What Is Thoracic Outlet Syndrome?

Co-author: Payton Hufnagel, SPT

Thoracic outlet syndrome (TOS) affects approximately 8% of the population, most commonly women between 20 and 50 years old. In this blog, we’ll discuss the causes and types of TOS, its presentation, and how physical therapy can help those with TOS symptoms get back to doing what they love.

What Is Thoracic Outlet Syndrome?

Thoracic Outlet Syndrome (TOS) is caused by compression of nerves or blood vessels as they exit the spaces between the collarbone and first rib. TOS can occur as a result of three spaces between the clavicle (collarbone) and the first rib. These areas include a group of small neck muscles, costoclavicular space, and the spaces above and around the collarbone. Thoracic outlet syndrome can occur as a result of trauma, anatomy, or repetitive motions. Traumatic causes include motor vehicle accident, hemorrhage, hematoma, displaced fracture, or Pancoast tumor. Repetitive upper extremity motions can result in muscular hypertrophy, swelling, or small hemorrhages leading to TOS. Anatomical variants such as the presence of a cervical rib and variations of the scalene musculature can also cause TOS.

There are three different types of thoracic outlet syndrome.

• Neurogenic: the most common type (>90% of cases) Signs and symptoms include upper extremity paresthesia, neck pain, trapezius pain, shoulder/arm pain, supraclavicular pain, chest pain, and occipital headache. Neurogenic TOS can present in both arms.
• Venous: (3-5% of cases) resulting from subclavian vein compression. Venous TOS is more commonly found in men, typically affects the dominant upper extremity, and is associated with repetitive movements (including throwing and swimming). Signs and symptoms include upper extremity swelling, blueness in the color of the arm, pain, and typically in one arm.
• Arterial: (1-2% of cases) caused by subclavian artery compression. Arterial TOS can present with both vascular and neurogenic symptoms.

Physical Therapy Examination And Treatment

Thoracic outlet syndrome treatment typically begins with conservative management unless symptoms are severe or debilitating. Physical therapy evaluation may include examination of the neck and upper extremities, posture, skin temperature and color, and muscular differences from side to side. Testing can help to determine which structures are involved, such as muscles and nerves. Physical therapy focuses on symptom reduction, strengthening, stretching, and neck and thoracic spine mobilization. Activities are geared toward improving scapular and muscular control, motor control of the shoulders, and decreased tension in overused muscles, and improved strength in weaker muscles. Strengthening activities typically target some of the muscles above the shoulder blade that attach to the neck to improve overhead motion and space in that area for the nerves and blood vessels that may be involved. Stretching techniques should be applied to the pectoralis muscles, lower trapezius, and scalenes, which are structures that can decrease space in the thoracic outlet. Approximately 90% of individuals experience resolution of symptoms with conservative management.

If you experience pain that gets in the way of performing your sport or daily activities, connect with our team of movement experts who can help. Start by scheduling a free assessment where one of our licensed physical therapists will assess your condition and help you determine the best course of action to help you feel better faster. Free assessments are available in-clinic and virtually through our telehealth platform.

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*Per federal guidelines, beneficiaries of plans such as Medicare, Medicaid, Tricare, VHA and other federally funded plans are not eligible for free assessments.

The Athletico blog is an educational resource written by Athletico employees. Athletico bloggers are licensed professionals who abide by the code of ethics outlined by their respective professional associations. The content published in blog posts represents the opinion of the individual author based on their expertise and experience. The content provided in this blog is for informational purposes only, does not constitute medical advice and should not be relied on for making personal health decisions.

References:
1. Cleveland Clinic. Venous thoracic outlet syndrome: Causes and symptoms. 2022. https://my.clevelandclinic.org/health/diseases/22317-venous-thoracic-outlet-syndrome
2. Jones MR, Prabhakar A, Viswanath O, et al. Thoracic Outlet Syndrome: A Comprehensive Review of Pathophysiology, Diagnosis, and Treatment. Pain Ther. 2019;8(1):5-18. doi:10.1007/s40122-019-0124-2
3. Ohman JW, Thompson RW. Thoracic Outlet Syndrome in the Overhead Athlete: Diagnosis and Treatment Recommendations. Curr Rev Musculoskelet Med. 2020;13(4):457-471. doi:10.1007/s12178-020-09643-x