BUILT FOR JUMPING - THE DESIGN OF THE FROG MUSCULAR SYSTEM

Frogs must generate a high level of mechanical power when they jump. T he muscular system of frogs that jump is presumably designed to delive r these high powers. The length changes and activation pattern that mu scles undergo during jumping were measured, and isolated muscle bundle s were driven through this in vivo pattern. During jumping muscles gen erated maximum power. Specifically the muscle fibers (i) operated at o ptimal sarcomere lengths, (ii) operated at optimal shortening velociti es, and (iii) were maximally activated during power generation. Thus, many different parameters must have evolved in concert to produce a sy stem capable of this explosive jumping movement.