Meeting Abstract

43.6  Saturday, Jan. 5  Linking leg morphology, gait, whole-body and individual limb mechanics in terrestrial locomotion MCELROY, Eric J*; REILLY, Stephen M; Ohio University; Ohio University em386403@ohiou.edu

Terrestrial locomotion occurs when the musculoskeletal system moves the legs producing coordinated footfall patterns (gaits), which output forces to the substrate resulting in center of mass movement (mechanics). While the links among these components have been studied in a handful of bipeds and large quadrupeds they remain poorly understood in other groups. To address this problem we quantified locomotor morphology, gait, and mechanics during running in a sample of 10 lizard species. Radiographs of museum specimens were used to measure the lengths of 16 skeletal elements related to locomotion. Then 3 � 5 individuals of each species were filmed over their entire range of running speeds while moving down a 3-meter racetrack with an incorporated force platform. We measured stride length, step length, float distance, and stride frequency from high speed video and the impulse, magnitude and relative timing for forces in the vertical, fore-aft, and medio-lateral directions. These variables were quantified for the forelimbs only, the hindlimbs only, and for whole-body force records. We constructed matrices for size-corrected morphology, size and speed corrected gait variables, and size and speed corrected force variables. Then we used Mantel statistics to test for multivariate association between morphology, gait, and force. In cases where there was a significant relationship between these variables we generated correlation matrices to discover which variables were driving multivariate significance. Results are discussed in the context of both functional interrelationships and co evolutionary patterns in morphology, gait, and mechanics.