King type I:
A S-shaped curve in which both the thoracic and lumbar curves cross the midline. The magnitude of the Cobb angle of the lumbar curve is larger than that of the thoracic curve on standing roentgenogram. Both curves are structural, with nearly equal flexibility.
King type III:
A thoracic curve in which the lumbar curve does not cross the midline (so-called overhang).
King type V:
A double thoracic curve with T1 tilted into concavity of upper curve. The upper curve is structural on side bending.
Table 2.3 King type I through King type V (King et al., 1983).