Just some thoughts which might be relevant:
Paper filled cockpits; ie regular twisting >90degrees downwards, to pickup heavy Jeppie chart folders, Tech Logs etc while having to remain strapped into a fixed seat.
I know of one airline where pilots were warned to be aware of this after several back problems.
Will problems decrease with EFB's/iPads, where relevant documents are forward of the seatback line ??
I reckon this is not a factor from office staff with free, movable, swivel seats.
Aircraft specific vibrations; I am not a medic but what is the long term effect of vertical, high amplitude vibrations on the spinal discs?? (not to mention the odd "cruncher").