Three-Dimensional Biomechanical Analysis of the Bovine Humerus

Abstract

There are few reports on the biomechanical analysis of the animal humerus. In this study, a three-dimensional finite element model of the bovine humerus was created, and loaded with the physiological forces acting when the cow is falling or jumping (weight and impact forces). Subsequently the corresponding stress and strain distribution in the humerus for different inclined positions of bone was determined.The highest stress concentration occurred in the distal humeral diaphysis, both when only the reaction and load transfer forces were considered and when muscle forces were included too, although when muscle forces were included these maximum stresses decreased. In the distal humeral diaphysis, an increase was also observed in the cortical thickness; this may be a bone adaptation to reduce the maximum stresses. By understanding these bone adaptation processes at regional level, non-pharmacological treatments to some bone pathologies could be developed, mainly the ones characterized by loss of bone mass.Furthermore, taking into account both the humerus fracture strength and the maximum force that muscles can make without breaking, it is deduced that during jumping or falling the cow must maintain the humerus as vertical as possible to better bear the impact. This is in congruity with what was observed.The interest of this study is in improving the knowledge of animal humerus biomechanics and its application in orthopaedic design and surgical treatments.