Predictors of persistent elbow tendonitis among auto assembly workers.

INTRODUCTION: Lateral and medial epicondylitis associated with work activity is a common upper extremity musculoskeletal disorder with a prevalence of 4-30% depending upon the work setting and diagnostic criteria. The influence of treatment, ergonomic factors, medical history, psychosocial variables, and aging on the improvement of symptoms has not been well defined.

METHODS: This was a prospective cohort study of a cohort of 45 workers with active elbow tendonitis for an average of 13 months. Complete resolution of symptoms was the defined outcome measure.

RESULTS: The predictive factors for persistent elbow tendonitis included older age (OR = 1.1, 95% CI: 0.99, 1.33), higher hand repetition level for their job(s) (OR = 2.5, 95% CI: 1.00, 6.25), more deviation from a neutral wrist position during the work activity (OR = 2.0, 95% CI: 0.80, 5.56), and lower perceived decision authority on the job (OR = 0.9, 95% CI: 0.79, 0.98). Other ergonomic, psychosocial, and electrophysiologic measures were not predictive. The models had relatively high sensitivity and specificity. Treatment effects could not be evaluated due to incomplete data available.

CONCLUSIONS: Older workers with jobs requiring more repetition and awkward wrist postures, and less decision authority were less likely to have resolution of their elbow tendonitis.

IMPLICATIONS: Workers at highest risk for persistent elbow tendonitis should be placed at jobs with lower repetition levels and that use more neutral wrist postures. Effective interventions must address both the ergonomic and psychosocial risk factors in a multifaceted approach to this problem.