Thoracic kyphosis and lumbar lordosis during the growth period in children.

The thoracic kyphosis and the lumbar lordosis were studied in 1,101 healthy children in consecutive age-groups between 8 and 16 years of age. The sagittal curves were estimated with a spinal pantograph--a noninvasive device--with the child standing in a relaxed position. The accuracy and the reproducibility of this technique are studied and shown to be acceptable. The thoracic kyphosis varied in both boys and girls. The least pronounced kyphosis was seen at the age of 10-12 years. At the age of 8 and 14-16 the mean range of the kyphosis increased statistically significantly. A positive correlation was also seen between the velocity of growth and the range of the kyphosis. In the lordosis, a similar trend could not be seen, but instead a slow continuous increase. A positive correlation was also observed between the ranges of the kyphosis and lordosis in most of the age-groups. An individual variation was, however, seen and wide ranges of kyphosis as well as lordosis must be accepted as normal variations.