Extended Data Fig. 1: Work multiplication in more detail.

a, Similar to a ratcheted motor in Fig. 1, a rotary motor can accomplish work multiplication through multiple rotations instead of multiple strokes. b, The output work of a biological jumper is determined by fixed parameters (motor stroke, leg stroke and motor force), but work multiplication overcomes this for engineered jumpers: For biological jumpers, motor stroke and leg stroke determine an effective gear ratio, if the entire stroke of both is to be used (in animals, the gear ratio varies around this value slightly throughout the jump)¹⁹. With this determined gear ratio and a fixed motor force (assuming a size of motor), the leg force is determined. Finally, with the fixed leg stroke and determined leg force, the output work is determined. By contrast, for engineered jumpers, although the leg stroke is roughly fixed (assuming a size of jumper), the motor can make multiple strokes or rotations, allowing the gear ratio to be designed (higher gear ratio will result in more strokes, at the cost of more time). With this designed gear ratio and a fixed motor force (assuming a size of motor), the leg force is also multiplied with respect to the leg force in the single-stroke case. Finally, with the fixed leg stroke and the multiplied leg force, the output work is also multiplied.