Obturator Nerve

What is the obturator nerve?

Your obturator nerve is one of many peripheral nerves that run through your groin. It’s part of your peripheral nervous system. This system helps your brain communicate with the rest of your body.

The beginning of your obturator nerve (nerve root) is in your lumbar plexus. The lumbar plexus is a network of nerves that enables movement and sensation (innervation) in your lower limbs. These include your upper and lower leg along with your foot.

What other nerves run through the groin?

Other nerves in this area include your:

• Femoral nerve.
• Genitofemoral nerve.
• Ilioinguinal nerve.
• Lateral femoral nerve.

What is the obturator nerve’s function?

This nerve provides motor (muscle movement) and sensory (sensation) to your inner thigh.

For motor functions, muscles along your obturator nerve help you:

• Extend your leg at your knee.
• Flex at your hip.
• Maintain balance while standing and walking.
• Rotate your leg away from your body.
• Turn your foot away from your body.

For sensory functions, your obturator nerve provides sensation to your:

• Hip joints.
• Knee joints.
• Some of your skin covering the inside of your upper thighs (near your groin).

Are there other obturator nerve functions?

Healthcare providers may inject medication into your obturator nerve to lessen sensation (nerve block).

You may need an obturator nerve block to:

• Numb your groin before hip or knee procedures.
• Prevent involuntary leg jerks during pelvic surgery, including bladder cancer treatment.
• Relieve groin or thigh pain that doesn’t respond to standard therapies.
• Treat abnormal muscle tightness (spasticity) in your inner thigh. This sometimes occurs in people with multiple sclerosis.

What is the anatomy of the obturator nerve?

Nerve fibers that make up your obturator nerve start in the lower part of your spine. This includes spine bones (vertebrae) L2, L3 and L4.

Your obturator nerve’s course includes:

• Moving downward through psoas muscle tissue.
• Traveling behind your iliac artery and along the side of your pelvic wall.
• Entering your thigh region through a nearby tissue opening (obturator canal).

Once it reaches your groin area, your obturator nerve divides into three major branches:

• Anterior (front), provides sensation to muscles that help flex your hip.
• Cutaneous (skin), a further branch off of your anterior branch, provides sensation to your skin in the upper part of your inner thigh.
• Posterior (back), enables hip rotation and draws your thighs together.

Occasionally, your anterior branch also provides motor function for your pectineus muscles in your upper and inner thigh. Usually, your femoral (thigh) nerve provides movement for these muscles, but this can result as a rare variation of typical anatomy.

What conditions cause obturator nerve injury?

One of the main issues of an obturator nerve injury is neuropathic pain. Conditions that cause it include:

• Nerve entrapment: Nerves lose functioning due to abnormal pressure from nearby tissue, including swollen ligaments, and conditions in your pelvis such as endometriosis. Nerve compression can occur during pregnancy.
• Nerve damage (obturator neuropathy): Nerve damage can happen from abnormal wear and tear or a sudden injury.
• Obturator hernia: Abdominal tissue pushes through your obturator canal and presses on your obturator nerve.
• Pelvic trauma: Pelvic trauma may occur during childbirth, or from crush injuries such as car accidents, when internal bleeding leads to compression of the nerve.
• Pelvic tumors or cancer: Abnormal growths can form on your bladder, cervix, rectum and more.
• Sports injuries: These can occur in sports with frequent kicking, like football. It also happens in sports that involve long periods of sitting, like cycling or horseback riding.

Are there other issues that can cause obturator nerve injury?

Complications of pelvic surgery can affect your obturator nerve. This area has many complex structures. It offers limited space for navigating surgical instruments. Healthcare providers can injure your nerve while trying to access the surgical site. During surgery, your obturator nerve can be briefly compressed, stretched and, less often, damaged by surgical hardware.

Some surgeries, as well as childbirth, require leg positions in which your leg is positioned away from your body, putting tension on your obturator nerve.

Types of surgery that can cause obturator neuropathy include:

• Lymph node dissection in your groin for cervical cancer.
• Pelvic organ prolapse repair.
• Transobturator tape (TOT) operation for stress incontinence.
• Radical hysterectomy and prostatectomy.
• Uterine artery occlusion for the treatment of fibroids.

How can I protect my obturator nerve?

It might not be possible to prevent some causes of obturator neuropathy. Trauma from childbirth or crush injuries can be out of your control.

There are steps you can take to prevent obturator nerve sports injuries, including:

• Adjusting foot straps of horse saddles or bicycle seat height to minimize pressure on your pelvis.
• Taking time to properly warm-up before kicking sports.
• Strengthening legs and lower abdominal muscles with resistance training.
• Resting when you experience groin discomfort instead of trying to play through it.

When should I contact a healthcare provider about concerns with my obturator nerve?

Obturator neuropathy causes symptoms that linger and typically don’t improve over time.

Contact your healthcare provider if you experience:

• Claudication, or leg cramps, that occur with physical activity.
• Constant ache near your pubic bone.
• Discomfort that extends along your thigh.
• Muscle weakness in your thigh.
• Numbness in your thigh.
• Pain that gets worse with side-to-side leg movements.
• Sensation of pins and needles in your groin.