sorry I can't think of a better way to phrase this question.
I have been working on a horse walk animation for quite awhile now. I am pretty inexperienced with rigging and animation in general, but I am quite familiar and comfortable with Blender as a whole.
Following various image references & video tutorials I have the horse legs working in the way I want.
Now to make Horse really shine, I want to animate his spine bouncing with him. Following this reference image I can see the stages where his spine should move to certain places, but my rig doesn't transform the way I need it to.
The biggest issue is when I try to make his butt go down, it makes the whole front half of him shoot straight up into space.
I've tried to re-rig it quite a few times, but I am getting the feeling that I am missing something to make it work the way I need. Is it possible I need to use an IK Constraint from the Back to front? I haven't seen anyone use a method like that, but I am very confused on how to approach this problem.