Prevalence of, and risk factors for, musculoskeletal disorders of the neck and upper limbs

Neck and upper limb pain are common symptoms. However, such symptoms may arise from specific upper limb disorders such as rotator cuff tendinitis, lateral epicondylitis, or carpal tunnel syndrome, or as a result of more diffuse non-specific regional pains. Epidemiological research in this field had been hampered by the lack of an agreed system of classification until 1997 when a UK workshop derived consensus case definitions for most of these disorders. Working from these new criteria, the objectives of this thesis were to develop and test a workable examination protocol suitable for use in epidemiological research and then, using this new tool, to describe the prevalence, impact, risk factors and natural history of specific and non-specific upper limb disorders in the general population. Initial methodological work was performed in order to evaluate the repeatability and validity of the Southampton examination protocol. In two separate studies, among 88 hospital-based subjects and among 97 community-based subjects, the protocol was shown to have good repeatability and excellent validity against the gold standard. A cross-sectional survey of all 9698 working-aged adults registered with two general practices in Southampton was then undertaken. Every subject was mailed a questionnaire, enquiring about demography, risk factors and recent symptoms in the neck and upper limbs. All symptomatic respondents were invited to attend for interview and examination and upper limb symptoms were classified according to the National criteria. Additionally, a longitudinal study was undertaken of a cohort of 350 individuals identified cross-sectionally, who were re-contacted by postal questionnaire after an interval of 20 months. Every subject with persistent upper limb symptoms was invited to attend for repeat examination. The one-week prevalence of neck and upper limb pain lasting a day or longer in the past 7 days was 43%, and one-half of individuals reported functional disability as a result of their symptoms. Approximately one-third of those with pain were found to have specific upper limb disorders and specific disorders were associated with greater levels of disability than non-specific pain. Specific upper limb disorders tended to be associated with mechanical workplace exposures involving stress local to the site of that diagnosis, but non-specific pain was most strongly associated with prolonged abnormal neck posture. Neck and upper limb pain persisted in the majority of subjects (79%) at follow-up after 20 months. More importantly, specific disorders were observed to track within individuals so that those with specific disorders at baseline were considerably more likely to have specific disorders at follow-up.