Osmosis and diffusion are both examples of passive transport, neither of which requires energy to cross the cell membrane from areas of high concentration to areas of low concentration. Active transport is the process of moving molecules and ions from areas of low concentration to areas of high concentration. Active transport requires energy in the form of ATP.
The muscle pulling on a bone often works like a type of simple machine called a lever. Most of the bones of the limbs (arms & legs) act as levers for the body. I hope that this is the answer that you were looking for and it has helped you.