[Biomechanical stress analysis of the lower extremity]

Within the field of prevention and rehabilitation, a detailed knowledge of the internal stresses and strains, for example the forces acting on and within joints, muscular force, is desirable or indispensable. The complex analysis of movements described here is based on a biomechanical model that takes into account the results of research done by F. Pauwels showing that muscular activity helps reduce the loading of tubular bones. The principle of functional adaptation provides a reasonable explanation for the "muscular redundence" of the locomotory system, and forms the basis for the calculation of internal loads. The results of the analysis include muscular and joint forces and the stresses within femur and tibia. The required anatomical data were for the most part obtainable directly from the test subject by magnetic resonance imaging. The calculated muscular forces are in good agreement with EMG measurements.