What is the thoracic outlet?

The thoracic outlet is a passageway located at the top of your ribcage, between your collarbone (clavicle) and your first rib. Within this space, important structures pass through or around it, including nerves, blood vessels, and muscles. The brachial plexus, a network of nerves that controls the muscles of the arm and provides sensation, passes through the thoracic outlet. The subclavian artery and vein, which supply blood to and return blood from the arm, also traverse this space.

What is thoracic outlet syndrome (TOS)?

Thoracic outlet syndrome (TOS) occurs when there is compression of the nerves and/or blood vessels in the thoracic outlet. Neurogenic TOS is the most common type, involving compression of the brachial plexus (nerves) as they exit the neck and travel down the arm. Vascular TOS is less common and involves compression of blood vessels (subclavian artery or vein) leading to decreased blood flow. This compression can lead to symptoms like pain, numbness, tingling, and weakness in the arm and hand. Many practitioners will also include nerve or blood supply issues stemming from a passageway above the costoclavicular space within the TOS framework. The muscles making up this corridor are the scalene muscles.

What causes thoracic outlet syndrome?

Various factors can contribute to the compression of nerves and blood vessels in he thoracic outlet, including:

• Anatomical Variations: Individuals with certain anatomical variations, such as an extra rib (cervical rib) or an abnormal first rib, may be more prone to TOS.

• Poor Posture: Prolonged or poor posture can contribute to compression in the thoracic outlet.

• Repetitive Movements: Activities that involve repetitive arm motions or overhead movements, such as typing, carrying heavy loads, or working with arms raised, can contribute to muscle imbalances and compression.

• Trauma or Injury: Trauma, such as a car accident or a fall, can lead to injuries that contribute to TOS.

• Muscle Imbalances: Tightness or weakness in the muscles surrounding the thoracic outlet can lead to compression. Imbalances between the chest and back muscles can contribute to this condition.

• Obesity: Excess weight can contribute to compression of the thoracic outlet.

• Pregnancy: Changes in posture and increased pressure on the blood vessels can occur during pregnancy, potentially contributing to TOS in some cases.

• Tumors or Abnormal Growths: Tumors or abnormal growths in the thoracic outlet region can compress nerves and blood vessels, leading to TOS.

What are symptoms of thoracic outlet syndrome?

Symptoms can vary based on the type of TOS but may include pain, numbness, tingling, and weakness in the arm, shoulder, or hand. Vascular TOS may present with symptoms like swelling, discoloration, or coldness in the affected arm.

How do you treat thoracic outlet syndrome?

The approach may vary depending on the type of TOS (neurogenic or vascular) and the underlying causes. Some common treatment strategies used by the practitioners at Mountain Health and Performance include:

• Exercises/Rehab: Improving posture, strengthening muscles, and addressing muscle imbalances can be beneficial. Stretches may also be included.

• Ergonomic Changes: Modifying workstations and daily activities to reduce strain on the affected region.

• Activity Modification: Identifying and avoiding activities or positions that worsen symptoms.

• Manual Therapy: Soft tissue mobilization, myofascial release, and joint mobilization/manipulation may be used to address muscle tightness/joint stiffness and improve mobility.

• Nerve Gliding Exercises: Specific exercises to promote nerve mobility and reduce compression.

The choice of treatment depends on the severity of symptoms, the underlying causes, and individual factors. For rare cases that are resistant to conservative measures, surgical consultation may been deemed necessary.