Obturator Internus: Out of Sight, but Keep It in Mind

By Dan Hellman

Pity the obturator internus muscle. It just doesn’t get the attention and care that the quads, pecs and abs receive. Why is that? First, it’s an internal muscle, as the name implies. It can’t be seen or admired when flexed before a mirror. And sadly, most people in the rehabilitation and fitness world don’t fully understand its anatomy and function. So it’s out of sight, but let’s please keep it in mind.

Why It Matters

Here is why this matters: Taking proper care of this muscle will help avoid and alleviate hip pain. The obturator internus, piriformis, levator ani and coccygeus form the pelvic diaphragm and are intimate with the organs and glands of the pelvis. These muscles also play an important role in sports performance because they stabilize the pelvis.

I help my patients use myofascial stretching of the obturator internus to benefit all of its many fascial attachments. But myofascial stretching is not enough. The obturator internus also needs to be reinforced with exercise. Reinforcing it in an-open chain position is great for sports performance, and using a closed-chain position is very effective for pumping, which also benefits the organs and glands of the pelvis.

Obturator Internus Anatomy and Function

The obturator internus is a fan-shaped muscle that originates on the medial surface of the pubis around the obturator foramen. It then runs posterior-lateral and attaches to the inner surface of the greater trochanter of the femur. And it has many important fascial connections.  The obturator internus and five other muscles are known as the “deep six,” and they are responsible for external rotation, flexion, extension and abduction of the hip. They also stabilize the hip joint.

The Pudendal Nerve and Alcock’s Canal

The internal pudendal vessels and pudendal nerve cross the obturator internus enclosed in a special canal called Alcock’s canal, formed by the obturator fascia.  The pudendal nerve originates in the branches of the S2, S3 and S4 vertebrae. It provides motor stimulation to the muscles of the perineum and is the primary sensory stimulator of the genitalia.  The pudendal nerve often becomes “trapped” by the fascia of the obturator internus, which can cause all sorts of strange pelvic symptoms.  Is anyone having an “ah-hah!” moment now?

The Pudendal Nerve and Neuralgia

How does the obturator internus work with the pudendal nerve to cause pelvic discomfort? The pudendal nerve is really the key. It branches into three smaller nerves:

• The inferior rectal nerve, supplying the rectum, skin and anal sphincter;
• The perineal nerve, supplying the perineum, urethra, female vagina and labia, and male scrotum;
• The dorsal nerve, supplying the clitoris or penis.

The sensory symptoms could manifest as itching, burning, tingling, cold sensations or shooting pains into the groin, abdomen, legs or buttocks.  The pudendal nerve is the only nerve that has both somatic (body) and autonomic fiber, meaning the person may not just suffer these localized discomforts, but also things like increased heart rate or blood pressure, constipation and overall sense of malaise. 

Treatment of the Obturator Internus

If you are experiencing any of these symptoms, it is important to find a manual therapist who knows how treat the area.  But remember that you are always your best therapist, and a good manual therapist should be able to show you how to perform the myofascial stretching and exercises that I described earlier.

As you can tell, the function of the obturator internus is quite complex, and anyone experiencing pelvic discomfort that might be related to this muscle should contact a skilled therapist. I’m happy to help. Feel free to contact us. Fill out the form on our Contact page or simply email us at info@h3bydan.com for a free consultation or referral to a qualified practitioner in your area.

Pictured: A myofascial stretch combined with exercise is effective in treating pain and dysfunction related to the of the obturator internus muscle.