It is attached to both the bones by strong cords called tendons. When the muscles contracts, usually just one bone moves. For example when the biceps in the arm contracts, the radius moves but the scapula does not. When a muscle contracts, usually just one bone moves. The other is stationary. The origin is where the muscle joins the stationary bone. The insertion is where it joins the moving bone. When a muscle contracts, the insertion moves towards the origin. Tendons are the cords and straps that connect muscles to bones. At the bone, the fibres of the tendon are embedded in the periosteum of the bone.