Everyone has heard of carpal tunnel syndrome, but very few have heard of pronator teres syndrome. It is not common, but I have seen and treated several patients with it. It mimics carpal tunnel syndrome and is, probably, mistaken for it often. Read on to learn more about pronator teres syndrome. Let’s start with anatomy!
What is the pronator teres?
The pronator teres is a muscle on the palmer side of the forearm. It has two head which means that it has two upper attachment sites near the elbow. One head attaches to the medial epicondyle of the humerus (the upper arm bone). The medial epicondyle is the bony bump on the inside of the elbow when the palm faces up. The other head attaches to the coronoid process of the ulna (one of the forearm bones). The coronoid process is a bony notch near the top of the ulna at the elbow. The muscle starts at the two heads, then combines and travels down to attach to the middle of the outside of the radius (the other forearm bone).
“RCSI – Drawing Flexor muscles and tendons of forearm – English labels” by Royal College of Surgeons of Ireland, license: CC BY-NC-SA
The pronator teres pronates the forearm and helps to flex the elbow. Pronation is the act of rotating the forearm so that the palm is facing downward. Elbow flexion is the action of moving the forearm closer to the upper arm (e.g. bicep curl motion).
What is the median nerve?
The median nerve is one of the major nerves of the upper extremity. It begins near the armpit and travels all the way down to the hand. As it travels down the arm, the median nerve will pass between the two heads of the pronator teres.
The median nerve innervates many of the muscles of the forearm and hand, including the pronator teres. It provides sensation to half of the palm on the thumb side. The fingertips and palmer side of the thumb, index finger, middle finger, and half of the ring finger also get their sensation from the median nerve.
What is pronator teres syndrome?
Pronator teres syndrome is a compression neuropathy of the median nerve. Neuropathy means that there is some kind of irritation to the nerve that is causing pain, weakness, numbness, or tingling. In the case of pronator teres syndrome, it is a compression of the median nerve as it passes between the two heads of the muscle.
Pronator teres syndrome typically occurs after repetitive grasping with forceful movements of the elbow and forearm. Examples of the type of movements that could cause pronator teres syndrome include hammering, tennis, rowing, and washing dishes. However, pronator teres syndrome could also occur after trauma to the elbow and forearm.
What are the symptoms of pronator teres syndrome?
There are several symptoms associated with pronator teres syndrome. These include:
- Pain in the palmer side of the forearm
- Pain in the elbow
- Pain increases with elbow movements and decreases with rest
- No pain at night
- Changes in sensation in the fingers and palm of the hand
- Thumb weakness
Is it pronator teres syndrome or carpal tunnel syndrome?
The symptoms from pronator teres syndrome and carpal tunnel syndrome are very similar. However, there are some distinguishing symptoms that can help differentiate the two conditions. The following symptoms are present in pronator teres syndrome but not in carpal tunnel syndrome.
- Changes in sensation in the palm of the hand
- Aching pain over the palmer side of the forearm near the elbow
- No symptoms at night
- Pain worsens with elbow movements
Who gets pronator teres syndrome?
Pronator teres syndrome is relatively rare. It is unknown how prevalent it is because it is often mistaken for carpal tunnel syndrome. However, there are a couple risk factors associated with pronator teres syndrome. These include:
- Manual occupations that require forceful grasping and pronation
- g., mechanics and carpenters
- Certain sports
- Racquet sports, rowing, weightlifting, pitching
- Commonly associated with medial epicondylitis (golfer’s elbow)
Who should I see?
- Physical therapy – This would be my first stop. Physical therapy can help decrease pain and inflammation with techniques including manual therapy and dry needling. PT can evaluate and address abnormal joint mobility, muscle weakness, muscle tone, and flexibility. With pronator teres syndrome it is important to decrease the amount of work this muscle is performing. Your PT can help you activate other muscles to decrease the load on the pronator teres. They can assess your posture during work or sports to prevent the problem from happening again.
- Orthopedic physician – An orthopedist might be necessary if the condition is not responding to physical therapy. Your physician can prescribe medication, give a steroid injection, or order imaging if needed. Surgery is an option if all conservative measures fail.
What can I do?
- Relative rest – Resting the area to decrease further pain and damage from occurring is one of the best ways to treat pronator teres syndrome. Basically, stay away from the activities that are causing pain. This gives the muscle time to rest, relax, and heal. If you keep doing what is causing the injury, it is not going to get better. This might include not participating in your sport or changing how you perform a task or job. If you are not able to participate in your activity or sport, then you can supplement with non-irritating activities such as biking, walking, or jogging while your condition is being treated.
- Ice – Ice can help decrease pain and symptoms at the pronator teres. Ice the painful area for 15 to 20 minutes at a time. I would recommend using an ice pack several times per day if the pain is constant or is preventing you from participating in an activity. Ice immediately after activity.
- Posture – Having forward, rounded shoulders can lead to muscular imbalances in the shoulder and elbow. It decreases the ability of the scapular stabilizers to stabilize the shoulder joint. This causes the muscles at the elbow to work more. It also shortens the pectoralis major, pectoralis minor, and biceps and results in them getting tight. Stretching this area will make better posture more attainable. Below is a video showing how to stretch the pecs and biceps and also how to use a wall to check your posture.
- Soft tissue mobilization – Soft tissue mobilization helps release the muscles around the elbow and decreases the pressure on the nerve. Use a massage ball, lacrosse ball, tennis ball, or your own fingers to massagepainful areas all around the elbow. Spend a good 3 to 5 minutes rolling. Do not roll so hard that you bruise the area, but it should be a pretty painful sensation. Roll out the area no more than a few times a week. See the video below.
- Pronator teres stretch – Stretching out the pronator teres after rolling it out is a great way to lengthen the muscle. It is a good idea to perform soft tissue mobilization first because you will get a better stretch afterwards. Below is a video on how to stretch the pronator teres.
- Median nerve flossing – You can mobilize the median nerve to ensure that it is not entrapped in an area. Flossing will free-up the nerve if it is stuck and allow it to move along its pathway. Below is a video of median nerve flossing.
- Strengthen the rotator cuff and scapular stabilizers– Elbow injuries tend to occur because of weakness of the rotator cuff muscles and scapular stabilizers. These are the stabilizing muscles of the shoulder that allow the arm to reach, lift, and hold without injury or irritation. Using loop resistance bands and resistance bands can increase strength and difficulty.
In review
- The pronator teres is a muscle on the palmer side of the forearm.
- It has two head or two upper attachment sites near the elbow.
- The pronator teres pronates the forearm and helps to flex the elbow.
- The median nerve is one of the major nerves of the upper extremity.
- Pronator teres syndrome is a compression neuropathy of the median nerve.
- Symptoms of pronator teres syndrome include pain in the elbow and palmer side of the forearm.
- It can be mistaken for carpal tunnel syndrome.
- Physical therapy is a key component in treatment.
- An orthopedist would be necessary if the condition is not responding to physical therapy.
- There are things that you can do.
- Relative rest
- Ice
- Posture
- Soft tissue mobilization
- Pronator teres stretch
- Median nerve flossing
- Scapular stabilization strengthening
As always, If you have questions about the content of this post or any other musculoskeletal questions, please e-mail me.
Additional resources
https://www.orthobullets.com/hand/6020/pronator-syndrome
https://www.physio-pedia.com/Median_Nerve