Tractor-driving hours and their relation to self-reported low-back and hip symptoms.

Tractor driving might be one causal risk factor in the incidence of low-back and hip symptoms among farmers. Information on the annual exposure to tractor driving and its distribution among different work operations is scarce. The purpose of this study was to quantify the total and the annual time driving tractors among Swedish farmers and its distribution into different work operations, and to investigate the risk of low-back and hip symptoms in relation to tractor driving within different work operations. The data were collected from a questionnaire study sent to all farms with acreage more than 10 ha in a county in Sweden. Farmers having farming and/or forestry as their main occupation in 1995 were included in the analysis. The annual tractor-driving time and the percentage distribution within different work operations were calculated for females, males, the total group and four production groups. The risk calculations for low-back and hip symptoms from the variables related to tractor driving were performed on the total group. The results showed that the mean annual tractor-driving time was 472 h. Ploughing was the single most time-consuming work operation but it had no influence on the risk for low-back or hip pain. The results showed that some of the variables investigated related to tractor driving influenced the risk for low-back and hip symptoms.