4 doctors weighed in:
Whats thoracic outlet syndrome?
4 doctors weighed in

1 doctor agrees
In brief: TOS
Tos involves the lower portion of the brachial plexus, where nerves from the neck pass through a tunnel into the chest on the way to the arm. The plexus can get trapped in the outlet area, and this event can cause pain, numbness, tingling, weakness, but can also affect blood vessels.
On occasion, a congenital first rib can cause compression but trauma may also promote tos.

In brief: TOS
Tos involves the lower portion of the brachial plexus, where nerves from the neck pass through a tunnel into the chest on the way to the arm. The plexus can get trapped in the outlet area, and this event can cause pain, numbness, tingling, weakness, but can also affect blood vessels.
On occasion, a congenital first rib can cause compression but trauma may also promote tos.
Dr. Bennett Machanic
Dr. Bennett Machanic
Thank
2 comments
Dr. Gabriel Goren
an other reason for TOS is scalenus anticus syndrome a muscle that will pull the first rib up and against the collar bone compressing nerves of the brachial plexus, axillary vein and artery...
Dr. Laurence Badgley
It seems to me that shoulder, clavicle, elevation via superior trapezius contraction is dynamically superior to scalene contraction & elevation of the first rib; which I have been led to believe is a theoretical construct; perhaps explaining the poor outcomes of scalene release. Is there clinical/anatomical evidence for scalenus anticus syndrome?
Read more answers from doctors