Thoracic Outlet Syndrome

The spine is divided into three distinct sections: cervical, thoracic, and lumbar. The segment of the spine that is located in the upper back and abdomen is known as the thoracic spine. This section sits between the cervical spine (neck) and the lumbar spine (lower back). This thoracic region of the body contains vital structures of the cardiovascular, respiratory and digestive systems and is protected by the thoracic wall (rib cage and other skin and muscles).

What is Thoracic Outlet Syndrome (TOS)?

The passageway in the upper chest located between the collarbone and first rib is referred to as the thoracic outlet. Nerves and blood vessels travel through this narrow space to exit the chest to the upper extremities. If space in this passageway becomes too narrow, blood vessels and nerves traveling through may become compressed, causing thoracic outlet syndrome. This can result in pain and numbness throughout the shoulders, arms, hands, and fingers.


The primary cause of TOS is an insufficient passageway for nerves and blood vessels when they are passing through the thoracic outlet. There are various reasons that this passageway can become too small.

• Extra rib: Some patients may have an extra rib that is located right above their first rib. This bone will impact the size of the thoracic outlet.
• Obesity and Poor Posture: Excess fat or a slumped posture can increase pressure on the joints, causing the passageway to narrow.
• Repetitive Activities: Overuse of the upper extremities can damage tissues and muscles in the thoracic outlet, causing it to shrink.


There are various symptoms that can occur in each patient depending on which nerves and blood vessels have been compressed. The ability to lift objects over the head and a patient’s range of motion will be difficult if the thoracic outlet has narrowed. Some symptoms may include:

Neck, arm and shoulder pain
• Weakness and easily fatigued shoulders, arms and hands
• Impaired circulation that may cause discoloration
• Numbness in the arms, hands and fingers
• Swelling and redness of the arms
• Cold arms, hands and fingers
• Blood clot in upper area of body


To determine if TOS is causing a your pain, your OSC Specialist will do a physical examination, and have you do a few simple exercises to test the upper extremities. X-rays may be taken of the thoracic region, and if necessary, an MRI (Magnetic Resonance Imaging) scan to see the thoracic outlet structures better. A nerve conduction study of EMG can be done to test how well the nerve is working and where exactly it is being compressed.


Most treatment methods for TOS are non-surgical. A physical therapy plan is often implemented to strengthen the upper body. If TOS has occurred because of extra weight, a weight loss program may be suggested. Some over-the-counter medications can be used to reduce the pain. If these methods are ineffective in relieving a patient’s symptoms, surgical options are available. A surgical procedure would involve removing part of the rib, or the extra rib if present, or rerouting nerves and blood vessels.