Cartilage layers in the articulations between the solid geometry were modelled by manually identifying the articulating surfaces between bones (Fig. 4.3). To form the cartilage, extracted profiles representing the surfaces of the cartilage distribution were extruded with a thickness size half of the minimum distance between two bones [5], resulted in a good geometrical representation and material distribution of the cartilage (Fig. 4.4). In total, there were 35 cartilages constructed. The distribution of the cartilage was compared and considered acceptable according to an anatomy software [2].

All 60 ligamentous constraints as shown in Fig. 4.5 were modelled using linear link elements [6], and the positions of their insertion points were estimated based on previously published anatomical studies [2, 4]. The stiffness of the ligaments varied widely between 40 and 350 N/mm as were reported in previous experimental works (Table 4.1) [5, 7–10]. For ligaments that did not have published material parameters, it was assumed that the properties of the neighbouring ligaments would apply [11]. To simulate distribution of the origin and insertion of the ligaments, parallel multiple links were applied [4, 11].