What Is Hunter’s Bump In The Horse?

Hunter’s bump in the horse is a term used to describe a condition in which the tuber sacrale of the pelvis, located at the highest point of the horse’s rump, are abnormally prominent.

Most people think of this condition as being a breed-specific conformation issue.  It is often found in the “hunter/jumper” breeds like Thoroughbreds and Warmbloods.

Some people even think this is actually a good thing and was an indication that a horse would be a good jumper because it is so prevalent in that discipline!

Most often, however, it is either a function of how the horse is used; i.e. its job and how it uses it’s body, or due to an old injury.  There are varying opinions of the cause, all of which are probably valid.

When it comes to horses they tend to find multiple roads to the same imbalance.

Why Does My Horse Have it?

The three most popular theories as to the cause of hunter’s bump are 1) sacroiliac subluxation, 2)  damage to one or more of the stabilizing ligaments of the pelvis, and 3) injury to one or more of the muscles acting on the pelvis.

As you can see from the illustrations below, there are many muscles that affect the action of both the hip and pelvis.  Injury and/or strain to any one of these can have a significant effect on a horse’s performance and range of motion to the hindquarters.

When injury or strain occurs, the adjacent muscles take up the slack for the injured one.  Depending on the nature of the injury, such as when ligaments are involved, the muscles will sometimes take over as stabilizers to limit the motion of a particular joint in an effort to avoid further damage to the injury site.

Over time, and especially if a condition becomes chronic, the compensating soft tissue becomes overworked itself and prone to injury.  The muscles remain in a constant state of contraction and fatigue easily.

  

As the horse’s body continues to compensate for the injury, certain muscles can become atrophied when they are no longer used as much and others become overdeveloped by comparison.  The new compensated way of moving becomes an ingrained pattern in the horse’s muscle memory and the body is less and less likely to return to a state of balance on its own even after the original injury has healed.

Now add into that mix the creation of scar tissue, which is not very elastic and greatly reduces the available range of motion to the surrounding soft tissue.

With hunter’s bump, constant strain on the sacroiliac joint and ligaments due to awkward landings over jumps, falls, overwork or bad footing can cause damage to the ligaments and soft tissue of the pelvis.  Atrophy begins to occur in the muscles overlying the tuber sacrale, and along with the upward movement of the sacroiliac joint, causes the characteristic “bump” along the top of the horse’s rump.

Is Hunter’s Bump Painful?

Most horses with hunter’s bump will also have associated lumbar back pain.  If the original injury has gone untreated for a long period of time, other conditions can begin to crop up due to the strain of compensation over time.  You might see stifle and/or hock issues begin to crop up as secondary conditions to the original injury.  These secondary conditions will usually persist and/or worsen even with treatment if the original culprit is not recognized and addressed first.

Look for Part 2 of this article next week, which will cover alternative therapies, specific exercises and stretches that you can use to help address hunter’s bump in your horse.

Resources:  Plate 34, Horse Anatomy – A Coloring Atlas By Robert A. Kainer and Thomas O. McCracken, Alpine Publications 1994.

---

Lisa Carter is a Certified Equine Massage Therapist (CEMT), with multiple certifications from several different equine bodywork schools.  She incorporates her knowledge and experience with Parelli Natural Horsemanship, equine bodywork and as a veterinary technician to provide her clients with the resources they need to make informed decisions for their horses.  She encourages and facilitates network building between equine health care professionals, working together to find the best combination of therapies to meet the needs of the “whole horse”.

Are you ready to get better results with your horse?  Put your equine health care team to work so you and your horse can be doing what you were meant to.  Click here to get started!