This muscle is activated by a giant fiber which runs from the
brain to the thorax. The first figure, shows a video of the leg moving
when the giant fiber is stimulated electrically.
Video: Normal speed
Slowed down 10 times
To measure the force used to make the fly jump we built a force
platform from a small strain gauge, and made the fly kick down onto
this by attaching a glass needle between fly and force platform
Fly clamped and fixed to needle
The measurements show the fly generates a peak force abou 20 times its
own weight, so that it can jump upwards easily. The force calculated from the jumping distances matches well with that measured in our apparatus.