The survey charted leg length discrepancy as a risk factor for back pain in both sitting and standing work. It was assumed that lower limb discrepancy is an independent determinant of back pain, especially when standing at work. The aim of this study was also to give guidelines to occupational health services on how leg length discrepancy should be taken into account with people who suffer from back pain. The connection between leg length discrepancy and back pain was investigated both by cross-sectional and by intervention design. The intervention part included persons standing at work who had, in the cross-sectional study, been diagnosed with a leg length discrepancy that could be a significant factor in terms of back pain. The participants were placed into two groups at random: The intervention group was offered a shoe lift to be placed inside the shoe to gradually decrease the difference in leg length, whereas the control group only received supporting insoles. The prevalence of back pain in these two groups was observed for 12 months. During the year, the participants responded to this same survey four times: at the beginning of the study and after 3, 6 and 12 months. Following the intervention, information about sick leaves and visits to the doctor was collected for two years. Leg length discrepancy was measured with a laser-based ultrasound method developed for the study, which is a non-invasive and fast method for reliably measuring lower limb discrepancy in standing position. Absences due to back pain were collected from the employer's register, and gender, age, BMI and the number of visits to the doctor were collected from the occupational health service provider's register. In the questionnaire, the respondents were asked about smoking and factors relating to the RAND-36 Measure of Health-Related Quality of Life, the Oswestry Disability Index (ODI), and the Roland Morris Disability Questionnaire (RDQ). They were also asked to evaluate their lower back and sciatica pain on the visual analogue scale (VAS). Outcome variables chosen for this study were the magnitude of lower back and sciatica pain (VAS), the length of sick leaves due to lower back pain (M50-54 in ICD-10), the number of visits to the doctor due to back pain, and a variety of factors relating to RAND-36, ODI and RDQ.

2019