Just a note after some conversations about Pentecost Vespers and kneeling:
Worship is not meant to hurt you.
A healthy young person (or a lot of older folks who’ve done it all their lives) can stand on their knees for the whole fifteen minutes or so with minimal discomfort.
If it really, really hurts, then for goodness’ sake stand up. Just bow your head where you stand. Or if that’s a problem, find a pew or bench or folding chair.
Nobody is grading your performance.
Unashamed: I am between cortisone shots and my knees are not great right now; they’re okay for a while, and then NOPE. Today the rector did all the kneeling prayers while I sat down in the altar, bowed my head, and said my Amen. Nobody took notes, nobody was scandalized.
Do what you can and never apologize.