There are more than 600 muscles that move together to move your body! ---Bones form the structure for our body, while muscles are responsible for pulling the joints, allowing us to move. The cartilage, muscles, ligaments, and tendons, all working as one holding bones together and letting joints move.
Sports agents can charge for their services in a variety of ways including: Percentage - Agent takes a percentage of a contract, typically 3-5%. Time - Agent, typically an attorney, charges an hourly rate, typically $400/hour.
In Football Manager, player agents can negotiate such a cut, called the sell-on fee percentage. If a player has such a clause in his contract, he gets that percentage of the fee when the club sells him. This game is uber realistic, so I think the same answer is correct in real life.