Things to try-
we all have various causes & factors so it may or may not help , but might be worth gently testing these.
* slow & easy works better than going all out and then backwards.. due to the delayed pain factor*
Sharon Butler's website explains why gentle stretching is better than hard core forcing stretches.. I found the info very helpful.
Repetitive Strain Injury Self Care

https://www.neurotalk.org/members/100-albums422.html
I spent a lot of time on a soft rolled up towel then got a foam roller & large exercise ball - they all worked for me..

Trigger point work- we have a sticky thread about it..
Top rib mobilization - was a big plus for me --a forum search or web search will find info on it

My version of TOS was due to work postures 15 yrs, past whiplash, past shoulder injuries, plus hyper mobility.. mainly soft tissue based.

Thanks for the info.

I did the roo's test with my PT and couldn't last more than a minute.... and when I'm trying to do the doorway stretches to open up my pecs.... I started feeling the heaviness and fatigue in less than 20 seconds...... my PT told me not to over exert myself, were u guys in the same boat? Its kind of frustrating when I can't even do the stretches properly to help my symptoms, did you have the same issues because I tried your stretches and they are much more doable and less strenuous.

When I raised my arms up for most of the doorway stretches.. the blood drained out of them.. still does, but I can manage it if I need to hold things up for a short time without symptoms coming back.
But it is not the right thing for me..

Many PTs are programed to do the generic treatment plans..
TOS needs a more advanced & personal approach, communication & adjusting the plan for you and your symptoms.

I had the best help with a very good chiropractor & also PT professor that also had his own clinic.. Plus consistent home work.. and a big reduction of activities that increased symptoms..

Medical providers can only do so much unless surgical or RX'd meds are needed.. much is a lot of self work at home..

I don't do the doorway versions of the pec minor stretches. I do the floor based ones:

"Lie flat": Lie on your back with legs bent, one arm overhead. Anchor the hand of that arm with something like a book or weighted ball. Let legs drop away from that arm. Feel the stretch. Reference: 9.1 Chest Pectoralis Major & Minor Stretch - YouTube

"Half foam roller": Once the above is comfortable, lie on a half foam roller and do the same stretch though you won't likely need the weight on your hand. You can also stretch out to the side for a chest stretch. I use the half roller "OPTP PRO-Roller Soft Density Foam Roller" at Robot Check

"Full foam roller": Once the above is comfortable, you could possible go to a full foam roller.

"Swiss ball": Once the above is comfortable, you could use a swiss ball.

I'm still on the half foam roller after my pec minor syndrome flared up on me after neglecting to stretch it for months.

Have any of you been able to find a position or know of a certain med that will get rid of the sensation of your arms feeling "heavy" and about to go numb.... I've been trying different positions, but none have worked and even advil pm doesn't help take that sensation away so I'm having a hard time sleeping at night.....

The heaviness for me was due to lack of blood flow , lack of coordination followed if I continued the activity.

Ongoing heaviness , swelling & blue or mottled color changes in arms can be Venous TOS related..

In the past some had both NTOS & VTOS & Pec minor syndrome, or other combination of factors..
Like scalene issues, Extra C rib, large transverse process, large neck muscles or larger than normal bones..
A tricky process to figure out all of it.. if you can find out & work on the worst symptoms, the rest might follow.

The only thing that ever worked for me was stretching my pec minor daily and shoving my first rib down.

Well that and being so exhausted, I passed out.

Some people, including myself, have also slept fairly upright in recliners, with or without pillows under the arms.

HTH

Hi nickO and others, Sleeping on your back, or sides can make the pain in your arms much worse and prevent sleep. What has helped my symptoms, which are in both shoulders and arms, is sleeping on my back with both shoulders propped forward and a little bit up towards my head. I do this with a pillow that extends down under my shoulders, not just supporting my neck and head. If I fall off the pillow, my symptoms recur. If I prop them back up, they resolve. I also make sure my neck is slightly flexed by the pillow being tall enough or second narrow pillow under the very top of my head. All of this positioning makes the scalene neck muscles and the pectoralis minor muscle less taut. Hope it helps you sleep!