When I purchased my baby, I was told by the breeder, he is a straight back GSD. Realizing there are many types but never heard that term before, I accepted it. I know you've had many forums from me complaining about his behavior, and how I'm at my wits end well... upon looking it up on the net, I found out my little GSD is not a GSD but a Belgian Malinois, in the GSD family but built for strength, and speed. I took my little angel out in a field in early February and he ran 50 feet ahead of me, stopped, turned around and made a bullet run right into me, and used me as a bowling pin. Good thing i'm not old enough yet for broken bones etc... he is extremely fast and needs the running space, we take him through the bushes allot and he will jump over ravines and jump through ponds. He looks like a miniature deer when he jumps. He is now 16 months old and on his hind legs, he can easily put his front paws on my shoulders for kisses.
A Belgian Malinois has a massive chest and a very tiny waste for speed and strength, they are the #1 Law enforcement dogs, recue, search, drug dogs, because they can get into the tiniest places with ease.