"If you move something 10 pounds through space and then stop suddenly, there's a little overshoot. When you transfer weight from one leg to another, there's a certain way that it happens"

This quote by Brad Bird is describing the idea of inertia. Inertia is the propensity of an object to stay in its current state of movement. In this quote, Bird is suggesting that when an object is relocated, it will continue to relocate till it is quit. This is due to the momentum that is produced when the things is relocated. He is also recommending that when moving weight from one leg to another, there is a certain way that it must be performed in order to stay clear of overshooting. This is due to the fact that the momentum produced by the transfer of weight can trigger the body to relocate better than meant. Bird's quote is a tip that inertia is a powerful pressure and needs to be thought about when making movements.