Mechanical properties of river otter limb bones

Abstract

AbstractThe determination of the bone strengths of wild animals has many potential advantages, which include the ability to estimate age of animals; monitor strengths of bones as influenced by contaminants, particularly lead; provide appropriate data for design of capture, handling, and holding equipment to minimize the possibility for bone fracture in captured animals; and measure effects of nutrition on bone strength. The objectives of of this study were to provide data on the mechanical properties of limb bones of river otters and to consider effects of age and sex on the properties.Three‐point bending and shear tests were conducted on the radius, ulna, tibia, and fibula. The three‐point bending tests were first conducted on the bones loaded within their elastic limit. These tests were used to evaluate the modulii of elasticity of the bones. The data on the modulii indicated that age and sex did not have significant effects on the values. The four different bones tested had approximately the same modulus of elasticity, with an average value of 14. 1 gigapascal (GPa).The shear tests were conducted on the limb bones to failure in order to determine the maximum breaking force and strength of the bones. The shear force of the radius tended to increase with age and there was a significant (P < .001) age effect. The shear force of the ulna for males was significantly (P < .002) higher than that of the females. A similar trend was observed for the fibula (P < .03). The shear strength of the radius increased with age and there was a significant (P < .005) age effect. There was also a significant (P < .001) effect of sex on shear strength of the radius; values for females were higher. There were no significant effects of sex or age found on shear strengths of the ulnae, tibia, and fibulae.