Appybutt -- I'd call it a weak loin. The LS joint is beyond the point of hip, the back is long and the topline is weak (with age, I'm sure).

MiAmor -- that one will improve with conditioning. She is wasp waisted and her LS joint is behind her point of him, both of which are markers for a weak loin. BUT it won't look so bad (like SM's palomino paint) with proper weight and conditioning.