You are likely right, but "prone" is the only opposite of "supine" I could think of. Perhaps "pronated" would have been better? The Latin "pronatus" refers to a bending forward position, which is what I was looking for, like a lion in the process of devouring a gazelle. Or a cyclist aggressively sprinting or climbing...

But you all are also right, I detect some thin-skinnedness here! Especially as evidenced by the remarks regarding the "prone" position, which I choose to take as good-natured ribbing, although it could also be interpreted as disparaging, were I thin-skinned or easily bullied.

L.