RT Journal Article
SR Electronic
T1 Ulnar neuropathy and ulnar neuropathy-like symptoms in relation to biomechanical exposures assessed by a job exposure matrix: a triple case–referent study
JF Occupational and Environmental Medicine
JO Occup Environ Med
FD BMJ Publishing Group Ltd
SP 773
OP 780
DO 10.1136/oemed-2011-100499
VO 69
IS 11
A1 Susanne Wulff Svendsen
A1 Birger Johnsen
A1 Anders Fuglsang-Frederiksen
A1 Poul Frost
YR 2012
UL http://oem.bmj.com/content/69/11/773.abstract
AB 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.