- Rotator Muscle: The muscle that rotates any part of the body around or right-left is called rotator muscle. Rotation is the process of turning a part of the rotator cuff around or left and right. For example, the pronator muscle causes lateral rotation and the supinator muscle causes lateral rotation. The piriformis muscle helps rotate the femur.
- Protractor Muscle: A muscle that extends a body part forward is called a protractor muscle.