A prospective study of the dorsal spine was done in 337 workers chosen at random, in the aim of determining whether there was a clinical and radiological correlation, and the possible influence of the type and duration of work done on the appearance of the disorders. The series was composed of 265 men (19-63 years old) and 72 women (27-63 years old). Thirty-five per cent of the overall series complained of dorsal pain (53% in the women, 30% in the men). In one third of cases, the problems lead to work stoppage, and about 8% had to change jobs. Sixty-six per cent of the overall group showed some radiological change, without there being a significanct difference between the two clinical groups. Sixty-two point five per cent of the symptomatic group showed some radiological change. The presence of dysplasia, static changes and arthroses was observed in similar percentages in the symptomatic and asymptomatic groups. The exercise index has no relation with the symptoms since it was very similar in the two groups. The individuals with an above-average exercise index showed a higher incidence of arthrosis, but only in the group of men more than forty years old (this was statistically significant). As was to be expected, the incidence of arthrosis increases with age, without a difference between the two groups. Arthrosis was much more frequent in cases of major vertebral dysplasia (cuneiform or trapezoid vertebra), 56% of cases, than in those with minimal dysplasia (Schmorl's nodule, irregularities of the apexes), 24%, and in cases of dysplasia, 29%.