The Hip-twist Jump: A Unique Mechanism for Jumping in Lungless Salamanders

Abstract

Abstract Many terrestrial and aquatic animals jump to escape predators. Most terrestrial animals use robust hindlimbs to produce the power needed to lift their bodies off the ground. This paper explores an alternative jump mechanism used by the lungless salamander, Desmognathus ochrophaeus. Previous work on this jump mechanism suggested that lungless salamanders invoke rapid torso flexion to hurl themselves into the air with minimal hindlimb contribution. The current study was designed to investigate how salamanders pushed off the ground to jump and to determine whether elastic structures contribute to jump power amplification. Specifically, we focused on trunk action, hip rotation, limb placement, and jump power production. We used high speed cameras to film salamander jumps and used these videos to conduct a subsequent motion analysis. Our results demonstrate that prior to jumping, the trunk flexes laterally into a C-shape while the hindlimb (inside of the bend) is planted in front of the hips. Next, th...