I learned something new at my pelvic floor physical therapist visit the other day: the existence of a muscle and it’s important role in ALL of my major running injuries the past 4 years—the obturator internus muscle.
I didn’t know it existed: I thought my hamstring muscles ended and my glutes began. But no, there is a tiny hip muscle there that plays a starring role in running and, unfortunately, many running injuries—including women who have had babies.
I had to share what I learned about the obturator internus muscle and how it is core issue that has kept me sidelined for so long in running. I wanted to shout about it from the mountaintops, but instead I settled for Instagram.
I called it a deep tiny hip muscle AND many people already know what I was referring to! Many fellow mother runners too had learned that the obturator internus muscle was behind many of their injuries, too!
But more education needs to be done. I feel passionate about this because I have lived the frustration of shadow boxing injuries—spending countless hours and dollars trying to rehab an injury, get strong in the right places, only to get hurt and set back again.
My Running Injury Story
Here’s a quick overview of my running injury story. About a year, year and a half, after having my second child, I began running more seriously. Within a year of that time (also when starting The Mother Runners), I tore my right high hamstring.
After 1.5 years of rehabbing that, I began running again and soon tore my right plantar fascia. I returned with a solid year of running and two marathon cycles only to suffer severe hip pain, and a tear of my right hip labrum. Also, I suffered from what was diagnosed as compartment syndrome in my RIGHT quad, which I diligently managed as best I could. I also struggled with recurring low back pain and sciatic pain.
Related: How I am Coping with Being Injured
I saw many specialists and physical therapists. Finally, with my hip injury, I was out of options. I knew it was time to see a pelvic floor physical therapist. After a thorough physical examination, she shared that my right obturator muscle was weak and tight, as along with weak pelvic floor muscles on the right.
This correlated with my running injuries AND the fact that I felt like my right leg internally rotated too much. Light bulbs went off everywhere.
We began working together to turn my obturator internus muscle back on and back to full strength.
In this article, I aim to share the basics of the obturator internus muscle so that you have the knowledge to ask the right questions should you be dealing with a running injury or imbalance so you don’t have to shadowbox your injury.
I got with pelvic floor physical therapist, Dr. Carrie Pagliano to answer:
- What is the obturator internus muscle and its role in running?
- How is the obturator internus connected to the pelvic floor?
- What running injuries are commonly related to the obturator internus muscle?
- How can you tell if you have a weak, tight, or “turned off” obturator internus?
- How can you fix a weak or tight obturator internus?
- And, I share some exercises to strengthen or recruit an obturator internus.
Reading this article does not replace seeing a qualified physical therapist or pelvic floor physical therapist, so please see one. Read more about how to find a PF PT near you here. I am not a doctor, though I did talk with one for this article. My hope is the expertise shared here can guide you in how to get to the core of your running injuries, too.
Okay, let’s go!
What is the obturator internus muscle?
The obturator internus muscle (or OI) is a deep hip muscle that acts as a hip stabilizer, with its primary function as external rotation of the hip. It is one of six external hip rotators that work together to stabilize the hip when walking, standing, and yes, running.
The OI is thereby essential for preventing injury in these movements. It can’t be easily isolated for stretching or strengthening because it is attached to other hips muscles, you must target both the hip and gluteal muscles of the entire region to rehab it.
The OI is a flat fan-shaped muscle that originates in the internal portion of the pelvis turning into a tendon and attaching to the side of your hip. You can most easily see it or feel it in the posterior thigh bone near the insertion point of the high hamstring. This video does a great job of explaining where the OI is and what it does.
Note, there is also an obturator externus muscle which externally rotates the hip joint as well, but not in the flexion or neutral position of the hip, but not the hip extension.
Related: Can You Run with Hip Pain?
How is the obturator internus muscle connected to the pelvic floor?
The obturator internus muscle is technically a pelvic floor muscle as it is a deep muscle of hip joint which is part of lateral wall of pelvis, says Dr. Pagliano. It his at the insertion site of several pubic floor muscles, having many fascial attachments with the pelvic floor levator ani muscles.
“Anatomically, they’re essentially neighbors,” she explains.
Research in the Journal of Women’s & Pelvic Health Physical Therapy shows that if you are able to strengthen the obturator internus, you may also strengthen the pelvic floor and minimize pelvic floor dysfunction, pelvic pain, and other pelvic issues.
What is the role of the obturator internus muscle in running?
The obturator internus plays a major role in running—it functions as the hip rotator, explains Dr. Pagliano.
The OI’s main function is to help externally rotate the femur when the hip is extended and then abduct the femur when the hip is flexed (move the muscles away from midline of the body).
