Radiographically detectable degenerative changes of the lumbar spine among concrete reinforcement workers and house painters.

In this study of lumbar degeneration and the role of mechanical loading in its development, lateral lumbar radiographs of 216 concrete reinforcement workers and 201 house painters aged 25-54 years were examined. Disc space narrowing occurred at about 10 years and spondylophytes at about 5 years younger age in the former than in the latter group. Risk ratios (RR) were estimated from the regression coefficients of logistic regression models. RR for the univariate effect of occupation on disc space narrowing was 1.8, and adjustment for age, earlier back accidents, height, body mass index and smoking had only a minor effect on this relationship, adjusted RR 1.8. The crude RR for spondylophytes was 1.5, and the adjusted RR 1.6. Earlier back accidents showed a significant univariate relationship with DSN, but in multivariate analysis this variate did not retain its significance. It was concluded that heavy physical work enhances the degenerative process of the lumbar spine. Materials handling and postural loading are proposed to be occupational factors of importance in the development of both disc space narrowing and spondylophytes.