Thanks for the posts. You're all very helpful

MP I will try what you have suggested (when it stops snowing LOL). Think it might help with pelvic angle as I have been wondering whether I'm sitting wrong - butt too tucked under perhaps.

Upper body I'm completely confused about because the position that feels relaxed and comfortable for the first half hour or so has me in agony by an hour, and at that point I don't seem able to find another position. I don't know if my posture starts out OK and then goes wrong and starts to hurt, or whether it's wrong from the beginning. Elbows always look slightly bent and relaxed when I remember to take note of them and hands and wrists don't hurt. Legs/knees/feet are all good too, just not strong enough Pretty sure I have the ear-muff shoulder issue though and physio seems to think I need to get the lower spine position sorted in order for the shoulders to sit where they should, which does make sense.

Anyone got a pic they don't mind sharing? If I could figure out a way to get a photo of myself in my normal riding position I would post it here for you all to critique.