A few of the long time TOS {thoracic outlet syndrome} forum members have some spread of pain or symptoms to the lower body.

I have developed some low back /hip discomfort myself.
I think mine is myofascial related, but I haven't had any xray/imaging done for low back yet, so that may tell another story when I finally do.

I believe a few of the TOS docs do believe sx can sped to lower body, but some disagree also..

Have you had MRI or imaging to check out other possible causes?