From a review of normal spines and spines afflicted with wedging round-back deformity in the thoracic region, it appears that persistence of the anterior vascular groove in the bodies of the thoracic vertebrae may play a role in the production of deformity by inviting anterior collapse of the vertebrae. Actual round-back deformity is the result of wedging of the vertebrae below the region of the fifth, sixth, and seventh thoracic vertebrae. This wedging accentuates the kyphos which normally is present at the fifth, sixth, and seventh thoracic vertebrae. It is believed that there is sufficient evidence to warrant treatment of children in the eight to fourteen year old age group who show this sign by x-ray and who present early clinical evidence of poor posture with round-back and increased lumbar lordosis.