What Is the Difference Between Internal Rotation Exercise & External Rotation Exercise?

Two of the actions that your shoulder and hip joint are capable of performing are internal and external rotation. The difference between these motions is the direction of joint rotation. During internal rotation, your joints are rotating your bones toward the center of your body. During external rotation, the motion produced is away from your center.

  1. Shoulder Internal Rotation

    • The muscles responsible for rotating your shoulder joint inward toward your center are the subscapularis, anterior deltoid, pectoralis major and latissimus dorsi. The subscapularis, which is the frontal rotator cuff muscle, acts as the main mover during this motion. The other three muscles work to assist the subscapularis in pulling your humerus, or upper arm bone, in an inward direction. To do an internal shoulder rotation exercise, sit or stand with your right side facing a cable pulley machine. Grip the cable handle with your right hand, bend your right arm to 90 degrees and then pull the handle toward the center of your body.

    Shoulder External Rotation

    • The other rotatory movement of your shoulders, external rotation, is performed by the infraspinatus, teres major, teres minor and posterior deltoid muscles. These muscles all pull on the back of your humerus, thus bringing it away from your midline and toward the rear. To perform external shoulder rotation, sit or stand with your left side facing a cable pulley machine. Grip the cable handle with your right hand, bend your left arm to 90 degrees and then pull the handle away from the center of your body.

    Hip Internal Rotation

    • Your hips also function as internal and external rotators. Among your internal hip rotator muscles are the gluteus maximus, gluteus medius, tensor fasciae latae and piriformis. They all pull on your femur, or thigh bone, inward toward the midline of your body. To do an internal hip rotation exercise, sit with your left side facing a cable pulley machine. Attach an ankle cuff to your right ankle and then pull the handle towards the right as far as you can.

    Hip External Rotation

    • Many small muscles allow for external hip rotation, including the gemellus superior and inferior, obturators internus and externus, and the quadratus femoris. Each of these muscles pull on your femur away from the center of your body. To perform an external hip rotation exercise, sit with your right side facing a cable pulley machine. Attach an ankle cuff to your right ankle and then pull the handle to the left as much as you can.