Similar to the "building neck muscle" thread, I would like some suggestions on how to build up my geldings shoulder muscles and his topline. He's an 11 year old TB off the track, and from my understanding they normally have lots of front-end propulsion, so their shoulders/chest muscles are generally bigger than their back end. Well as of right now, he still has excellent condition in his hind, but I can easily stick my fingers behind his scalpula...where his neck and chest come together is basically just skin. If I can get his shoulders a little more conditioned I also want to work on filling out his withers and topline, which although they aren't horrible could use some work.
So, suggestions? I ride Western, in a hackamore, and he generally doesn't lunge very well.