Trunk asymmetries in a Belgian school population.

Two hundred seventy schoolchildren attending Belgian town schools were screened for trunk asymmetries. The present investigation confirms a wide prevalence of clinically evident asymmetries of the trunk. In the large majority of cases, the asymmetries were accompanied by a measurable rib hump and/or lumbar prominence, which have to be considered in scoliosis screenings. Age and sex do not have a clinically demonstrable influence on the degree and laterality of asymmetry in the school population examined. A height discrepancy of shoulders, scapulae, and iliac crests not exceeding 1 cm and a discrepancy in the depth of the waist triangles not exceeding 1.5 cm are so frequency that they must be considered as physiologic. The same applies to the rib hump (not exceeding 8 mm) and the lumbar prominence (not exceeding 5 mm). As in idiopathic scoliosis, the rib hump is predominantly situated on the right, especially in girls in the prepubertal period.