Whole Arm Painful & Tingling? Be Aware of Thoracic Outlet Syndrome (TOS)!

Do your hands easily get numb and fatigue with over-head activities? Do you also constantly feel shoulder and neck pain at the end of the day? Be careful! You may be developing Thoracic Outlet Syndrome (TOS)!

TOS can easily be misdiagnosed due to its vague symptoms or similar signs like carpal tunnel syndrome, it certainly helps a lot when you follow this article to assess your symptoms!

⭐ What is TOS ?

TOS is a condition when your nerves or vessels are compressed in between your neck and armpit area, this region is called Thoracic Outlet. As the picture bellow showed, there are three major types of TOS: neurologic, venous and arterial.

Thoracic Outlet Syndrome

⭐ Signs & Symptoms 

✨ Nerve Compression  (most common type)

* Vague, aching pain in the neck, shoulder, arm, or hand.

* Numbness, or tingling over inside of the forearm or hand, and hand weakness.

✨ Blood Vessels Compression

Reduced blood flow out of your arm, resulting in swelling and redness.

Affected hand may feel cold and easily fatigued.

Thoracic Outlet Syndrome

⭐ Causes of TOS

Anything that narrows your thoracic outlet area can cause TOS, such as

✨ Traumatic injury (car accident)

✨ Congenital problem (abnormal first rib)

 Poor posture & repetitive strain → The part we can do to prevent or treat TOS!


⭐ Easy Self-Testing 

✨ Roos’ Test: Raises your arms to 90 degrees of shoulder abduction and external rotation (surrendering position), then opens and closes your hands for up to 3 minutes. It’s positive if you experience pain, heaviness or numbness in the shoulder, arm or hands. (video credit: MSK Medicine)

⭐ High Risk Population 

✨ Female

✨ Pregnancy

✨ Occupations with elevated arms 

* Painter, hairdresser, welder, assembling line workers or dental works.


✨ Occupations with constant poor posture

* Musician, or prolonged computer user (software engineer, accountant…).


✨ Sports with repetitive overhead activities

* Volley ball, badminton or swimming.

⭐ In fact, you may already noticed TOS is closely related to your daily life activities. Delayed treatment for TOS can lead to severe pain and even muscle atrophy in your affected arm!
Next, how do we treat TOS ?



Laulan, J., Fouquet, B., Rodaix, C., Jauffret, P., Roquelaure, Y., & Descatha, A. (2011). Thoracic outlet syndrome: definition, aetiological factors, diagnosis, management and occupational impact. Journal of Occupational Rehabilitation, 21(3), 366–373.

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" !