An elastostatic, finite element model (designated THORAX I) of the human thoracic skeleton has been developed. The model includes the primary load-carrying members of the thorax;​ namely, the sternum, costal cartilage, ribs, and vertebral column. The soft tissue has been neglected.

Using gross geometric data measured from a skeleton with an apparent ‘small’ frame and approximate cross-sectional properties, the THORAX I model has been subjected to three loading distribution applied to the anterior chest wall in the anterior-posterior direction. Calculations were carried out on the IBM 7094 computer, and primary attention was focused upon the displacement fields of the sternum, costal cartilage and ribs and stresses in costal cartilage and ribs. The sternum and rib nodal point displacement fields are reported in detail, and a simple 2-degree-of-freedom model for the sternum, which correlates well with the analytic results, is also presented. Maximum normal stresses in the cartilage and bony regions of the individual ribs for one loading condition are also given.