Musculoskeletal symptoms among young male workers and associations with exposure to hand–arm vibration and ergonomic stressors

Abstract

The overall aim of this study was to explore the association between incident musculoskeletal symptoms in the neck and upper limbs and exposure to hand-arm vibration and ergonomic stressors. The study has a prospective design and data at baseline and follow-up was assessed by self-administered questionnaires. The study population consisted of students that had graduated from vocational high schools in 2001-2003 in northern and western Sweden and a total of 586 men responded to both the baseline and follow-up questionnaires. The mean age was 20.7 (range 19-27) years, and the exposure information included questions regarding hand-arm vibration, postural stress, computer work, mental stress and perception of muscular tension. Musculoskeletal symptoms in the neck and upper limbs were assessed at baseline and at follow-up. Men who reported their daily vibration exposure duration (work and leisure) as more than 1 h at baseline had an increased risk of neck pain in the preceding 7 days at follow-up, when adjusting for all the other exposure variables (PR 3.29, 95% CI 1.02-14.9). Men with a calculated 8-h weighted vibration exposure level [A(8)] above 1.7 m/s(2) had an increased risk of developing neck pain in both the unadjusted and adjusted analyses compared to those with an exposure level below 0.5 m/s(2). Men who reported their daily vibration exposure duration (work and leisure) to be more than 1 h at baseline had an increased risk of neck pain for the preceding 7 days at follow-up. An increased prevalence of neck pain was also observed in individuals with a calculated 8-h frequency weighted vibration exposure level above 1.7 m/s(2) (calculated from data assessed at follow-up) compared to those with an exposure level below 0.5 m/s(2). The increased risks remained when adjusting for postural and mental stress; however the results could still be confounded by other ergonomic and physical load factors not adjusted for in the analyses.