In thinking about the hips, extension and flexion, and different Sit positions, I thought about one of Lily's service dog behaviors, Visit. In Visit, Lily sits and then lifts her front paws onto my lap. She was taught to do this behavior because she maintains the weight of her body and can then rest her forelimbs almost weightlessly on my lap - for retrieving to hand, for resting her chin in my lap, for various husbandry chores that I can then perform while remaining seated myself.
Again, the behavior includes hip flexion. It includes extension of the forelimbs and extension of the cervical spine.
And then, Debbie, thinking of it from a purely hip extension POV, would the "dance with your dog" be the partner to this exercise? The extension to the flexion? Dancing is a great method of working the