Noel
This is what I did. I bought a sheep skin pad for my National 425 that goes between my back and the chute. I using adhesive velcro tape, I velcroed' a small lumbar support cushion to the back of the chute container, and velcroed' an inflatable lumbar support bladder to the back of the sheepskin. The lumbar support bladder has a hose that runs up the shoulder strap and ends with a squeeze bulb similar to a blood pressure cuff. Usually the lumbar support cushion is enough, on long flights, a little inflation on the bladder makes life good again.

Example of a inflatable lumbar support
http://www.sportsimportsltd.com/inseluinairc.html

Example of a small lumbar support cushion
https://www.bedbathandbeyond.com/sto...vel/1014256946

Sheepskin for parachute
http://wingsandwheels.com/parachute/...pskin-pad.html



SF