Ulnar neuropathy and ulnar neuropathy-like symptoms in relation to biomechanical exposures assessed by a job exposure matrix: a triple case–referent study
- 1Danish Ramazzini Centre, Department of Occupational Medicine, Herning Hospital, Herning, Denmark
- 2Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark
- 3Danish Ramazzini Centre, Department of Occupational Medicine, Aarhus University Hospital, Aarhus
- Correspondence to Dr Susanne Wulff Svendsen, Danish Ramazzini Centre, Department of Occupational Medicine, Herning Regional Hospital, Gl. Landevej 61, Herning DK-7400, Denmark;
Contributors SWS and PF conceptualised and designed the study and analysed the data. All authors contributed to data collection and interpretation of data. SWS drafted the article and all coauthors revised it critically for important intellectual content. All authors have approved the version submitted for publication.
- Accepted 1 July 2012
- Published Online First 27 July 2012
Objectives We aimed to evaluate relations between occupational biomechanical exposures and (1) ulnar neuropathy confirmed by electroneurography (ENG) and (2) ulnar neuropathy-like symptoms with normal ENG.
Methods In this triple case–referent study, we identified all patients aged 18–65 years, examined with ENG at a neurophysiological department on suspicion of ulnar neuropathy, 2001–2007. We mailed a questionnaire to 546 patients with ulnar neuropathy, 633 patients with ulnar neuropathy-like symptoms and two separate groups of community referents, matched on sex, age and primary care centre (risk set sampling). The two patient groups were also compared to each other directly. We constructed a Job Exposure Matrix to provide estimates of exposure to non-neutral postures, repetitive movements, hand–arm vibrations and forceful work. Conditional and unconditional logistic regressions were used.
Results The proportion who responded was 59%. Ulnar neuropathy was related to forceful work with an exposure–response pattern reaching an OR of 3.85 (95% CI 2.04 to 7.24); non-neutral postures strengthened effects of forceful work. No relation was observed with repetitive movements. Ulnar neuropathy-like symptoms were related to repetitive movements with an OR of 1.89 (95% CI 1.01 to 3.52) in the highest-exposure category (≥2.5 h/day); forceful work was unrelated to the outcome.
Conclusions Ulnar neuropathy and ulnar neuropathy-like symptoms differed with respect to associations with occupational biomechanical exposures. Findings suggested specific effects of forceful work on the ulnar nerve. Thus, results corroborated the importance of an electrophysiological diagnosis when evaluating risk factors for ulnar neuropathy. Preventive effects may be achieved by reducing biomechanical exposures at work.
- General expertise
- Organ system, disease, disease type
- Methodology, speciality
- Methodology, speciality
- Risk assessment
- Materials, exposures and occupational groups
- Physical work
Funding The project was funded by the Danish Working Environment Research Fund (grant no. 13-2007-03/20070014773).
Competing interests None.
Ethics approval The Danish Data Protection Agency, the five Danish administrative regions and the Danish National Board of Health.
Provenance and peer review Not commissioned; externally peer reviewed.