Meeting Abstract
Lateral undulation and trunk flexibility which offer performance benefits to maneuverability and stability are important characteristics of sprawling postured tetrapod locomotion except for turtles. Despite their bony carapace preventing lateral undulations, turtles have been able to improve their locomotor performance by increasing stride length via greater limb protraction. Would a generalized sprawling tetrapod respond with the same kinematic changes if lateral undulations were limited? The goal of this study was to determine the role of the lateral movement of the vertebrae in tiger salamanders (Ambystoma tigrinum) by reducing the role of vertebral flexibility. This was done by artificially limiting trunk flexibility by attaching a 2-piece “shell” around the body between the pectoral and pelvic girdles. Adult tiger salamanders (n =3, SVL = 9 cm-14.5 cm) walked on a 1 m trackway under three different conditions: no shell, flexible shell (tygon tubing), and rigid shell (PVC tubing). Trials were filmed in a single, dorsal view using a Kodak Playsport camera (30 fps). Kinematic markers on the fore and hindlimbs were digitized using DLTdataviewer5. Protraction and retraction angle calculations and statistical analyses were performed in R. We thus predict that increased range of limb movement may be a compensatory mechanism available to a wide range of tetrapods challenged with reduced lateral undulation.
