Neck pain is operationally defined as pain extending from above the spines of the scapula to the superior nuchal line, with or without radiation to the head, arms, or trunk [19]. Radiation of pain to the upper limbs or head may be pain referred from somatic structures in the neck or implicate the involvement of peripheral nerve tissue ranging from irritation to nerve root compression, the latter being termed cervical radicu­lopathy [30].

Neck pain can occur as a consequence of systemic diseases such as inflammatory ar­thritis or tumors but by far the most common causes are benign where the origin of the pain is related to somatic structures of the cervical spine. The precise anatomical structure, if there is one, cannot usually be determined and thus the neck pain is defined as nonspecific. Neck pain can occur as a result of a traumatic injury, for example, a motor vehicle crash, fall, or sports incident, and in these cases it is defined as whiplash-associated disorders (WAD). It can also be nontraumatic in nature with no specific event or injury being attributed to its onset. It has been argued that this differentiation should not be made and that neck pain be considered and classified as one condition [19] but some evidence suggests differences in the underlying biological and psychological processes between neck pain of traumatic and nontraumatic origins [6,12,50] and these will be further discussed later in this chapter.