If nerve compressions or adhesions are the cause of the atrophy strengthening is not going to change anything, i don't think...
I'm not 100% sure at all though , I just seemed to have sticky fascia causing most of my problems, so I don't know how an actual compression might react, we used to have a few posting about atrophy, but they haven't posted in a long time. 1 or 2 did have "clawing" of hand due to direct nerve affected.
The cause has to be addressed and then resolved as best as possible, then maybe strengthening, after pain & sx are mostly gone.
numb & tired fingers make me think of either c spine or TOS nerve sx - the nerve is being affected somewhere.
Or could be a blood flow issue.
Did anyone that seemed to have advanced training do a full evaluation before treating you?
Did they do a compression test -pressing down on your head and some tilting to see if it reproduced any sx?
traction - pulling/lifting your head and some tilting to see if any sx?
did they do the many positional blood flow testing shown on the nismat pages for TOS? I asked about these from one PT and he did do them after I asked about it.
Another PT that I found on my own (as a second opinion) already knew about them all and did them.
To me the place you are going to just sounds so different than the PT places I've been to.
But does sound like some of the places others have posted about.
I was lucky that each time I had to change PT places ( for wc /ins reasons & 1 time because I explained to the dr that the guy there was reading out of a book on how to do stuff
- Dr got me out of there fast LOL thank you dr.)
anyway each time I landed in a better place and I learned more along the way.
After awhile you can tell who is doing good work and who isn't.
Mine focused on
1- reduce pain - heat, massage, US,
2 - reduce symptoms - same as above
3 - start isometric exercises as tolerated
4 - start 1 lb weight as tolerated
5 - advance to machines & equipment for more strengthening as tolerated
after each step forward to more exercises - they asked and evaluated how I was responding - if sx or pain increased we took a step back
(now my chiro does US, IF stim & LLLT for me 1 visit a month usually)