopathic neck pain (7,10–12). Furthermore, the presence of altered neuromuscular control is associated to severity of pain (11). EMG studies reveal these muscles also have reduced directional specificity (13). Delayed onset of muscle activity, fatty tissue infiltrate, altered muscle fibre type proportion have also been demonstrated (14–17).
Importantly, these adaptations and deficiencies do not improve spontaneously following a reduction or resolution of pain (11). Studies comparing manual therapy, exercise, manual therapy combined with exercise, and control group illustrate that all interventions are effective at reducing pain; however, only specific exercise improves activation of the deep neck musculature (18).
The cranial-cervical flexion test is accurate at identifying patients with reduced activation of the Longus Capitus and Colli, an inability to reach and maintain a pressure of 26mmHg is a positive test (7). Training these muscles produces an immediate reduction in pain, reduces anterior head drift in sitting, increases muscle activation time and improves long-term neck pain and disability (18–21). Similar findings are being exposed for assessing and training Semispinalis Cervicis in neck extension dysfunction and the Sub Occipital muscles when indicated (22).
Lack of pain control may have a detrimental effect on improving neuromuscular training (23). Therefore, introducing pain management modalities should be considered concurrently with exercise therapy. Combined manual and exercise therapy have demonstrated higher efficacy than exercise alone (18).
Neck muscle strength
Strength and force steadiness are typically deficient in patients with cervical pain (24–26). Utilising specific neck strength exercises is effective at improving these deficiencies (27). Although, it is important to understand that lack of strength and subsequent improvement through training is also intimately related to fear and increased confidence (28). Strength training should be considered with chronic neck pain patients as this may reverse fatty tissue infiltrate and muscle fibre type proportion. However, reversal of these findings has not been demonstrated in the cervical region, extrapolation from other areas indicate its efficacy (29).
A patient that describes dizziness, unsteadiness, difficulty focusing, altered orientation in space and blurred vision that is related to neck pain or headache should strongly implicate altered sensorimotor function (30). True vertigo is uncommon in the cervical spine. Assessment of joint position error, gaze stability and eye-head co-ordination is efficient at identifying this. Training cervical sensorimotor system of proprioception, gaze stability and eye-head co-ordination has been shown to improve joint position error and pain (31,32). Cervical-cranial flexion training also improves joint position error but not as effectively as proprioceptive training (33).
What about shoulder muscles
The axioscapular muscles have attachments on the cervical spine and therefore can affect movement and loading patterns. Previous studies indicate that patients neck symptoms increase during upper limb tasks, altered function of the axioscapular muscles have been proposed as a contributor (34,35). Moreover, manipulating the position of the scapular can improve pain, range of movement and proprioception, therefore rehabilitation may be justified by symptom modification procedure (34,36).
Overall, it is important to understand there is no “one size fits all” rehabilitation in the cervical spine. Research demonstrates the greatest improvements in an intervention is found in patients that demonstrate deficits on examination (37). Therefore, success relies on the adoption of evidence-based interventions to address deficiencies specifically identified on examination. Studies focused on specificity in rehabilitation in the cervical spine show promising results. Neck specific vs general physical activity demonstrate 5.3 times reduced disability and 3.9 times reduction of pain on a 12 month follow up (38).