The Obturator Internus Muscle
The Obturator Internus Muscle
The Obturator Internus (OI) muscle can often be the culprit when it comes to pelvic, hip or low back pain. It can sometimes even lead to bladder and bowel urgency and leakage.
So what is the OI Muscle?
OI is a deep hip stabiliser muscle. It is primarily responsible for keeping your hip and knee in good alignment with functional tasks such as walking, climbing stairs, squatting, and lunging. Located deep inside your pelvis, it lives right next door to the pelvic floor. Due to this close proximity the OI can influence pelvic floor muscle and pelvic nerve function. To keep the pelvic floor and pelvic nerves happy, your OI should be strong but supple!
The Pudendal Nerve and the OI Muscle
Between the pelvic floor and the OI muscle is a canal, the Alcocks Canal, that houses the pudendal nerve. The pudendal nerve is an important pelvic nerve which supplies sensation to the genitals and innervates your urethral and anal sphincters. Your sphincters give you control over your bladder and bowels. The Alcocks Cana is made up of fascia from the OI muscle. If the OI is tight, it can increase the pressure on the pudendal nerve, leading to sensory changes and/or discomfort in the genitals and bladder and bowel urgency and leakage.
How do I know if my OI is tight?
Patients with tight OI muscles, often present with hip, proximal groin/hamstring, low back or pelvic pain.
In the absence of pain, if you notice that your knees turn in when you squat or lunge it may be weakness and/or tightness in the OI contributing to your poor hip/knee stability.
The best way to know if your OI is a contributing factor to your pain or pelvic floor dysfunction is to have your muscles assessed by a pelvic floor physiotherapist.
How can Pelvic Floor Physiotherapy Help?
Assessment
Due to it’s position in the pelvis, the best way to assess the OI is via an internal vaginal examination in women, or an internal rectal examination in men.
An internal exam is a special assessment tool, that can only be performed by specially trained professionals, for this reason it is not a standard part of a hip assessment with a non-pelvic health physiotherapist.
With your explicit consent, your physiotherapist can complete an internal examination of all your pelvic floor muscles. To access your OI, your physio will angle their examining finger around towards the hip and can palpate this muscle to see if it is supple and non-tender, they may also ask you to rotate your leg in an out to assess for myofascial tension.
Your physiotherapist can also perform a functional assessment, looking at pelvic alignment and knee control with walking, single leg squat and lunges.
We can also assess the external rotation strength of the hip, using a PowerTrack device, which can tell your physio if your OI muscles have sufficient power and strength.
Treatment
Your OI can be problematic when it is tight and/or weak! Treatment for OI dysfunction is to release and strengthen!
Your physio may do some internal release work on your OI muscles in your appointments; You may also be prescribed a Therawand to continue release work at home.
Once the OI muscles are more relaxed, your physio will prescribe a deep hip strengthening program to retrain your muscles.
The Pelvic Studio also offer small group classes, allowing you to complete your exercise rehab in a supportive and supervised environment.