MAGNETIC-RESONANCE-IMAGING FINDINGS OF LUMBAR SPINE IN THE YOUNG - CORRELATION WITH LEISURE-TIME PHYSICAL-ACTIVITY, SPINAL MOBILITY, AND TRUNK MUSCLE STRENGTH IN 15-YEAR-OLD PUPILS WITH OR WITHOUT LOW-BACK-PAIN

From a population of 1,503 schoolchildren, 38 15-year-old children rep orting recurrent or continuous low-back pain and 38 asymptomatic contr ols (34 boys and 42 girls) matched for age. sex, and school class were selected for tests of spinal mobility and trunk muscle strength, and for a magnetic resonance imaging (MRI) study of the lumbar spine. In a ddition, the subjects were asked about leisure time physical activitie s in an interview preceding the measurements. Spinal muscular atrophy was the only finding that was more common among physically inactive su bjects (p = 0.005). Moreover, increased occurrence of disk degeneratio n (DD) was observed in the low-activity group. However, the difference was not significant. Neither Scheuermann-type changes nor DD were rel ated to spinal mobility or trunk muscle strength. Children with disk p rotrusion were, on the average, taller (p = 0.044), and their lumbar f lexion measured by flexicurve was decreased (p = 0.043). Our results s trengthen further the evidence that MRI is a sensitive measure and tha t imaging findings must be interpreted carefully with respect to pain and physical impairment of the lumbar spine. Furthermore, no clear evi dence of the association between physical activity and early DD could be found.