This is a case of an aged  miniature horse with severe, lifetime foot deformity that had not been trimmed in a long time. 
It was unable to walk comfortably because the hoof "capsule" (the hoof wall  bars and and sole) was so bent that when it rolled over to the inside, twisting the entire fetlock and pastern sideways. The goal was to find the "real"  bottom of the foot under the coffin bone by finding and following the live sole . The sole is a good guide to levelling  the bottom of the coffin bone, the base that the horse should be standing on . This will create a flat platform for the horse to stand on. This foot was always going to tend to grow this way because the bones were deformed, but we got him a lot more comfortable with regular trimming. He eventually died  of old age complications (severe cushings disease and arthritis) after about a year and a half of at least  being more comfortable with proper trimming .

This is the finished trim ,  the first visit from a farrier for this little guy in a long time.
He was now able to walk more comfortable because the foot no longer tipped over sideways as he loaded it. Something for student trimmers and farriers to note is that the longest side,needing the most trimming from the bottom  was the inside. Although it looked lower from the front, the hoofwall on that side had folded over and therefore can seem to be the short side. In fact it is the longst side, which needed the most trimming from the bottom .