Effect of Proprioceptive Training Using Head Mounted Laser in Chronic Mechanical Neck Pain

Mechanical neck pain (MNP) is a common condition, affecting 30% to 50% of the general population, and is most prevalent in middle age. It is responsible for reducing the quality of life and one of the leading causes of disability worldwide with annual prevalence of 48.5%. Mechanical neck pain is characterized by several structural and functional features. The causes of MNP include structural and functional impairment of cervical muscles, degenerative changes of cervical spine, arthritis, inflammation, and trauma, abnormal posture, and movements. Current studies have found that one of the main problems in patients with MNP is the impairment of cervical proprioception. decreased range of motion (ROM) and functional ability, greater muscle fatigability and a reduction in the strength and endurance capacity of the muscles.

Despite neck disorders being so common in the population, little evidence supporting effective interventions has been identified. Conservative treatments used to help manage MNP are numerous and include usual medical care various forms of exercise, massage, and acupuncture. Medications, manual therapies, and exercise are the most widely used treatment modalities for MNP. 33% of individuals with neck pain sought care from physical therapy. Physical therapy improves pain, function and patient satisfaction in adults suffering from MNP, improves neck disability index. Physical therapy treatment includes cervical and thoracic spine mobilization/manipulation techniques active and passive exercise, ultrasound, transcutaneous electrical nerve stimulation, patient education. Spinal manipulative therapy (SMT), trigger point dry needling and trigger point manual therapy.

Proprioception is the sense of perceiving self-movement, action of parts of the body and location. It is a term commonly used to describe the ascending information by the afferent receptors towards the central nervous system contributing to the neuromuscular control of movement and encompasses the sensation of joint movement (kinaesthesia) and joint position (joint position sense). Cervical spine has a very delicate proprioceptive system, which signals the position of the head relative to the trunk, coordinates the vestibular and visual systems and it plays a crucial role in controlling posture and balance and is of great importance for spatial orientation. The deficits of Proprioception of cervical spine have been associated with age, pain muscle fatigue, forward head posture, cervical spondylosis, reduced balance control and abnormal posture, decreased neck muscle strength and altered motor control in the cervical spine.

In last two decades the interest in the assessment and treatment of proprioception of the cervical spine has increased exponentially. Cervical joint position sense (JPS) is a major component of proprioception and mainly reflects the ascending input (afferent) of cervical muscle, disc, capsule, and ligament receptors. Proprioception is evaluated using the Joint Position Sense Error (JPSE), which reflects a person's ability to accurately return his head to a predefined target after a cervical movement.

Evidence to date suggests that the management of sensorimotor control disturbances due to chronic neck pain may need to address the primary causes and secondary effects of alterations in proprioceptive activity. A variety of treatments are available for cervical spine proprioception. It includes proprioception training, retraining of deep cervical flexor and extensor muscles, and etiological management of pain, strength training, cervical manipulation and acupuncture and many other conventional therapy protocols. Cervical proprioception training not only improves patient-perceived pain and disability but also has an effect on other aspects of neuromuscular function, specifically the coordination between the deep and superficial cervical flexors and balance.