Brachial plexopathy: a case–control study of the relation to physical exposures at work

BACKGROUND Work-related upper limb disorders constitute a diagnostic challenge. However, patterns of neurological abnormalities that reflect brachial plexus dysfunction are frequent in limbs with pain, weakness and/or numbness/tingling. There is limited evidence about the association between occupational physical exposures and brachial plexopathy. METHODS 80 patients with brachial plexopathy according to defined criteria and 65 controls of similar age and sex without upper limb complaints were recruited by general practitioners. Patients and controls completed a questionnaire on physical and psychosocial work-exposures and provided psychophysical ratings of their perceived exposures. The exposures of cases and controls were compared by a Wilcoxon rank sum test. Odds ratios and dose-response relationships were studied by logistic regression. RESULTS Whether assessed as the extent during the workday or days/week, most physical exposures, in particular upper limb posture and repetition, were significant risk indicators with clear dose-response relationships. These findings were supported by psychophysical responses that also identified perceived work pace and the use of force as risk indicators. The identified psychosocial relations were limited to measures reflecting physical exposures. CONCLUSIONS While the identified risk indicators have previously been associated to upper limb symptoms as well as to diagnosed disorders other than brachial plexopathy, this study indicates an association between physical and work-exposures and brachial plexopathy. Longitudinal studies should be conducted in order to exclude bias from information and selection, both of which may occur with the applied case-control design.