Physical and psychological workload in men with and without low back pain.

Current and retrospective physical and psychological workload was studied in 148 mean, 45-55 years old. The men represented three groups with respect to low back health status: Healthy low back (Group 1, n = 36), intermittent low back pain (LBP) (Group 2, n = 91) and chronic LBP (Group 3, n = 21). The methods used were a self administered questionnaire, a rating scale of perceived exertion, and blind expert assessment built on a classification of job titles. Group 1, the back-healthy subjects, had been less exposed to heavy physical work than subjects with intermittent LBP (Group 2) and chronic LBP subjects (Group 3) through their whole working-career and in their present work (p < or = 0.05, p < or = 0.01). Group 2 tended to be significantly less exposed in their present work than Group 3 (p < or = 0.06). Non-neutral working postures were reported more often in Groups 2 and 3 than in Group 1 (p < or = 0.05, p < or = 0.001). Both groups 2 and 3 perceived present and earlier work to be more strenuous than Group 1, with respect to the low back (p < or = 0.000). Subjects in the healthy low-back group had lower values in the qualitative demand index ("too difficult working tasks" and "too great responsibility") than subjects in Groups 2 and 3 (p < or = 0.01). This study indicates that more attention should be given to the individual's perception of physical workload.