What Is Pronator Syndrome?
Pronator syndrome, also known as pronator teres syndrome (PST), occurs when the median nerve is compressed in the upper forearm. The median nerve is one of the three nerves that allows our upper extremity to sense and move—it begins in the upper arms and its branches extend into the fingers. When this nerve becomes entrapped at the elbow, a number of symptoms can present themselves. These are typically most noticeable and bothersome when trying to rotate the palms from facing upward to turning down towards the floor.
Signs & Symptoms
The symptoms of pronator syndrome are similar to those of carpal tunnel syndrome, which occurs when the median nerve is compressed at the wrist. However, with pronator syndrome these symptoms tend to affect both the hand and the forearm. Common signs that the median nerve is being entrapped at the elbow include the following:
- Aching pain in the forearm
- Tingling in the thumb and index finger
- Numbness in the hand
- Weakness in the thumb and index finger
Pronator syndrome can occur in both men and women, but it is most common in women over the age of 40. The condition is caused by compression of the median nerve, usually by swollen and inflamed structures around the elbow. Certain underlying conditions such as hypothyroidism and diabetes are considered risk factors of pronator syndrome. Pronator syndrome is most prevalent in those who regularly take part in activities that require repetitive pronation (turning the palm to face the floor) while flexing the fingers, such as when grasping an object.
Common job roles that are especially prone to developing pronator syndrome include carpenters and mechanics. Sports like weight lifting, rowing, and those that use rackets are also susceptible to the condition. In addition, pronator syndrome can be caused by other factors such as forearm trauma, tumors, and bony abnormalities.
To make a diagnosis, one of our reconstructive hand surgeons will perform a physical examination and take imaging tests to thoroughly evaluate what may be causing your symptoms. Pronator syndrome is most often determined based on the physical exam, but imaging tests, such as an X-ray or MRI, or nerve conduction studies may help your doctor better understand the structure of the area and if another problem may be contributing. For mild to moderate cases of pronator syndrome, our surgeons will first recommend conservative treatments to attempt resolution of the condition. These non-surgical methods may include one or more of the following:
- Rest from the activity causing symptoms
- Splinting to prevent the forearm from rotating
- Anti-inflammatory pain medications
- Hand therapy
Your progress will be monitored over the course of three to six months; most of the time the symptoms will resolve. If these methods are not enough to improve the condition—or your initial symptoms include difficulty moving the arm or hand—surgery may be recommended to relieve the pressure on the median nerve. This typically entails a minimally invasive procedure designed to decompress the nerve at the elbow to restore optimal function.
The most beneficial treatment option for your condition will be determined once your surgeon has had the opportunity to assess your symptoms as well as the results of your imaging tests. If you have any questions about pronator syndrome, or would like to schedule an appointment with one of our experienced surgeons, please contact the Institute for Hand Surgery at LIPSG.