If you haven't had a recent MRI or xrays of the c spine it's a good thing even if just to rule out any other causes or anomalies of the bones or ligaments, some even do the T spine or upper T spine along with c spine.

somewhere I read a MRI is only as good as the tech reading the results... sooo...??
and what about a arms up vs arms down at sides??

I'm just guessing you have adhesions and "scar"' tissue in those old injured areas.
Generally most MDs, really don't study this stuff, but maybe you can get a good referral to an advanced PT person/place.
Hopefully a highly skilled & knowledgeable PT that will do some hands on work to loosen those adhesion & any possibly trigger points...

Might be a plus if you can locate some really good PT places then ask dr for the referral to one of them..
NO ROOKIE PTs allowed!! they usually just don't have the in depth knowledge or skills to treat TOS issues for the long run.

I went into some PT places and chatted w/ staff -when they weren't busy of course- but got some good info as well as what Drs might be best for what my issues were. *the dr info was after the fact for me.. but is a good thing to ask about.
I wish I thought of that in the beginning of my injury - the PT places probably do know who might be the best dr to try...


Also posture , posture posture....

but since you can relate back to the whiplash, there has to be some soft tissue problems happening , esp if the upcoming MRI shows nothing obvious going on.

Osteopath and/or physiatrist are my usual suggestions for starters, then maybe a neuro and or vascular if more in depth testing is needed.

But it is really amazing to me how much trouble & symptoms that sticky tissues, adhesions & trigger points can cause for us.

You might tactfully ask your dr about those things or if she knows of someone that does deal with these sort of issues.

MD or PT should do some of those positional/pulse arm tests - just good to have it verified - although a small % of normals have pulse loss also.

I don't have a formal dx by any MD, close to it but 2 PTs and DC agree it is TOS.
I responded to some really good PT and chiropractic as well as self care things I did at home - and started to see good improvements , although it took a couple years.. So I didn't need to focus on a dx anymore.

Sometimes looking for a dx, wastes time that can be spent working to fix the issues...
but basic tests to rule out any obvious causes or concerns is always a good thing...but usually soft tissue stuff won't show up on those kind of tests... that's where the knowledge of a expert PT comes into play, or a DC that has studied these things.