Final answer:
Scheuermann's kyphosis is identified by an excessive thoracic kyphosis angle, the presence of Schmorl's nodes, and vertebral wedging in three consecutive vertebrae.
Step-by-step explanation:
Scheuermann's kyphosis is a form of kyphosis that occurs due to a structural abnormality in the spine, typically seen in adolescents. Three diagnostic criteria for Scheuermann’s kyphosis include: 1) an angle of thoracic kyphosis greater than 45 degrees measured by Cobb's angle, 2) the presence of Schmorl's nodes or irregularities in the vertebral endplates, and 3) wedging of 5 degrees or more in three consecutive vertebrae. Kyphosis often originates from developmental anomalies, pathological changes, or obesity, which can accentuate the normal curves and result in abnormal excessive curvatures of the thoracic region. Disorders such as osteoporosis may weaken vertebrae, leading to an excessive posterior curvature that characterizes kyphosis.