TY - JOUR
T1 - The Hip-twist Jump
T2 - A Unique Mechanism for Jumping in Lungless Salamanders
AU - Hessel, Anthony L.
AU - Nishikawa, Kiisa C.
N1 - Publisher Copyright:
Copyright © 2017 Society for the Study of Amphibians and Reptiles.
PY - 2017/12/1
Y1 - 2017/12/1
N2 - 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, the salamander rapidly undulates, rotating the pelvic girdle toward the planted hindfoot. At this point, the planted hindlimb acts like a strut that allows the salamander to pole-vault over the planted hindfoot and into the air. We estimate that the trunk axial muscles are the main contributors to jump power, but they must be aided by elastic structures that amplify jump power output. Future studies should focus on identifying the elastic structures responsible for power amplification as well as possible neurological connections between the salamander jump and the C-start escape strategy of fishes.
AB - 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, the salamander rapidly undulates, rotating the pelvic girdle toward the planted hindfoot. At this point, the planted hindlimb acts like a strut that allows the salamander to pole-vault over the planted hindfoot and into the air. We estimate that the trunk axial muscles are the main contributors to jump power, but they must be aided by elastic structures that amplify jump power output. Future studies should focus on identifying the elastic structures responsible for power amplification as well as possible neurological connections between the salamander jump and the C-start escape strategy of fishes.
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U2 - 10.1670/16-112
DO - 10.1670/16-112
M3 - Article
AN - SCOPUS:85028771579
SN - 0022-1511
VL - 51
SP - 461
EP - 467
JO - Journal of Herpetology
JF - Journal of Herpetology
IS - 4
ER -