Meeting Abstract

P1.94  Thursday, Jan. 3  Mechanical Properties of Frog Hindlimb Bones PRUETTE, M.E.*; ESPINOZA, N.R.; BLOB, R.W.; Duke University; Erskine College; Clemson University megan.pruette@duke.edu

Compared to most other vertebrates, frogs use a novel style of locomotion that, in most frog species, consists of sporadic high-energy jumps powered by the hindlimbs. Frog hindlimb bones must be able to withstand the potentially erratic loads associated with this saltatory mode of locomotion. To evaluate the load bearing capacity of frog limb bones, we measured the mechanical properties of the femur and tibiofibula in three-point bending and torsion from adult individuals of representative species that grow to large adult size, including the bullfrog Rana catesbeiana. Strain gauges were attached to whole bone specimens, and forces, displacements, and strains were recorded continuously through the points of yield and fracture. Stresses and strains at both yield and fracture are in the range of higher values reported for vertebrate limb bones. Moreover, bullfrog hindlimb bones also have very high values of stiffness, which would facilitate efficient transmission of the high muscular forces they exert during strong jumps. Thus, the mechanical properties of bullfrog hindlimb bones not only provide protection from damage that could result from loading during jumping, but may also be specialized to maximize muscular force transmission. Supported by NSF I0B-0517340.