Blood work is not always reliable so if you still think that it may be rheumatological then try and get retested, there are various markers that certainly in this country they don't always look at unless specifically requested...ie. i think it is HLA B27 (something like that) that is a marker for AS.
Are there any other joint problems... , hips, Lumbar etc...may be worth (if you have not already) doing a general mobility screening.
Other things that I would look at are the neck and thoracic spine (T4 syndrome can give similar symptoms)...the symptoms are bilateral so maybe referred. Check pulses pre and post an upper limb activity..there maybe flow related problems.
Have they checked for diabetes...may be peripheral neuropathy related.
Lots to look and I am unsure how the system works where you are but if you can assess neck, thoracic, upper limb neural and blood flow and general whole body mobility screen and are still not happy definitely bounce back to doctors....there are so many random conditions that can cause symptoms like these.