Nonspecific neck pain is pain that does not show pathognomonic signs and symptoms, [1] when the duration of symptoms is greater than 12 weeks of evolution, it acquires the value of chronicity, being denominated non-specific chronic neck pain (NCNP). [2] It is a common disorder, which generates a great impact and socio-economic cost. [3]
Underlying mechanisms of NCNP relapses are not clear, but it could be associated with a deficit and alteration of the proprioception of the neck muscles that play a decisive role in the cervical joint position, motor control of the head and muscles. eyes, and postural stability (PS). [4-6]
Patients with NCNP usually have alterations in cervical proprioception and PS. May develop symptoms such as dizziness or vertigo. [7, 8] A recently published study shows that patients with NCNP suffer greater sensation of stunning and lack of proprioception than patients with benign paroxysmal vertigo. [9]
Numerous studies downplay the efficacy of manual therapy and therapeutic exercise for pain reduction, cervical disability and associated symptoms, such as dizziness. [10-12] However, there is less evidence of how these treatments, common in the clinical practice, influence PS. [13]
PS is highly influenced by the upper cervical spine and the suboccipital muscles, which is composed of up to 200 neuromuscular spindles per gram of muscle. [14, 15] This upper cervical segment is connected to the central nervous system (CNS), visual and vestibular apparatus and sympathetic nervous system. [16-19] In addition to cervical afferents through the cervico-ocular reflex (COR), the cervico-colic reflex (CCR) and the tonic neck reflex (TNR). CCR activates the cervical musculature in response to stretching, maintaining good head position; [20] COR through the vestibular reflex and the optokinetic reflex; [21] finally TNR added to the vestibulospinal reflex achieves the maintenance of the PS. [22]
The alteration of this proprioceptive complex is not completely defined. Various theories have tried to explain how this system can be altered. Some studies indicate that there is a proprioceptive alteration due to sustained exposure to pain that affects PS through the CNS, these changes may be due to changes in the cortical representation and modulation of the cervical afferent contribution. [23, 24] In addition, some authors begin to point out other psychobehavioral causes that could have a great influence on postural stability, such as anxiety, depression, or fear of movement. [5,6] We must bear in mind that these variables are present in a large number of patients with NCNP. [25, 26]
However, others relate the loss of PS to the dysfunction of the upper cervical spine and its musculature, changes in the cervical mechanoreceptors and the state of weakness of the musculature, [27-29] but not necessarily associated with traumatic events, since this type of alterations have been identified among subjects with NCNP without exposure to trauma. [29]
The area of dizziness of cervicogenic cause is quite unknown and there are several theories about its cause, and there is no consensus on the diagnostic criteria. [30] More research is needed about relationships between neck pain, postural stability and cervicogenic dizziness.
Primary Objetive
The aim of our study is to compare two scientifically approved therapies for the NCNP, one of them with a greater influence on the structural component, and the other one, with a greater component on the central process, to observe differences in the PS of the subjects with NCNP.
Secundary Objetive
Analyze the evolution of cervical pain and disability according to the treatment applied and the relationship with changes produced on postural stability.
Hypothesis
Experimental treatments have a greater beneficial effect on postual stability and pain of subjects with non-specific chronic neck pain than sham treatment. The improvement in postural stability is linked to an improvement in the subject's pain.
Trial Design:
Randomized, controlled, parallel, double-blind, three-arm clinical trial of treatment.