Disclaimer: This article is for general educational purposes only and does not constitute medical advice. Always consult a qualified health professional for advice specific to your condition. © 2026 Better Physiotherapy Bundoora.
Thoracic outlet syndrome is one of the most commonly missed diagnoses in musculoskeletal practice. It causes arm pain, numbness, and tingling that mimic cervical radiculopathy and carpal tunnel syndrome — but requires a different treatment approach.
What Is the Thoracic Outlet?
The thoracic outlet is a narrow space between the collarbone (clavicle) and the first rib, through which the brachial plexus (the major nerve bundle supplying the arm) and the subclavian blood vessels must pass. Several anatomical factors can compress these structures:
- Scalene triangle narrowing — tight scalene muscles reduce the space between the anterior and middle scalene through which the brachial plexus passes
- Costoclavicular space narrowing — forward shoulders and poor posture reduce the gap between the first rib and clavicle
- Pectoralis minor compression — tight pec minor compresses the brachial plexus against the coracoid process
- Cervical rib — an accessory rib arising from C7 narrows the thoracic outlet congenitally
Symptoms of Neurogenic TOS
Neurogenic TOS (nerve compression) accounts for over 95% of TOS cases:
- Arm pain, numbness, or tingling — often in the ulnar border (4th and 5th fingers)
- Symptoms worse with overhead activities, carrying, or prolonged computer work
- Neck and shoulder pain
- Weakness in hand grip or fine motor tasks
Physiotherapy Treatment
- Postural correction — addressing forward head posture and rounded shoulders that narrow the costoclavicular space
- Scalene flexibility — lateral neck stretches targeting the scalene triangle compression
- First rib mobilisation — direct mobilisation of the elevated first rib that is commonly found in TOS patients
- Pectoralis minor stretching — doorframe stretches and manual release to open the subcoracoid space
- Neural mobilisation — brachial plexus nerve gliding exercises to restore nerve mobility through the thoracic outlet
- Strengthening — lower trapezius, serratus anterior, and deep cervical flexor exercises to correct the posture driving the compression
Frequently Asked Questions
What are the symptoms of thoracic outlet syndrome?
Symptoms depend on which structure is compressed. Neurogenic TOS (nerve compression): pain, numbness, tingling, or weakness in the arm, hand, and fingers — often worsening with overhead activities or carrying. Venous TOS: arm swelling, heaviness, and blue discolouration. Arterial TOS: cold, pale hand and absent radial pulse. Neurogenic TOS is far more common than vascular types.
How is TOS diagnosed?
TOS diagnosis is clinical — based on history, symptoms, and physical examination provocative tests (Adson's test, Roos test, Wright test). Imaging (chest X-ray to rule out cervical rib, MRI for nerve compression) and nerve conduction studies help confirm the diagnosis. TOS is often misdiagnosed as cervical radiculopathy or carpal tunnel syndrome.
What does physiotherapy for TOS involve?
Physiotherapy targets the anatomical factors compressing the thoracic outlet: scalene stretching and relaxation (the scalene triangle is a common compression site), first rib mobilisation, pectoralis minor stretching, thoracic extension and postural correction, upper trapezius and deep cervical flexor strengthening, and neural mobilisation exercises.
When is surgery considered for TOS?
Surgery (first rib resection or scalenectomy) is considered when neurogenic TOS fails to respond to 3–6 months of quality physiotherapy, or for vascular TOS with arterial or venous compromise. Most neurogenic TOS cases are managed successfully without surgery.
Ashley Haleel
Physiotherapist & Owner — Better Physiotherapy Bundoora