On the mathematical analysis of stress in the human femur

A mathematical model for the behavior of the human femur is used to examine the effect of muscle forces on the resulting stresses and strain energy during a one-legged stance. The results show that tension in the tensor faciae latae can very effectively serve to counteract bending stresses in the femur while also reducing the strain energy. It was found that the choice of mathematical model to represent the behavior of the femur is important. Stresses in the femur are calculated using both beam theory and a continuum theory in the form of a finite element computer program. The analyses include joint and muscle loadings. The results of the study show that beam theory is appropriate for the calculation of stresses in the shaft of the femur, but gives an inaccurate picture of the stress distribution in the regions of the greater trochanter and the femoral head as well as the areas of muscle attachment. In these regions a continuum theory is required.