Can I say;
Keep your neck in a position that is curved forward.
Instead of
Keep your neck in a position in which it is curved forward.
In the first sentence it sounds “that” suggests that the position itself is curved, not the neck but what I couldn’t understand is that when we say “in a curved position” “curved” modifies “position” it means position itself curved and in my phrase” in a position that is curved” “curved” modifies “position” in the same way. I couldn’t understand why we can’t say in a position that is curved while saying in a curved position.