Meeting Abstract
Scale and temperature are two fundamental variables that affect organismal function, including performance of musculoskeletal systems. Many small animals use elastic recoil to effectively amplify muscle power to achieve high-performance movements with power demands exceeding muscle capabilities. In larger animals elastic recoil should be less important as their muscles are better able to directly meet high power demands. Elastic recoil also reduces effects of temperature on performance. Muscle power decreases with decreasing temperature, but power amplification in elastic recoil is not affected by temperature. If the use of elastic recoil is dependent on scale, then scale and temperature will interact to influence performance. If larger animals use less elastic recoil to achieve high performance, they will also be more susceptible to changes in temperature. Alternatively, elastic recoil may be used regardless of scale because of the thermal robustness it confers. To investigate these interactions, we measured scale and temperature effects on muscle properties from Cuban tree frogs and used these data to predict jump performance. We compared predictions to values of jump performance from frogs ranging in body mass from 1-30g at 10, 20, and 30°C. Jump performance decreased significantly with decreasing temperature and larger frogs had significantly higher jump performance than smaller frogs, but temperature effects were similar for all frogs regardless of body mass. Comparisons to predicted values suggest that elastic recoil contributes similar proportions of energy to jumps in all frogs. Analyzing joint movements would allow us to determine if kinematics and kinetics of elastically powered ankle extension and muscle-powered knee and hip extension are similarly affected by temperature at all scales.
