Hello, I have been assigned a project to find a device to improve on, and one of the tasks is to create a force body diagram. I have a little bit of confusion when it comes to drawing it because if I'm writing the paper on shoes, and how it improves the movement of the feet, how will the free body diagram look? I understand that in able for your whole body to move, you have to consider the frictional force, applied force, and the normal force. Does that include the forces exerted from the ground? Also if you were to focus the force body diagram primarily on the feet, what would the forces be applied when you are walking/running? Would the forces change depending on the structure of the shoe that is being worn? How would you get the magnitudes of the forces? Please help!