SENSITIVITY OF FEMORAL STRAIN PATTERN ANALYSES TO RESULTANT AND MUSCLE FORCES AT THE HIP-JOINT

An automated geometrical preprocessor was developed with the aim of cr eating three-dimensional finite element models (FEM) of the human femu r. On the basis of postprocessed computed tomography data, this prepro cessor makes possible rapid flexible and regular meshing with 'brick' elements. Three different material properties were modelled at the pre sent stage of development. Sensitivity analyses demonstrated that the strain energy density (SED) patterns of the different femoral pars's w ere most sensitive to the implementation of an iliotibial tract force. The variation of the resultant hip force and abductor force direction within the sagittal plane demonstrated a SED minimum at an anterior i nclination of 13 degrees; the variation of the resultant force directi on within the frontal plane demonstrated a minimum SED at a medial inc lination of 21 degrees relative to the mechanical axis of the lower li mb. The orientation of the connecting line between the surface-SED-pea ks in the horizontal view was Sound to De most sensitive to the variat ion of the resultant force within the sagittal plane.