title: Ulnar neuropathy and ulnar neuropathy-like symptoms in relation to biomechanical exposures assessed by a job exposure matrix: a triple case-referent study.
abstract: OBJECTIVE
  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.
authors: Danish Ramazzini Centre, Department of Occupational Medicine, Herning Regional Hospital, Gl. Landevej 61, Herning DK-7400, Denmark. susasven@rm.dk
authors: Susanne Wulff
authors: SW
authors: Svendsen
authors: Birger
authors: B
authors: Johnsen
authors: Anders
authors: A
authors: Fuglsang-Frederiksen
authors: Poul
authors: P
authors: Frost
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D012090:Cumulative Trauma Disorders / Q000209:etiology*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009068:Movement; D009784:Occupational Diseases / Q000209:etiology*; D016273:Occupational Exposure / Q000009:adverse effects*; D016017:Odds Ratio; D011187:Posture; D012307:Risk Factors; D013314:Stress, Mechanical; D013312:Stress, Physiological; D014457:Ulna; D014459:Ulnar Nerve; D020424:Ulnar Neuropathies / Q000209:etiology*; D055815:Young Adult