Carpal Tunnel vs. Pronator Teres Syndrome

“My hand is tingling and numb, am I having carpal tunnel syndrome ?! “

As carpal tunnel syndrome (CTS) is the most common nerve entrapment problem in our upper extremity. One of the classic symptoms is tingling and numbness over the first 3 ½ fingers (thumb, index, middle, and half of ring fingers). Therefore, it is reasonable that healthcare providers usually suspect people may have CTS when they are complaining about such symptoms.


However, even clinicians can mis-diagnose your problem and blame the wrong culprit. 


Pronator Teres Syndrome (PTS) is caused by compression of the median nerve by pronator teres muscle in the forearm. It has very similar neuropathic symptoms like CTS. Therefore, PTS is usually under-diagnosed compared to CTS.


⭐ Etiology of Pronator Teres Syndrome pronator teres syndrome

Pronator teres muscle functioning as a “rotator” that turns your forearm to “palm down” position (pronation).

PTS is usually associated with quick and repetitive grasping or forceful pronation movements (such as prolonged hammering, weight lifting, racquet sports or rowing). Which leads to hypertrophic pronator teres muscle, causing overly stressed and compression of the median nerve.

This nerve entrapment issue can also be caused by local trauma to the forearm, as well as in patients going through anticoagulation therapy and renal dialysis.


⭐ Symptoms of Pronator Teres Syndrome 

The common symptoms of PTS are:

* Pain in the proximal volar (palm side) aspect of the forearm.

* Pain is commonly aggravated by repetitive & resistive forearm rotation.

* Thumb, Index & middle finger weakness. (usually no muscle wasting)

* Tingling & numbness over first 3 ½ fingers. (Can be reproduced when tapping proximal forearm – tinel’s sign)

pronator teres syndrome


⭐ How to Differentiate CTS & PTS ?

The table below summarized the differences between CTS and PTS.

pronator teres syndrome


However, you should also be aware of a problem called Double Crush Syndrome, which means the nerve was trapped in both or even multiple sites. Therefore a thorough physical examination, nerve conduction test and advanced imaging examination are important to ensure the accuracy of diagnosis.

Fortunately, studies showed conservative treatment can help 50% of patients with PTS to recover in 4 months. Our next article will introduce common physical examination and rehabilitation for PTS.


⭐ References

* Dididze M, Sherman Al. Pronator Teres Syndrome. [Updated 2020 Jan 23]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from:

* Hartz CR, Linscheid RL, Gramse RR, Daube JR. (1981). The pronator teres syndrome: compressive neuropathy of the median nerve. J Bone Joint Surg Am, 63(6), 885-890.

* Lee, M. J., & Lastayo, P. C. (2004). Pronator Syndrome and Other Nerve Compressions That Mimic Carpal Tunnel Syndrome. Journal of Orthopaedic & Sports Physical Therapy34(10), 601–609




Andrew Tan, OTR/L, CHT, CKTP, CEAS
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Andrew Tan, OTR/L, CHT, CKTP, CEAS

The founder of "Rehab For A Better Life", specialized in ergonomic consultation, rehabilitation for upper extremity injuries, sports injuries and work-related injuries. Andrew believes rehab-related knowledge should be easy to learn and follow at home, because "knowledge is power only when we can share it" !