Thanks so much for your comments everyone. The new PT has me doing 15 simple shoulder shrugs 10 times a day, alongside wall push ups (20 each hour), and rowing with a theraband. And I'm not allowed to stretch anything! I've been doing the shrugs for 2 days now and my shoulders feel exhausted, and my left shoulder (less bad tos) has started crunching away like mad. Haven't done the other exercises yet as I'm scared! He also has me elevating my shoulders at all times by about 2 inches, so that my clavicles are at approx 30 degrees (they are normally horizontal or sloping down towards my shoulders). Am feeling quite tingly in my arms and hands, but not the deep achey pain that has me crying!
This new regime is so counter-intuitive to me I don't know what to do. One interesting thing that makes me think this new PT might have a point is that on my cervical spine MRI the scalenes on the right (bad tos side) were actually hypotrophied, as are my upper traps on that side. And then I went on madly stretching these weak muscles for 5 months!
It would be really interesting to hear more thoughts on shoulder elevation for treating tos, and for us to think that maybe, the model we read everywhere about stretching and releasing the scalenes might not be right for everyone...

Regarding my particular case - pain symptoms came on in December but I'd been having tingling and numbness in my hands for a while before that. At first I thought it was cervical radiculopathy as an mri showed up some disc bulges, but then the neuro didn't think they were pressing on nerves. I'm a massage therapist so I guessing having my arms outstretched contributed, my shoulders are rounded and droopy, my head is forward and I have a super straight cervical and thoracic spine. I keep getting told I'm hypermobile, and yet I can't get close to touching my toes with my hands since all this started as all my nerves and muscles feel incredibly tight. The thing that really throws me is that since Jan I've had the same tos-like pain in my right leg - down through the groin, front of thigh and into calf, and cold/numb toes at times. No one thinks I have a lumber disc problem. EMGs all normal, no cervical ribs. Most muscles in my body hurt to touch, and I'm now worrying I've developed some kind of central hypersensitivity (doc wants me to take amytriptiline but I'm currently tapering off paxil). And all this can be fixed with shoulder shrugs??