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What is Thoracic Outlet Syndrome?


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Thoracic outlet syndrome is a painful condition in which swelling of the thoracic outlet can compress the nerve and blood vessel bundles that stretch from your neck to your fingers.

The thoracic outlet is a space between your collarbone and your first rib (see diagram below), just in from the top of your arm bone. Thoracic outlet syndrome arises when the nerves and blood vessels in this space become compressed or “impinged.”

You can develop thoracic outlet syndrome, or TOS, through sports- or work-related repetitive motions or after suffering from a traumatic accident such as a traffic collision. There are several different ways in which doctors and therapists can help you to ease the pain caused by TOS.

My experience

I have worked on tens of clients with diagnoses of thoracic outlet, or who have TOS-like symptoms.

On assessment, we often find that there is a hypertonic (“tight”), overactive pectoralis minor muscle (see diagram above), and potentially also tight pectoralis major, subclavius, and anterior deltoid muscles.

When these muscles round or pull forward the shoulder, they also pull on the ligaments that connect the shoulder to the collarbone. This can pull the collarbone down directly onto the blood vessels and nerves that travel beneath, compressing and impinging them between the collarbone and the upper ribs.

So we have the collarbone being pulled downwards onto the uppermost ribs.

Then, to make this pattern worse, we very often find hypertonic scalene muscles in the neck area (see the 3D pic above). These muscles pull the ribs upwards, moving them further into opposition with the collarbone.

The result of all this muscle tightness

So, with the ribs being pulled up, and the collarbone being pulled down, the thoracic outlet space closes and this compresses the bundle of nerves and blood vessels passing through.

When blood flow is decreased, there is often a sensation of cold, tingling, or numbness down the arm and into the hand.

If nerves are compressed, often the first three fingers of the hand might feel a numb or tingling pain. Pain can also occur anywhere else between the neck and hand. Sometimes grip strength or the ability to feel something you are holding decreases, or it might be difficult to type, write with a pen, or use tools.

For neurogenic (nerve-related) TOS there can be severe muscle wasting at the base of the thumb, called “Gilliatt-Sumner hand.”

Types of Thoracic Outlet Syndrome

There are two main types of thoracic outlet syndrome, and one type that is still up for debate.

  1. If the swelling affects your nerves, it is called neurogenic or neurological TOS.
  2. If it affects your blood vessels, it is vascular TOS.
  3. (?) When there is no discernible cause, yet still pain in that area, it is nonspecific TOS.

While some experts do not believe that nonspecific TOS is a true condition, others argue that it is very common.

How does TOS happen?

Thoracic outlet syndrome happens when the superior thoracic outlet is compressed. This outlet is a neurovascular bundle that passes between the anterior and middle scalene muscles at the base of the neck and then onwards between the collarbone and first two ribs.

TOS is more common in women than in men and between the ages of 20 to 50.

The most common cause of thoracic outlet syndrome is trauma, which can be sudden or repetitive.

With sudden trauma, such as a direct blow to the collarbone or a fall on an outstretched hand (FOOSH injury) there may be a fracture in the clavicle.

Repetitive trauma, on the other hand, happens when you have to do the same tasks over and over again using the wrist and the arms, especially when your arms are out in front of you for long periods. Examples are truck drivers, factory workers, chefs, or typists. (Even massage therapists have to be careful!)

Those who are at risk for developing TOS are people who are in non-ergonomic postures for several hours working on computers, and, those who often have to raise their arms for overhead tasks, such as athletes, electricians, musicians and rock climbers.

Conventional approaches to treatment of TOS

For most people with TOS conventional doctors will start you with a conservative treatment program. This involves physical therapy, abstaining from or reducing causative activities, relaxation techniques, and anti-inflammatory medication such as ibuprofen. You might also be prescribed muscle relaxants.

Outcomes can vary. If these treatments do not alleviate your suffering, doctors may recommend more invasive methods. For vascular thoracic outlet syndrome, you could have surgery with an anterior supraclavicular approach. A surgeon makes a cut just under your neck and then examines you for signs of trauma. The surgeon may repair blood vessels or remove any fibrous bands that may be interfering with your circulation.

Another surgical method is the trans-axillary approach. Here, the incision is closer to your chest so that the surgeon can cut out any portion of your rib that is compressing your nerves or blood vessels. If you have advanced thoracic outlet syndrome, your road to recovery may be very long and painful, as well as costly.

Keeping in mind that I am not a surgeon, and have no specialist medical training, it is my strong opinion that this type of rib removal surgery is barbaric and unnecessary.

Rib removal surgery has become uncommon today, but some older surgeons may still recommend it. In such a case, I recommend getting a second opinion.

My approach to treatment of thoracic outlet syndrome

To help the problem, I believe the key is to create more space and a larger opening of the thoracic outlet area to take the pressure off the nerves and blood vessels.

In most cases, relaxing the pec-major, subclavius, anterior deltoid, and especially the pec-minor and scalene muscles, is fundamental to lifting the collarbone and shoulder bones and allowing the upper two ribs to drop down, thus decompressing the thoracic outlet.

Other neck and shoulder muscles may also be involved, so it may take several treatments to resolve the condition.

Myotherapists, osteopaths, chiropractors, physiotherapists, and remedial therapists like me have the training to assess and treat thoracic outlet syndrome. Your therapist can examine the area to find which bones are misaligned or moving improperly.

In the following video I go through an assessment sequence that investigates the entire nerve chain (in this case the median nerve, which is common in carpal tunnel syndrome) from the neck to the hand, including the thoracic outlet, to find out exactly where sites of compression exist:

Poor posture is involved with a majority of people suffering from thoracic outlet syndrome. Complications with breathing are also common. Therapeutic exercises to improve breathing, posture, and mobility of the upper body are therefore essential to recovery.

Stretching and nerve gliding

Stretching is also essential to relieving TOS, but must done properly. This is intended to help reduce the compression of the thoracic cavity, decrease impingement of the blood vessels and nerves, and realign the muscles, bones, and ligaments that can cause thoracic outlet syndrome.

Nerve gliding is also an effective treatment method for TOS, and I show you how to do this in treatment. You extend the affected arm out to the side and tilt your head to the opposite side. You’ll feel a gentle, vaguely painful pull on the affected side when you do this. Hold for a very brief second, then come back to neutral posture. We repeat this ten times in succession.

Following nerve gliding you should feel at least a temporary reduction in your symptoms.


This article is meant to be advisory only and is not a method of diagnosis, assessment, or treatment prescription of thoracic outlet syndrome or any physical condition. If you suspect you may have symptoms such as those outlined above, GO SEE A PROFESSIONAL and get assessed!

There is NO substitute for trained, hands-on assessment for any physical condition or disfunction.

If you have any questions about my thoughts, opinions or experiences regarding thoracic outlet or similar conditions, head across to my Facebook page and post a comment, or send me a tweet on Twitter.

Or, if you would like a comprehensive assessment by me, click the link below and book yourself in for an appointment. I’ll be very glad to help however I can.