Under Pressure – Thoracic Outlet Syndrome

There are a lot of important structures between our neck and shoulders. We have nerves, blood vessels, muscles, and bones, all intertwined in this area behind our collarbone. When this area gets irritated, you can experience pain, numbness, and weakness in the shoulder and down the arm. We call this phenomenon Thoracic Outlet Syndrome (TOS). In this article, we will talk about what it is, and how to treat it.

What is Thoracic Outlet Syndrome?

The thoracic outlet is a passage for the nerves and blood vessels to travel into the arms from the neck. The clavicle (collarbone), the first rib, and the scalene muscles form a tight triangle around these nerves and vessels. Other muscles, such as the pectoralis minor muscle, compress these nerves and blood vessels as well.

Thoracic outlet syndrome happens when this passage becomes compressed in some way, which can happen for a number of reasons. First, some people have an extra rib at the top of their ribcage, which can push on this area. Second, large musculature or repetitive sport activities, seen in swimmers or weightlifters, can increase the pressure here. The opposite is also true: muscle weakness or poor posture can cause increased pressure to the thoracic outlet.

What are the symptoms?

The symptoms of TOS are usually some combination of pain, tingling, numbness, and in some cases swelling of the affected arm. These symptoms can be caused or made worse by certain positions or postures that put more pressure on the thoracic outlet, like a depressed and forward shoulder or poor neck posture.

Who is affected?

Thoracic outlet syndrome occurs in both athletic and non-athletic people. This condition is most common in women and in people with poor shoulder and neck muscle development. Swimmers and weightlifters who often have both increased muscle mass as well as poor posture can get TOS.

What else could this be?

Thoracic outlet syndrome is a common condition, but there are other potential causes of pain, tingling, numbness, and swelling in the upper extremity. Here are some other conditions that could mimic TOS:

• Nerve injury: Stretching or compressing the large bundle of nerves that passes through the thoracic outlet can cause similar pain and numbness. If treatment that would improve TOS symptoms does not help, we might suspect a nerve injury.
• Cervical spine injury: The thoracic outlet is not the only place where the nerves might be compressed – the neck is the most common area of compression of these nerves.
• Shoulder injury: Injury to tendons, ligaments, or nerves at the shoulder can cause pain in the arm similar to TOS.
• Pec minor dysfunction: The pec minor muscle lies on top of the bundle of nerves and blood vessels. If this muscle is tight or weak, it can mimic TOS.

Treatment for Thoracic Outlet Syndrome

If we suspect TOS, there are a few ways to improve the symptoms:

• Treat the source: Poor posture or muscle weakness can often cause TOS. If we can identify the source and restore normal function there, then the TOS symptoms should improve or disappear. Strengthening the postural muscles and avoiding positions that compress this area can help improve symptoms.
• Stretching pec minor: The pec minor muscle often contributes to these symptoms, if not causing them directly. Stretching and myofascial release of pec minor can improve symptoms.
• Taping: The scapula (shoulder blade) can be responsible for poor posture and compression of the thoracic outlet. Taping can help improve its position and relieve compression.

In some cases, especially where there is an abnormality like an extra rib or an old collarbone fracture, surgery might be needed to relieve the compression in the area.

Thoracic outlet syndrome can be a debilitating condition, but is often quick to fix! If your symptoms match up with what we’ve discussed here, book an appointment with us today to get this under control!