Modelling the abdominal wall response under active muscles and effective internal pressures.

Abdominal wall biomechanics is dependent on muscular con-traction and Intra-Abdominal Pressure (IAP) which character-ize different physiological functions and daily tasks. The active behaviour of muscular fibres must be considered within compu-tational models of the abdominal wall. A three dimensional Fi-nite Element (FE) model of a healthy abdomen is developed by implementing different constitutive models to describe the me-chanical behaviour of the different structures. Fascial tissues, aponeuroses and linea alba are modelled as hyperelastic fiber-reinforced materials, while a three-element Hill’s model is as-sumed for the muscles. IAPs are simulated by adopting an in-ternal abdominal cavity. The deformation resulting from different levels of muscle ac-tivation, corresponding to different tasks has been evaluated and the results corresponding to an abdominal crunch are shown. This model represents an advanced approach to simulate abdominal wall mechanics by considering active muscles and effective internal pressures in healthy conditions. The model described in this study can be hence used for a valid clinical support. By means of a similar numerical approach, abdominal pathologies can be properly investigated, such as potential her-niated regions.