UC Riverside

In order to understand the evolution of locomotion, lizards are often used to study the relationships between morphology and locomotor performance. However, the mechanisms by which himblimb morphology results in jumping performance are not well understood, despite the fact that jumping may be important for fitness in many lizard species.

Here I investigate the ways in which mechanical power is generated by the hindlimbs of jumping collared lizards, Crotaphytus collaris. I examine the contribution of each hindlimb joint to total power output. I also test the hypothesis that these lizards utilize elastic power amplification.

I found a high degree of individual variation in the relationships between joint kinematics and jump power, suggesting multiple strategies for controlling jump performance and highlighting the importance for considering individual variation in biomechanical studies. I also found peak power outputs exceeding the physiological limits of lizard muscle suggesting the presence of a power amplification mechanism. Additionally, the use of countermovements may enhance jump power, though possibly through mechanisms other than elastic energy storage.