In this anatomy lesson, I’m going to demonstrate rotation, which is a body movement term that describes a bone moving around a central axis.
Rotation Body Movement Term in Anatomy
When I think of the rotation body movement, I like to picture a screw turning to either the right or left, as that is similar to the rotation movement that can occur in the body.
Rotation can occur at the head/neck, vertebral column, and the ball-and-socket joints of the upper and lower limbs (shoulder joint and hip joint). Let’s take a look at these movements, starting with the head.
Head and Neck Rotation
The head can rotate laterally to either the left or right, thanks to the pivot joint between vertebrae C1 (atlas) and C2 (axis). Moving the head back toward the anatomical position is medial rotation of the head.
Trunk Rotation
The vertebral column can also rotate laterally to either the left or right. Returning the trunk back toward the anatomical position is medial rotation of the trunk.
Arm Rotation (Medial and Lateral)
The ball-and-socket joint of the shoulder allows the humerus of the arm to rotate laterally, or away from the body’s midline, which is also called external rotation. It can also rotate medially, or toward the body’s midline, which is also called internal rotation.
Thigh/Leg Rotation (Medial and Lateral)
The ball-and-socket joint of the hip allows rotation of the thigh’s femur. Like the humerus, it can rotate laterally, or away from the body’s midline, which is also called external rotation. It can also rotate medially, or toward the body’s midline, creating an internal rotation movement.
Tip for Medial vs Lateral Limb Rotation
Be sure to focus on the anterior surface of the femur or humerus when you do this movement, because that’s the focal point for determining medial vs lateral rotation.
Free Quiz and More Anatomy Videos
Take a free rotation quiz to test your knowledge, or review our quick rotation video. In addition, you might want to watch our anatomy and physiology lectures on YouTube, or check our anatomy and physiology notes.