Ergot.
It is very similar to the chestnuts on a horses leg, and they have no nerve endings. they can be cut off and the horse will not feel it.
The area above a horse's hind hoof is called the fetlock joint. It acts as a hinge to allow movement in the horse's lower leg.
The fetlock is the joint on a horse's leg located between the long pastern and the cannon bone, similar to the ankle on a human. It provides flexibility and helps absorb shock when the horse is moving. Injuries to the fetlock can be common in horses involved in athletic activities.
this long bone that runs from the hock to the fetlock is called the cannon bone
The bone in a horse's leg that runs from the knee to the fetlock.
if the injury is completely healed and isn't causing the horse any pain the yes horses can still jump after a fetlock injury.
The horse is built for speed, and its muscles are bunched at the top of its legs. The horse's knee is called the stifle and is only slightly below the 'body' level. The hock, less than halfway down the leg, corresponds to the human ankle. From the hock to the fetlock, the bones that correspond to those in the human foot are fused. The fetlock is the first toe joint - the horse stands on the tip of a single toe.
All horses have a ergot on the rear of their fetlock.I include this link as you don't state where on the fetlock. (see link)
On a horse's leg, the fetlock is a hinge joint relative to a human's knuckle. It is colloquially known even by experts as an ankle, but according to the related link below, that is a misnomer. Please see the link:
It is the first joint above the hoof.
there are many. fetlock,forlock,barrel,hoof,frog,ect.
the pastern
the fetlock is the horses ankle joint, it's the big round joint at the end of the horses leg right above the pastern and hoof.