Overview
Thoracic Outlet Syndrome (TOS) is a condition that occurs when the nerves or blood vessels in the space between your collarbone and your first rib (the thoracic outlet) become compressed. This compression can lead to pain, tingling, weakness, or changes in blood flow affecting the neck, shoulder, arm, and hand.
TOS can be frustrating and difficult to diagnose, as its symptoms often overlap with other musculoskeletal and nerve-related conditions. However, with the right assessment and an individualised treatment plan, many people experience significant improvement without the need for surgery.
At London Bridge Sports Medicine (LBSM), our team of sports medicine doctors, vascular consultants, and allied health specialists, such as Physios and sports nutritionists work together to help manage TOS using a conservative, evidence-based approach.
Anatomy
The thoracic outlet is a narrow space at the top of your chest, just behind your collarbone. This area contains important structures including:
- The brachial plexus – a network of nerves that control muscle movement and sensation in your arm and hand
- The subclavian artery and vein – major blood vessels that supply your arm
These structures pass through a confined space surrounded by muscles (especially the scalene and pectoralis minor), bones (the collarbone and first rib), and connective tissue. If this space becomes narrowed or restricted, it can compress the nerves or vessels, leading to a range of symptoms.
Types of TOS
TOS is usually classified into three types, depending on which structures are being compressed:
- Neurogenic TOS – the most common type, involving compression of the nerves
- Venous TOS – compression of the subclavian vein
- Arterial TOS – compression of the subclavian artery (least common but potentially more serious)
Most patients seen in sports and musculoskeletal clinics have neurogenic TOS, which is often postural, or activity related.
Mechanism of Injury
TOS may develop gradually or be triggered by a specific injury. Common causes or contributing factors include:
- Poor posture – especially prolonged slouched or forward-head posture
- Repetitive overhead activities – common in sports like swimming, throwing, tennis, and climbing
- Muscle imbalances or tightness around the shoulder and neck
- Anatomical variations, such as a cervical rib (an extra rib above the first rib)
- Previous trauma – such as whiplash or a fractured collarbone
- Heavy backpacks or tool belts used regularly
- Weight training with poor form, especially if focused on chest and shoulder muscles
The condition is more common in younger adults and athletes involved in upper body-dominant sports.
Symptoms of TOS
The symptoms of TOS can vary widely depending on which structures are compressed and the severity of the condition. Common symptoms include:
- Pain, aching, or discomfort in the front and side of the neck, collarbone area, and shoulder.
- Pain radiating into the arm, forearm, and hand
- Numbness or tingling in the fingers, hand, or forearm
- Weakness or heaviness in the affected arm, especially during overhead activity
- Coldness or colour changes in the hand (in vascular types of TOS)
- A feeling of tightness or pressure across the chest or shoulder
Symptoms often worsen with certain movements, such as reaching overhead, carrying bags, or prolonged sitting or typing.
Diagnosis and Assessment
Thoracic outlet syndrome can be challenging to diagnose, especially as symptoms may mimic conditions like cervical radiculopathy, rotator cuff problems, or carpal tunnel syndrome.
At LBSM, your assessment will begin with a detailed history of your symptoms and a physical examination by one of our sports medicine doctors or physiotherapists. This will include:
- Postural assessment
- Neurological testing (reflexes, sensation, strength)
- Orthopaedic tests to provoke or relieve symptoms
- Functional movement screening and activity review
Further investigations may be recommended to confirm the diagnosis or rule out other causes. These may include:
- Diagnostic ultrasound – to evaluate blood vessels and surrounding tissues
- MRI or MR angiography – in more complex or vascular cases
- Nerve conduction studies – to assess for nerve compression or irritation
Our clinicians will also assess lifestyle, sport-specific movements, workstation setup, and training habits that may be contributing to the problem.
Treatment Options
At LBSM, we believe in conservative, non-surgical management as the first line of treatment for TOS, especially neurogenic cases. Surgery is rarely needed and is typically only considered when conservative measures have failed.
Physiotherapy
Targeted physiotherapy is the cornerstone of treatment. Your programme will be tailored to your specific symptoms and may include:
- Postural re-education
- Stretching and release work for tight muscles such as the scalene and pectoralis minor
- Strengthening of the deep neck flexors, upper back, and rotator cuff muscles
- Nerve gliding techniques to reduce irritation and restore normal mobility
- Manual therapy
- Ergonomic advice for work and sport
- Gradual return to activity with improved movement patterns
At LBSM we work closely with our multidisciplinary team to guide your rehabilitation and track your progress.
Nutrition and Recovery Support
TOS is often linked with chronic muscle tension and fatigue, so addressing systemic inflammation and energy availability can support recovery. Our sports nutritionist can help you optimise your diet to:
- Reduce inflammatory load
- Improve tissue recovery
- Support energy levels and muscular function, especially if fatigue is a feature
Sports Medicine Management
Our sports medicine team may recommend additional treatments where appropriate, including:
- Dry needling or acupuncture for pain management and muscular tightness
- Ultrasound-guided injections – these are only used in selected cases – such as local anaesthetic and corticosteroid injections into the scalene or pectoralis minor muscles to reduce spasm and inflammation. These are used both diagnostically and therapeutically and are carried out with precision under imaging guidance.
- Botox Injections – Botox injections can be used particularly when muscle tightness is contributing to nerve or vascular compression. By injecting botulinum toxin into overactive muscles such as the scalene or pectoralis minor, the treatment helps to temporarily relax them, reduce pressure on the affected structures, and relieve symptoms like pain, tingling, and numbness.
Injections are typically only considered when physiotherapy and other conservative measures have not provided sufficient relief. They can also help identify patients who may benefit from surgical decompression.
In more persistent or complex cases, we can coordinate referrals to vascular or neurosurgical specialists as needed.
Outlook
The outlook for thoracic outlet syndrome is generally very good when diagnosed early and treated appropriately. Most people improve significantly with postural correction, physiotherapy, and activity modification.
Recovery time varies depending on the severity and duration of symptoms, but many patients begin to notice improvement within a few weeks, with full recovery typically taking several months.
At LBSM, we focus on long-term resolution by treating the root cause, not just the symptoms. Our multidisciplinary team will support you with a personalised treatment plan so that you can return to your sport, work, and daily activities safely and confidently.
If you’re experiencing unexplained arm or shoulder pain, tingling, or weakness – particularly during overhead movement or long periods of sitting – you don’t have to live with it.
The team at London Bridge Sports Medicine is here to help.
Get in touch to book an appointment or speak to a specialist.
