Secondly, in the helicopter, experiment with your seating position. Try setting the seat higher, lower. Seat tilted more backward or forward. Try the seat moved forward, then backward. I don't know if pedals are adjustable, but if they are try different pedal positions. Try changing your feet position on the pedals.
I spent most of my working life flying helicopters and in my experience most pilot seats only move backwards and forwards. If you find one with vertical adjustment you’re relatively lucky!
Yes, I do have a bad back….