Thoracic Outlet Syndrome

What is Thoracic Outlet Syndrome?

Thoracic outlet syndrome (TOS) refers to a group of conditions caused by compression of the neurovascular structures (the brachial plexus, subclavian artery and subclavian vein) as they pass through the thoracic outlet: the space between the collarbone and the first rib. Neurogenic TOS (compression of the brachial plexus) is by far the most common form. Arterial and venous TOS are rarer but more serious conditions requiring urgent vascular assessment.

Neurogenic TOS is frequently misdiagnosed or diagnosed late due to its variable and complex presentation. Symptoms can mimic carpal tunnel syndrome, cervical radiculopathy, rotator cuff pathology and other conditions. Specialist assessment is essential for accurate diagnosis and Hand Therapy is the primary treatment for most cases.

What causes Thoracic Outlet Syndrome?

• Postural factors: forward head posture and rounded shoulders narrowing the thoracic outlet
• Cervical rib: an accessory rib, present in approximately 0.5% of the population
• Hypertrophy of the neck muscles: common in overhead athletes and heavy lifters
• Repetitive overhead activities compressing the neurovascular structures
• Previous clavicle or first rib fracture causing callus formation within the thoracic outlet
• Prolonged carrying of heavy loads on the shoulder compressing the outlet

Signs & symptoms

• Pain, aching and heaviness in the shoulder, arm and hand. Often widespread and difficult to localise
• Finger numbness and tingling
• Symptoms provoked by overhead arm positions, sustained shoulder depression or prolonged computer use
• Weakness of grip
• Worsening of symptoms when carrying bags or heavy loads on the affected side
• In vascular TOS: arm swelling, colour change or a feeling of the arm 'going to sleep' rapidly

How Hand Therapy can help

Ms Razo provides specialist assessment and evidence-based treatment for Thoracic Outlet Syndrome. Following a thorough initial assessment, a personalised treatment plan will be developed to address your specific needs and goals.

Frequently asked questions

How is thoracic outlet syndrome diagnosed?

TOS is primarily a clinical diagnosis based on a detailed history and specific provocation tests. Imaging including chest X-ray (to identify a cervical rib), MRI and nerve conduction studies may be used to support the diagnosis and exclude other conditions. TOS is frequently misdiagnosed as carpal tunnel syndrome, cervical radiculopathy or shoulder pathology, making specialist assessment important.

Can thoracic outlet syndrome be treated without surgery?

The majority of neurogenic TOS cases are managed non-operatively with specialist Hand Therapy, postural correction and activity modification. Surgery (first rib resection or scalenectomy) is reserved for cases that have failed a thorough course of non-operative treatment. Vascular TOS involving arterial or venous compression typically requires earlier surgical consideration.

Is thoracic outlet syndrome related to carpal tunnel syndrome?

TOS and carpal tunnel syndrome can coexist as a double crush phenomenon, where compression of the nerve at one level (the thoracic outlet) increases its sensitivity to compression at another level (the carpal tunnel). Both conditions can cause hand numbness and tingling, but affect different nerve distributions and are distinguished by careful clinical assessment. If you have been treated for carpal tunnel syndrome without full resolution of symptoms, TOS should be considered.

How long does recovery from thoracic outlet syndrome take?

Recovery from neurogenic TOS with conservative management typically takes a number of months alongside consistent specialist Hand Therapy and home programme compliance. Postural habits accumulated over years take time to correct, and nerve sensitisation can be slow to resolve. Patience and commitment to the rehabilitation programme are important. Most patients achieve significant symptom improvement with thorough non-operative management.