What attaches to the bone and muscle?

Tendon

A tendon is a tough, fibrous cord of connective tissue that attaches a muscle to a bone. Tendons are made up of collagen fibers, which are very strong and flexible. They allow muscles to exert force on bones, which produces movement.

Tendons are also important for proprioception, which is the sense of the body's position in space. When a muscle is contracted, the tendon pulls on the bone, which sends a signal to the brain about the muscle's position.