Meeting Abstract
Muscles generate the force needed for locomotion, which is crucial for an animal’s ability to perform fitness-relevant tasks in a heterogeneous environment. In whole-organism performance, such as terrestrial walking or sprinting, different tasks require multiple muscles to be activated in patterns constituted by varying intensities and times. Direct relationships, redundancy and multitasking are inherent parts of muscle function. Direct relationships and redundancy occur when different muscles have specific roles, yet often work together to accomplish tasks and allow for movement. Multitasking happens when a single muscle contributes to multiple tasks. This multi-functionality of muscles and variation in activation pattern allow for the successful completion of a wide range of locomotor tasks with a single set of muscles in different ecological contexts. Terrestrial and aquatic locomotion can place different muscular demands on an animal. Aquatic locomotion often involves predominantly sinusoidal oscillations of the body to propel the animal horizontally through the water while terrestrial involves limb movements to carry the body over the substrate with lateral undulation playing a smaller role. Because the morphological properties of muscle do not change as an animal switches locomotor tasks, an important question is how does the function of a set of locomotor muscles differ between locomotor modes such as running, jumping, climbing, and swimming? We address this by looking at differences in in vivo motor patterns of the mm. caudofemoralis longus, pubioischiotibialis, gastrocnemius major, and tibialis longus in the hindlimbs of Basiliscus vittatus lizards while performing these modes of locomotion. We show that activation patterns vary during running, jumping, climbing, and swimming.
