How do bones and joints affect physical performance?

lets say you break a leg. you cant put any weight on the leg because the bone is broke. IF you wanted to run, you couldn't because you could cause further damage to the broken bone and would cause extreme pain. So, you wouldn't get too far. If you were having stiff joints, you couldn't move as fast as you would like because your joints are tight making it difficult for your body to move quickly or normally.