To me, it just confirms that the predisposition is not that rare, which makes sense as the thoracic outlet is such a narrow passage for all those structures to pass through in the first place, in an anatomically "normal" human. But how did they first decide what anatomically normal WAS anyway?
Case in point, the disagreement over how many people today are born with a scalene minimus, no longer useful but thought to be a carry-over from when we walked on all fours?

Is it accurate to call all of these anomalies (or abnormalies - Lisa, I like that term!) - or are the most common ones just variations, with some variations more susceptible to injury? Or maybe a better way to put it, less likely to bounce back from stress and/or injury?

I had an extra scalene but no pain or parasthesia for 41 years til injured. When Dr A. removed it, it was wrapped all over and around the plexus, and ran tight up beneath the vein, causing pain with every movement of my arm.
Even though the sc. minimus ran such an awkward course, without the injury I would have been completely unaware of it - and TOS!

Alison, could you please make that a nickel? Pennies are just so annoying!

beth