Thoracic Outlet Syndrome (TOS)

Who: Repetitive overhead activity, carrying, trauma, or a long history of postural loading. Overhead athletes specifically.
What: Compression of the neurovascular bundle at the thoracic outlet. Three syndromes share the name.
How it behaves: Pain and paraesthesia — neck, shoulder, arm, hand. Aggs: overhead activity, carrying loads, sustained postures. May describe swelling, heaviness, a cold hand.

Three syndromes, one name

The one thing to take from this page:

This is a diagnosis of exclusion. Clear the cervical spine and the distal entrapments first, and take the vascular history every single time — because patients may describe a swollen, heavy, cold hand, and two of the three syndromes that share this name need medical review before any rehabilitation.

Five stages, in your course's order.

MAIN PROBLEM

"My arm goes dead when I work above my head."
"Carrying the shopping sets it off."
"My hand feels heavy and clumsy by the end of the day."

BODY CHART

Chart interpretation: Neurogenic symptoms, possible venous thrombosis and possible arterial ischaemia need separate interpretation. Atypical means atypical for routine musculoskeletal rehabilitation, not necessarily atypical for that vascular subtype.

• Neck, shoulder girdle, down the arm, into the hand. Map it and mark P1.
• Ask which fingers. A C8/T1 distribution — ulnar border, ring and little finger — is the classic nTOS pattern and it is not the classic carpal tunnel pattern.
• Mark colour, temperature and swelling changes on the chart. Most students never do. On this pattern it changes the disposition.

BEHAVIOUR

• Aggs: overhead activity, carrying loads, sustained postures, prolonged driving, sleeping with the arm overhead.
• Eases: lowering the arm, unloading the shoulder girdle, rest.
• 24-hr pattern: builds with overhead activity and carrying loads, settles when the arm comes down.
• Night: sleeping with the arm overhead is in the Aggs. Night pain with weight loss, fever or a lower-trunk pattern is the §4 flag.
• Severity: VAS 0–10 at best / at worst / right now.
• The position, not the movement, is usually the aggravator. Ask how long they can hold the arm up before it starts.
• Irritability: resting symptoms + vigour of the provoking position + time to settle. Time-to-settle after overhead work is your best asterisk here.

HISTORY

• Repetitive overhead activity — occupational or sporting. Read further: TOS in sport [1].
• Trauma — including cervical or clavicular injury.
• Postural loading, a long desk or driving history.
• Any previous neck imaging? Ask whether a cervical rib was ever mentioned.
• Progression — is the hand getting weaker or clumsier?

SPECIAL / SCREENING QUESTIONS — do not skip these

• Has the arm ever swollen, gone blue or purple, or felt heavy after effort? → venous.
• Does the hand go cold, white or blotchy? → arterial.
• Any sudden change?
• Any night pain, weight loss, fever, or smoking history with a new neck or shoulder symptom? — the apical lung.
• Any dropping of objects, wasting, or loss of dexterity?

On this pattern the ranking is not a formality — it is the diagnosis. TOS is defined by what you have excluded.

The ones that outrank the table

• Venous TOS (effort thrombosis). Swollen, heavy, discoloured arm. Not a rehab problem.
• Arterial TOS. Cold, pale, diminished pulse, distal ischaemic changes. Medical review first. Acute limb ischaemia is an emergency; outside that, management typically begins conservatively, with physical therapy, after the medical work-up (Huang et al. 2021) [21].
• Apical lung pathology. Smoking history, night pain, weight loss, a lower-trunk pattern.

One anatomical factor to ask about

Cervical rib. Read further: cervical rib prevalence and its association with TOS [2]. The practical point is that this is not purely a postural condition, and asking whether previous imaging ever mentioned an extra rib is a free question.