TOS

Question 1

What is TOS?

Answer 1

Thoracic Outlet Syndrome is a condition caused by compression of the brachial plexus, subclavian artery, or subclavian vein as they pass through the thoracic outlet, a narrow space between the clavicle and first rib.

Question 2

What are the 3 types of TOS?

Answer 2

1. Neurogenic TOS (95%) – Compression of the brachial plexus, leading to numbness, tingling, and weakness in the arm and hand.
2. Venous TOS (4%) – Compression of the subclavian vein, causing swelling, cyanosis, and possible blood clot formation.
3. Arterial TOS (1%) – Compression of the subclavian artery, leading to coldness, pallor, and diminished pulses in the affected limb.

Question 3

What are the causes & risk factors TOS?

Answer 3

• Anatomical abnormalities (e.g., cervical rib, muscle hypertrophy)
• Poor posture (e.g., forward head position, rounded shoulders)
• Repetitive overhead activities (e.g., sports, jobs requiring arm elevation)
• Trauma (e.g., whiplash, clavicle fracture)

Question 4

Roo’s test

Answer 4

• Pt seated or standing
• Flex elbow at 90 degrees
• Open and close hands
• Repeat for 3 minutes
• Positive test = visible colour change, drop in shoulder, pain (sharp), pins and needles

This is testing for VASCULAR TOS (subclavian artery)

Question 5

Adson’s test

Answer 5

• Pt sits with neutral spine
• Extension of cervical spine (check radial pulse)
• Rotate towards affected side
• Abducting affected side shoulder (45 degrees)
• Extension of shoulder
• Externally rotate shoulder
• Check pulse again
• Positive test = reduced pulse

This is testing for VASCULAR TOS (tightness of scalenes causing compression of subclavian artery)

Question 6

Costoclavicular test

Answer 6

• Pt seated
• Retract shoulder
• Depress shoulder
• Check radial pulse
• Check at 40 degrees abduction and extension
• Positive test = diminished pulse

This is testing for VASCULAR TOS (clavicle and 1st rib compression of subclavian artery)

Question 7

Wright’s test

Answer 7

• Pt sitting
• Shoulder abducted to 90 degrees
• Elbow flexed 90 degrees
• Check radial pulse
• If not diminished next step….
• Abduction to 180 degrees
• Check radial pulse
• Positive test = diminished pulse

This is testing VASCULAR TOS (pec minor tight -compressing on subclavian artery)