Meeting Abstract

P1.169  Monday, Jan. 4  Functional morphology of acceleration in the phyrnosomatine lizard, Sceloporus woodi MCELROY, Eric J*; BAUR , Anna ; MCBRAYER, Lance D; College of Charleston; College of Charleston; Georgia Southern University

Studies of locomotor performance have historically focused on maximum sprinting speed and its morphological and functional correlates. However, there has been far less focus on how animals reach their maximum speed (i.e. acceleration capacity). Likewise, it remains unclear how acceleration and speed are inter-related and which functional and anatomical traits underpin these aspects of burst locomotion. To address these issues, we quantified maximum sprint speed and acceleration in twenty individuals of the ground-dwelling phrynosomatine, Sceloporus woodi , as they accelerated from a standstill to maximum speed. To elucidate the possible functional correlates that may mediate the relationship between speed and acceleration, we measured 3D ground reaction forces and limb and axial kinematics for each trial. Additionally, we sacrificed a subset of individuals to measure aspects of musculoskeletal anatomy (muscle mass, fiber length, PCSA, in and out lever lengths, and bone lengths) relevant to these performance traits. Results show a positive correlation between maximum speed and acceleration in agreement with previous studies of small lizards. However, considerable variation also exists in these data, suggesting that some individuals may achieve similar maximal speeds via different functional mechanisms than other individuals.