Final answer:
The leading leg moves forward and creates torque, while the trailing leg moves backward to counterbalance the leading leg's motion.
Step-by-step explanation:
In an inverted pendulum, the leading leg is the leg that is ahead of the direction of motion, while the trailing leg is the leg that is behind the direction of motion.
When the inverted pendulum is in motion, the leading leg moves forward, creating a torque that helps to maintain balance and prevent the pendulum from falling over. The trailing leg moves backward to counterbalance the forward motion of the leading leg.
This coordinated movement of the leading and trailing legs helps to stabilize the inverted pendulum and keep it upright.