Fig. 19

This figure shows the clinical picture and schema of blocks for the so-called non 3-non 4 curve pattern. This is called C type in Rigo classification. The trunk is also here divided into three blocks, like in A type, but there is a minimum translation and rotation of the main thoracic block against the two compensatory lower and upper bocks, which are both well-balanced on the polygon of sustentation. The main thoracic block is collapsed on the concavity and expanded on the convexity. The lower block can be also mildly collapsed on the concavity when there is a structural lumbar curve. The description on the figure is about thoracic curve convex to the side and is called “Right N3–N4 or C type.” The mirror case exists and it is called “left N3–N4 or C type”