Meeting Abstract

P3.57  Tuesday, Jan. 6  Correlations of bone strain, jump performance and limb kinematics in frogs and toads ESPINOZA, N.R.*; BLOB, R.W.; Clemson Univ.; Clemson Univ. nespino@clemson.edu

During locomotion, the magnitude and regime of loads on limb bones can be influenced by modifications of limb posture. In frogs, jumps of similar overall performance (e.g., take-off velocity) show variable magnitudes of limb bone strain. To test whether variations in limb kinematics might account for variation in bone loading during jumping in frogs, we collected high speed video of bullfrogs (Lithobates catesbeianus (Rana catesbeiana)) and cane toads (Chaunus (Bufo) marinus) during jumps in which we simultaneously recorded bone strains, and regressed strain magnitude values on several kinematic and performance variables. Despite a large range in strain magnitude in each species, few individuals showed correlations between magnitudes of peak longitudinal strain and values of performance and kinematic variables at the time of peak longitudinal strain (e.g., maximum velocity and acceleration, and angles of femur retraction, femur adduction, knee, ankle, tarsometatarsus, and metatarsophalangeal joints). This suggests that unlike many other species previously examined, variation in strain magnitude is not strongly influenced by limb position. Instead, strain magnitudes are commonly correlated with the rate of loading. (Supported by the NSF IOB – 0517340)