Internal rotation refers to:

• A. Rotating toward the midline
• B. Rotating away from the midline
• C. Bending the joint
• D. Extending the joint

Answer: (D)

Internal rotation refers to turning a limb toward the midline of the body around the joint’s axis. For the shoulder or hip, this means rotating the arm or leg so the front surfaces move inward toward the body's center. Rotating away from the midline is external rotation. Bending the joint is flexion, while extending the joint is extension. So internal rotation is defined by the direction of rotation toward the midline, not by bending or straightening the joint.