When the bone is broken, the muscles lose their natural support.
The ligaments or tendons (Holds ur Muscles on 2 ur bones) might have torn or stretched out causing ur muscle 2 become loose rather than being drawn tight, as it normally is.
Because the bone is the structure of the body. It would be like trying to run a car without an axel or wheels.
Muscles, bones and tendons work together to move your arm. The tendons will connect the muscles to the bones and the bones will provide the necessary support which will facilitate the movement.
Muscles change the relative position of the bones. The bones are just the passive (but required) part.
The bones do not move, neither do they work alone. In order to move the bones need help from the joints and muscles. The muscles pull on the joints therefore making the bones move.
Your muscles pull on bones but they never push bones.
The bones and muscles of the leg work together when the leg moves. The bones give the leg its structure, while the muscles hang onto the bones and allow the leg to actually move. The muscles make their movements via contractions and expansions.
The Muscles are attached to the bone through Tendon. All the body movement from the brain goes to the muscles and muscle in turn transmit to the bones.
Muscles do is to command the bones to move and you need food and energy to move around.
Because the muscles work by pulling on the bone. If the bone is broken, the force may not be transmitted to where it is needed.