13/10/2026
She’s standing at his quarters with her hand flat on the top of his croup, asking whether that bump is something I can put back.
For a long time my answer would have been about the bump itself: the point of the croup sitting too high, and the sacroiliac area I’d treat around it.
The bump is a pronounced tuber sacrale, the top of each half of the pelvis standing higher than it should. We’re usually taught that in a well-set croup the tuber sacrales sit level with the line running from the lumbar spine back over the sacrum, so the top of the hind end looks smooth and round. But what are we comparing each pelvis to? Breed, age and build all change how prominent the tuber sacrales are, so a croup that looks high on a Quarter Horse can be completely normal for a Thoroughbred, and an older horse that has lost topline will show more bone than a young one in work. Before we call it a hunter’s bump, we need to know what normal looks like for this horse.
When it isn’t just this horse’s normal, what changes that line is how the pelvis is held together. The sacrum isn’t joined to the pelvis by bone. It sits between the two halves, held there by strong sacroiliac ligaments, and the pelvis doesn’t become a stable ring until the p***c symphysis fuses at around five or six years old. If the pelvis is loaded hard and often before then, through jumping, starting stalls or fast repetitive work, the two halves can slowly draw inwards on the sacrum. The lumbar spine and sacrum drop, and the tuber sacrales are left standing proud.
So the bump isn’t a lump that has appeared. It’s the part we can still see once everything around it has sunk.
Plenty of these horses still do their jobs, and nobody did anything wrong by riding a horse that looked sound. What the bump does tell us is that the sacroiliac region is working out of its ideal position, and that the pelvis has been coping with load from the hind limbs and the spine for a long time.
What I tell owners now is this: “The bump is the top of his pelvis standing out because the area around it has dropped. We can’t flatten it, but we can find out what it’s been compensating for and take some of that load off.”
That’s the systems view of the pelvis that Bradley Whale and I are teaching this month, and it changes our question from “how do we flatten this?” to “what has this pelvis been holding up, and is it still managing?”
A hunter’s bump isn’t where the problem starts. It’s where the horse’s history shows.
PS. On Friday 16 October at 6pm UK, Bradley Whale and I are running a live webinar on how to tell the source from the compensator. Can’t join live? The replay is available to everyone who registers. Comment PELVIS and I’ll send you the link.
