Figure 2

Loading conditions and zoning of the disc. (a) Loading conditions of the disc, obtained by the displacement of corresponding nodes on the boundary of disc in the reference state (6 mm opening; grey outline) and the disc in the current states at varying distances of opening (7–24 mm; white outline). (b) Diagram showing the fifteen zones analyzed in this study, comprising posterior (P), medial-posterior (M-P), medial (M), medial-anterior (M-A) and anterior (A) positions in each of the superior (S), middle (M) and inferior (I) layers. The central line represents the path used to evaluate the stretch of the disc.