Substrate Stiffness Affects the Coordinated Landing of Rhinella marina


Meeting Abstract

105-2  Sunday, Jan. 6 13:45 – 14:00  Substrate Stiffness Affects the Coordinated Landing of Rhinella marina DUMAN, AJ*; AZIZI, E; Univ. of California, Irvine; Univ. of California, Irvine aduman@uci.edu

The musculoskeletal system is responsible for safely dissipating energy associated with locomotion. Rapid decelerations of the body and dissipation of mechanical energy are common across modes of terrestrial locomotion including running downhill and landing from a jump. The variation in mechanical properties of the environment can change the rate and magnitude of energy that needs to be dissipated by the musculoskeletal system and may require changes to strategies used to minimize the risk of injury. In particular, the compliance of a substrate may be used to temporarily store energy to reduce the energy imparted on the body upon impact. The well-documented, coordinated landing of Rhinella marina offers a unique model to determine how substrate stiffness may influence their landing behavior. Using force-plate ergometry and high-speed videography we compare the landing performance of R. marina (n = 5) across four compliance treatments relative to body weight (BW); 0, 2.5, 5 and 10 mm BW-1. Landing performance was characterized by finding the energy dissipated by the forelimbs normalized to the total energy of the system. Inverse Dynamics were also employed to compare the relative energy contributions of forelimb joints as well as how they differ with substrate stiffness. Our results imply that substrate stiffness increases the relative amount of energy dissipated by the forelimbs to decelerate the body.

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