--given your cycling hisotry, there should definitely be some investigation done in the areas of the lumbosacral spine and its attendant nerve roots, and along the cauda equina--the "peripheral end" of the spinal column.

There are so many places nerves to the sacral area and lower extremity can be compressed--in the spinla column itself, along the pelvic girdle, near the pubis, even along the upper part of the thigh structure--that a good series of imaging studies would make sense. Moreover, "double crush phenomenon" effects are very common in this area--a metabolic/autoimmune or other compromise to nerve that is not producing much in the way of symptoms is then exacerbated by mechanical compression along the nerve, with the result that the symptoms become greater than the sum of their component parts.

also problematic are ankle compression sites.

I have a bad left ankle, due to a surgery when I was 12 for a tumor, and then a terrible spider bite on it which swelled and hurt for over 3mos, and also a steroid injection into it.

Whenever I flex it too much...too often, it flares and that foot really hurts. I can only do 5min at a time on a recumbent bike, and have to rest. No more than 20 min total! (or I will pay a price).

I think you can get overuse in the ankles like you do in the hand, because of that tight ligament that holds it together. Just the slightest bit of pressure or fluid retention, and then you can have nerve compression.

Whenever I see a biker show up here with various symptoms, I have to wonder...bikes can be so problematic for some people.