Proximal median nerve compression is easy to miss—unless you connect the right dots
Do you have chronic pain or aching in your arm below your elbow? Especially after certain movements or activities? You might be dealing with proximal median nerve compression.
It has several other names—you may have also heard it called pronator syndrome or pronator teres syndrome. That’s when the median nerve gets trapped at your elbow.
Your median nerve is a long nerve that travels from your upper spine, through the middle of your arm, and into your hand. It journeys through lots of moving parts. Unfortunately, this makes it easy for it to get mechanically entrapped.
An injury, repetitive motion or inflammation at any part of the nerve risks pinching it. Any of these problems can hurt the nerve directly, or even restrict blood flow to the nerve, causing damage.
Proximal median nerve compression frequently overlaps with other kinds of nerve pinching,1 like:
- Carpal tunnel syndrome—where the median nerve gets pinched at the wrist.
- Cubital tunnel syndrome—where the ulnar nerve gets pinched at the elbow.
- Ulnar tunnel syndrome—an uncommon ulnar nerve pinched at the pinky side of the wrist.
- Anterior interosseous syndrome—where one of the median nerve branches gets pinched somewhere in the forearm.
The most common places the median nerve can get compressed are just above the elbow, just below the elbow, and at the wrist.
What are median nerve compression symptoms?
Many patients describe pronator syndrome as a dull aching pain inside of the forearm closer to the elbow. This aching and pain can be worse with activity. The pain can come with numbness, prickling, or tingling pain. It often gets misdiagnosed, since the symptoms can be vague.
Carpal tunnel syndrome is a common misdiagnosis. The symptoms are almost the same. But with pronator syndrome, numbness can go all the way from your elbow to your forearm, and into your palm. The pain from pronator syndrome usually won’t wake you up at night, as carpal tunnel syndrome does. Also, carpal tunnel syndrome is a distal median nerve injury, rather than a proximal median nerve injury.2
If the median nerve compression is from an elbow injury, you’ll often see fingers involved.3In a child, a classic sign is the “pointing index sign”. The child will be able to close their hand except for their pointer finger.
In an adult, you may see the “hand of benediction”. This is where, when a patient tries to make a fist, the pinky and ring finger may bend without a problem. However, the middle pointer and thumb will only bend slightly, if at all.
If the nerve is compressed in, the wrist (as with carpal tunnel syndrome), a patient will struggle to get their thumb to touch their palm.
If the anterior interosseous syndrome is involved, a patient will struggle to make an “OK” posture with their hand.<sup4
What can cause pronator syndrome/pronator teres syndrome?
Repetitive tasks and injuries are the key culprits.5
Some repetitive tasks that can cause medial nerve compression include:
- Throwing motions. Athletic injuries, like throwing a baseball over and over, can easily involve the median nerve. Similar motions, like nailing with a hammer, can mirror the movement.
- Gripping. Some common repetitive activities include working out with weights or equipment with bars, holding handles, and loading trucks.
- Weight lifting. Certain exercises can bulk up your muscles enough to compress the median nerve.
The median nerve is frequently pinched by a one-time injury. These can look like:6
- Suddenly extending your elbow. Boxing, forcefully throwing balls, incorrectly lifting weights, and catching yourself while falling are common ways to over-extend your elbow.
- Fracturing your humerus. Ever broken the bone in your upper arm? The connection between that bone and your upper arm can easily pinch that nerve.
- A supracondylar fracture. This is a kind of humerus fracture—and it’s the most common upper arm fracture in kids. It’s usually caused by falling right on the elbow or getting hit directly on the elbow. A classic sign is the “pointing index sign”.
- A tourniquet that was in place for too long. Tourniquets that get forgotten strangulate your nerves. When this problem comes up, it’s often during blood donations or surgery.
- Elbow or shoulder dislocation. A dislocation can seriously disrupt a nerve’s path, causing painful pinching.
Is there a median nerve compression test?
Your doctor will check for the symptoms, as mentioned above, and may order some nerve testing. They may refer you to a nerve specialist as well.
Since different nerve compression affects different areas, your doctor may test your ability to do certain movements. Median nerve compression generally affects your thumb, pointer finger, and part of your middle finger. Nerve compression often shows up as worsened mobility and increased pain with certain movements.
To test your nerve function, your doctor may have you take a nerve conduction study. This can help to determine whether a nerve is damaged.
Your doctor may order an MRI to get a look under the surface. This can help show your doctor if anything is pinching the nerve.
Electromyography (EMG) is another option. This can show your doctor whether nerve damage is impacting your muscles.
What’s available for pronator syndrome/pronator teres syndrome treatment?
Your doctor will try the least invasive treatments first. Anti-inflammatory medications, exercises, and lifestyle adjustments may help relieve pain. Many forms of nerve compression resolve on their own.
But if an injury is causing your nerve pinching, conservative treatment may not relieve your pain. Nerve surgery usually relieves pain and restores function quickly. The surgery is often as simple as moving the nerve or removing the pinching object.
Nevada Nerve Surgeons treat proximal medial nerve compression
If you’re having pain and movement problems around your elbow or in your fingers, and it’s not resolved in several months, don’t let it get worse. Talk to your doctor about getting a referral, or contact us directly at 702-505-8781.
We look forward to speaking with you.
[This article isn’t a replacement for diagnosis or a physician-directed treatment plan. If you have health concerns or questions, please talk to a physician.]
References: