Finite Element Modelling of the Healthy Wrist Joint - Computational Biomechanics of the Wrist Joint - page 39

Fig. 4.5 Finite element
model of the healthy wrist.
The ligaments can be seen as
sets of links connecting bones
4.2 Modelling of Cartilages
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 distri-
bution were extruded with a thickness size half of the minimum distance between
two bones [ 5 ], resulted in a good geometrical representation and material distri-
bution 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 ].
4.3 Modelling of Ligaments
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 experi-
mental 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