This paper presents some of the results of a research project entitled "Dynamic Response of the Human Leg to Impact Loading". A test facility was developed for laboratory experimentation that stimulates leg impacts during automobile, pedestrian, motorcycle, and bicycle accidents. Analyses and discussions are presented for several experiments designed to study the mechanical behaviour of the human femur subjected to impact loading. About one hundred bones have been broken in the specially designed laboratory as part of this research. The testing was divided into four categories: (1) femurs subjected to bending loads; (2) femurs under torsional loads; (3) femurs under axial loads, and (4) fresh tissue impact loadings. The femur appears stronger when impacted in the anterior-to-posterior (a-p) direction than when impacted in the lateral-to-medial (l-m) direction. The fractures produced by the a-p impacts provide interesting clinical information. It was found that even very small torsional preloads can greatly diminish the femurs breaking strength. Axially loading the femur allowed mapping of the stress along the femur to accurately predict fracture locations. Femur and intact thigh tests are continuing, and these results will be supplemented in the future. This paper presents the implications of the first designed series of tests. (A)
Abstract