The ranges of spinal movement in 390 healthy children aged from 10 to 15 years have been recorded. These measurements are in two planes, anterior and lateral; they are quick and easy to perform and require no special equipment, just a tape measure. Many conditions occurring in childhood can lead to limitation of spinal movement: these include juvenile ankylosing spondylitis, spondylolisthesis, Scheuermann's vertebral osteochondritis, discitis and vertebral fractures, the latter being not uncommon in children receiving prolonged corticosteroid therapy. The purpose of the present paper is to define the normal range for anterior and lateral spinal flexion in adolescents and to correlate these with sex, age, height and weight.