How bones attach to each other and to muscles and how this aids movement

Tendons connect the bones.

Explanation:

The muscles are connected to bones through tendons, and this way the contraction of the muscle helps the movement of the bones through them.

The muscles work in pairs and in this way they move. While one muscle is contracting, the other one relaxes.

The muscles work in a form of contraction-relaxing. The flexor contracts to bend a limb at a joint.