Wow! I just came across two great visuals of what it's like when you have no heel foundation for your horse:
Here are some hoof pics so you can see what it looks like on the horse:
So what happens when you have no hoof foundation on your horse? Besides the horse being in pain from his tendons trying to hold himself up and his muscles straining to keep himself balanced, he will also move with a lack of cadence. In other words, the front feet will move faster than the hind feet, creating opportunity to forge or interfere.
Here's a visual of a horse at the trot. Notice how the inside and rear legs on opposite sides mirror each other. When I say lack of cadence, I mean that those legs don't mirror each other. Also notice how the horse lands heel or flat on his front hooves. That's a good side that his hoof is well balanced (although certainly not the only indicator).
Here's Buttercup actually landing heel/flat first!!!
We're getting there!