Hand-arm vibration syndrome in Swedish car mechanics
- 1Department of Occupational and Environmental Medicine, Sahlgrenska Academy, Göteborg University, Göteborg, Sweden
- 2Occupational Health Services, Göteborg, Sweden
- Correspondence to: Dr L Barregard, Department of Occupational Medicine, Sahlgrenska Academy, Göteborg University, S:t Sigfridsgatan 85, S-412 66 Göteborg, Sweden; lars.barregard{at}ymk.gu.se
- Accepted 16 August 2002
Abstract
Aims: To assess the occurrence of hand-arm vibration syndrome (HAVS) in Swedish car mechanics, and the relation between HAVS and duration of exposure.
Methods: A total of 806 mechanics answered a questionnaire on vascular and neurological symptoms, and exposure to vibrations. Mechanics with symptoms, and some mechanics without symptoms, were invited to a clinical examination, including also a timed Allen test. Vascular and neurological symptoms were classified using the Stockholm Workshop scales. The mean daily exposure (mainly using nut-runners) was 14 minutes and the mean exposure duration, 12 years. Published data have shown vibration levels in nut-runners of about 3.5 m/s2.
Results: In the questionnaire, 24% reported cold induced white finger (WF), 25% persistent numbness, and 13%, reduced grip force. The clinical examination showed a prevalence of vibration induced white finger (VWF) of about 15%, mainly in stage 2, and after 20 years, of 25%. A survival analysis showed similar results. We found that the International Organisation for Standardisation (ISO) model underestimates the risk of VWF. The incidence after 1975 was 19 cases per 1000 person-years. Slow refill times in the timed Allen test were common (15% had a refill time of >20 seconds), and associated with the presence of VWF. The clinical examination revealed neurological symptoms in the hands in about 25% of subjects, mainly at stage 2. After 20 years, the prevalence was 40%. The questionnaire items on WF and numbness both showed likelihood ratios of 13.
Conclusion: HAVS is common among Swedish car mechanics in spite of short daily exposure times. This underlines the need for preventive measures.
- CTS, carpal tunnel syndrome
- HAVS, hand-arm vibration syndrome
- ISO, International Organisation for Standardisation
- QST, quantitative sensorineural testing
- WF, white finger
- VWF, vibration induced white finger









