towelhorse,

It makes a lot of sense. I agree the head forward posture is an attempt to relieve the pain and pressure on the b.p., I never noticed it prior to my injury.
My TOS was a result of acute trauma (vaccine reaction), but I was pre-disposed by my body - short, so I've spent my entire life reaching above my head, thin, narrow chest and long neck, plus an "extra" scalene, scalene minimus, draped all over the brachial plexus and extra tight under the subclavian vein.

One of the first noticeable sx was a drooping right shoulder - the long thoracic nerve was affected, weakening the serratus anterior muscle dramatically. I've always felt if there was a way to lift the shoulder back to it's proper position, the nerve compression would be resolved. But other than strengthening exercises, which have only made me much worse, I haven't been able to figure out how to accomplish that. I have, at a neuro's suggestion, trained myself to carry that shoulder level with the left, but this in turn creates issues with muscle fatigue and additional trigger spots - but it does relieve the pain of the shoulder girdle's weight resting on the plexus. When I'm seated or in bed I try to relax the arm and prop it on pillows. It's sort of a Catch-22 situation.

One thing to remember early on in the process is when there are scalene muscle spasms, you are also going to get brachial plexus involvement (TOS) - you may not feel it that soon or see the symptoms as it can take a while to develop, but if the scalenes are irritated then the nerves of the brachial plexus will be affected as they pass among them (they should "glide" freely).
Sensory nerves are affected sooner than motor nerves.

Thanks for sharing - got me thinking!
beth