Think about how you run. When you extend your leg out, the OI works to roll your thigh as it strikes the ground, helping your leg move with force and then absorb the force in a controlled way.
When your thigh moves in an uncontrolled way thanks to weakness of the hip stabilizer muscles such as the obturator internus, that is when muscles strains and tears like a labrum tear can occur due to overuse and excess friction and force.
Ok, so what running injuries may be caused by a weak or tight obturator internus?
Injury of the actual obturator internus is rare, but the OI may be behind or associated with many common running injuries and pain. The OI can also be mistaken for many common running injuries.
If you suffer from hip [ain, hamstring pain, IT band syndrome and other glute/piriformis muscle pain, low back pain, leg pain, and groin pain, it’s important to have your OI examined, notes Pagliano. It could be the culprit of or contributor to the pain.
How can you tell if you need to strengthen your obturator internus? What about release your obturator internus?
Dr. Pagliano says the only way to truly know if your obturator internus is weak or tight is to do a medical assessment and/or imaging. It’s not common you can pinpoint your pain as obturator internus pain.
Though there are symptoms of a weak obturator internus or OI dysfunction including:
- bladder control issues
- bowel control issues
- painful intercourse
- referred pain to the tailbones and sit bones
- hip joint, glute, and groin pain
- Pudendal nerve pain
- pelvic pain
My symptoms included hip, back, and sciatic nerve pain and pudendal nerve pain.
A pelvic floor physical therapist can do a deep palpitation of the lateral wall of your pelvis through the vaginal wall to assess the muscle tone, tightness, and strength of your OI.“If you abduct/slightly externally rotate your hip, you can feel the OI muscle pop into your palpating finger,” she explains.
This is not something you can really do yourself. You need a skilled PT who knows what to look for to assess the health of your obturator internus.
For me, my OI was not being recruited in the right order while running. This caused by obturator internus to be confused as to what to do and when, leading to it becoming weak and stressed out, in a sense.
If you have a weak OI or need motor control improvements, your PT will direct to how to do that.
Your PT or a skilled massage therapist can also perform an obturator internus release. This is done by finding the OI trigger point and massaging it in a circular motion. To do this, your healthcare provider will most likely have you in a side-lying position with a pillow between your knees.
Are women more likely to have obturator internus issues after having children?
Some women are more likely to have issues with their obturator internus after childbirth because pregnancy impacts the pelvic floor, says Dr. Pagliano.
The weight of your growing belly causes your hips to have an anterior rotation which can shorten the OI, for example.
If you have had prior hip or pelvic floor issues before pregnancy, then you are more at risk for OI issues. Your birth mode, birth experience, and level of trauma also can impact the health of your obturator internus.
How do you fix a weak obturator internus?
If you have a weak OI, there are exercises you can do to strengthen it. Dr. Pagliano recommends starting with single leg training, ideally with a physical therapist skilled with working with runners.
Here are some exercises to help ensure you have a strong obturator internus.
- Lying on your side with your legs bent and a band around your thighs,
- raise the top leg until you feel tension,
- pause for a few seconds, slowly lower.
- Do 20 reps on each side.
Isometric External Hip Rotation
- Seated in a chair with a band around your thighs, push your knees out.
- Hold for ten seconds.
- Slowly close your legs and repeat 10-20 times.
Banded Monster Walk
- With a band around your knees and legs at hip distance apart,
- move to one side of the room moving sideways with a big side step so you feel your glutes work.
- Do 20-30 reps on each side.
Working with a PT can also instruct you in how to regain motor control of your OI so you recruit the muscles in the right order when running.
Here are the OI motor control exercises I am doing:
Obturator Internus Activation
- Lay down with one leg straight and one leg bent (this helps to isolate the working leg)
- Activate the OI (lower glut/hamstring connection) of the bent leg. Try hard not to recruit the hip flexors or quads.
- Repeat 10 times.
Obturator Internus Bridge
- Once you have nailed the OI activation, repeat those step and add a slight lift.
- Lift/roll the hip (only the bent leg) just enough to slide piece of paper under the hip
- Knee should stay stationary (pointing to the ceiling).
- Repeat 50 times.
Standing Obturator Internus Activation
- Once you nail that, stand with your legs hip width apart.
- Bend one knee, activate your glutes, and slowly rotate the hip out.
- Return back by close your bent knee to your other leg.
- Repeat 10-20 times.
- Advance this by adding a hip thrust and running arm when you come out of the rotation.
I hope this information can help you ask the right questions if you are trying to find the cause of your injury. Further investigation of these muscles can help you ask the next appropriate question of your health care provider and hopefully get you on the right path to healing.
If you want guidance with your running goals, check out my run coaching services. Also, be sure to check out my free training plans:
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- After a Break Training Plan
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