Pathophysiology Section
Neck pain is the 4th leading cause of disability in the US (Cohen, 2015) and can cause individuals to have difficulty with driving, working and participating in social endeavors (Hoy et al., 2010). The prevalence of neck pain has been reported to be between 15-50% each year, and peaks with middle-aged adults. Females have a higher precedence of neck pain than males. There is a positive relationship between obesity and neck pain, possibly because of increased mechanical stress and weaker muscles (Cohen, 2015). Additionally, there are many factors that can contribute to cervical pain such as occupation, poor work environment, sedentary lifestyle and psychosocial factors (Hoy et al., 2010). Specifically, office and computer workers have a 57% incidence of neck disorders in the US (Côté, 2004). Risk factors for neck pain in an office include increased hours spent on the computer, prolonged static postures and poor ergonomic work environment (Ehsani, Mosallanezhad, and Vahedi, 2017). Due to the functional limitations that the neck pain can cause, it is important to identify and target the individual contributing factors in order to treat the patient.
The source of neck pain can be neurogenic, involving a peripheral nerve, mechanical, or secondary to another cause (Cohen, 2015). Differentiating the type of neck pain will guide the clinician’s treatment, prognosis of the patient and overall plan of care. Cervical postural dysfunction is a type of mechanical impairment. Pain occurs due to the innervation of nociceptive sensitive structures of the cervical spine, such as ligaments, muscles and walls of blood vessels. Loaded positions combined with postural malalignment, including forward head posture (FHP), stretches these sensitive structures which can lead to compression of the nerve ending and causes the person to feel pain. The pain is diminished when the mechanical stress is removed, such as when a person changes position. Increased and continuous stress to the system can cause a breakdown of tissues and may lead to an inflammatory response in the body, even though no apparent trauma or injury occurred. Therefore, it is important to address postural dysfunction before it progresses and causes more damage to the body and person.
A specific type of cervical postural syndrome is upper crossed syndrome (UCS), which was introduced by Dr. Vladmir Janda. This syndrome occurs when deep neck flexors and lower scapular stabilizers are lengthened and weakened, and the opposite anterior chest muscles and posterior neck muscles are shortened and become tight (Joshi and Srivastava, 2016). This syndrome follows a cycle of poor posture and repetitive movements causing muscle tightness and weakness which leads to scapular winging, elevation and protraction of the shoulder and FHP (Dutton, 2016, p.326). FHP is defined as increased extension of the atlanto-occipital and atlanto-axial joints and increased flexion of the lower cervical spine (Kim et al., 2018). One measurement of FHP is the craniovertebral angle (CV angle), which is the angle of the intersection of a horizontal line from the spinous process of C7 and a vertical line from the tragus of the ear. The CV angle of a person with good postural alignment is between 55-65° and the CV angle of a person with FHP < 55° (Dalawale and Pimpale, 2018). The smaller the angle, the greater the severity of the FHP. There are several dysfunctions associated with FHP and UCS including tension headaches, decreased respiratory function due to increased thoracic flexion narrowing the area of the lungs (Joshi and Srivastava, 2016), and shoulder-neck pain (Shih et al., 2017). Improving posture can decrease these associated impairments and prevent future occurrences (Shih et al., 2017).
