The worst seat was the Gazelle which didn't support the back of your legs very well leading to problems for some people with sciatica and lower back pain. I only ever flew short sorties in it due to being in a training environment but you certainly knew about it after a long navex.
Myra is correct re 'george' not being much use when precision hovering is required, especially with one of your mates on a 200 plus length of winch wire.
Many more recent ex-mil pilots have neck problems due to the widespread use of NVG/NVD.
The fact is that getting old is !!!!! but its better than the alternative. You don't know what issues you would have had if you hadn't spent your life in a helicopter - my BIL had lots of back and sciatica problems and he was a desk jockey for all his career.