More on travelling - altitude effects ? Driving & hands?

Spring break is coming up & we always travel to family some 14 hours away & come back via other family some 10 hours away. We usually break up the 14 hour drive with an overnight stay. Anyway, this trip takes us through a mountain pass.

Last year we made this trip in March and in August. Both times I was definitely in pain from sitting so long but I also found my hands, wrists, and elbows were excruciating !!! There was a point where I felt like they were being crushed. I tried Aleve and all I got was a very slight lessening of the pain for maybe half an hour. Ibuprofen doesn nothing.

So naturally I'm starting to dread this trip. I will take the suggestion of buying heating pads. Mtx is not working at all for me after 6 weeks so that'll be no help. Does driving make it worse ? I prefer to drive because it's boring being a passenger but honestly, I think holding the steering wheel may be the culprit - my hands/wrists/elbows stay still too long and gripping things hurts. However - does anyone know if altitude changes make a difference as well ? Does it work like barometric pressure ?