A few days back I posted a question [I am making a sentence presenting the image in picture. I want to say that one shouldn't sit the way that the knees are wide open. Does this construction suits best? Note the bottom of the man should be resting on the floor, it's not in the image though.] Actually I couldn't find the exact image that time. That image didn't present the exact position of knees, thighs and bottom. I am posting another image that actually I wanted to ask about.
Can I say:
Don't sit with your legs pointed up.
Don't sit with your knees pointed up.
What would be the best sentence for this?
What I want the sitter to do is that they sit in a way that their bottom and thighs don't come into view. It is about the exercise in which there is a particular step in which one has to sit in a way that knees are pointed up but not so wide that bottom and thighs are seen.