The sacroiliac joint is not simply another joint of the horse’s back. It is a critical area through which forces generated by the hind limbs are transmitted toward the thoracolumbar vertebral column. Understanding sacroiliac dysfunction therefore requires more than identifying the location of pain. It requires understanding how the horse is using its body.

The Problem Is Not New

In 1969, James Rooney introduced biomechanical analysis into the study of equine lameness. Standardbred racehorses were then particularly prone to sacroiliac dysfunction.

Rooney theorized that “the waggle-tail gait of the harness horse might well predispose to minor subluxation of one or the other sacroiliac joints, tendinous strain, etc.” (1)

He also observed partial luxation of one or both sacroiliac joints in jumpers.

Today, sacroiliac dysfunction is frequently recognized in dressage horses and show jumpers. In one group of 74 horses presenting pain associated with the sacroiliac joint, dressage horses and show jumpers were found to be at greater risk than horses involved in racing, eventing and general-purpose work. (2)

The question is not simply which disciplines are affected.

The more important question is:

Why?

Several explanations deserve consideration.

Modern training techniques may create abnormal stresses upon the sacroiliac joints.

Traditional approaches may also fail to adequately prepare the horse’s physique for the athletic demands of modern performance.

There is another possibility.

When movements are taught without sufficient understanding of equine biomechanics, the horse may learn to reproduce the appearance of the movement without developing the physical coordination necessary to execute it efficiently.

The performance may be recognizable.

The body performing it may nevertheless be inadequately prepared.

This distinction is fundamental.

What the Sacroiliac Joint Actually Does

The role of the sacroiliac joint (SIJ) is to transfer forces generated by the hind limbs toward the thoracolumbar vertebral column.

This transmission involves the surrounding ligamentous and fascial structures, particularly the dorsal sacroiliac ligament (DSIL), the sacrotuberous ligament and their relationships with the thoracolumbar fascia, gluteal fascia and hamstring-sacrotuberous ligament complex. (4)

Below the sacrum is the very strong ventral sacroiliac ligament (VSIL).

Above the sacrum, connecting with the tuber sacrale, is the dorsal sacroiliac ligament. The DSIL includes a cord-like portion extending from the dorsal aspect of each tuber sacrale toward the apices of the sacral spinous processes. This portion is commonly referred to as the short DSIL.

These anatomical relationships are important because the SIJ cannot intelligently be considered in isolation.

It participates in the transmission and management of forces associated with forward motion, balance and athletic performance.

Consequently, dysfunction of the SIJ cannot be adequately understood simply by asking:

Where does it hurt?

We must also ask:

What coordination created the stress?

Maturity Matters

Hastened and superficial education can place horses under athletic demands before their bodies have reached sufficient physical maturity.

Kevin Haussler described deformation of the equine pelvis under load, observing:

“The bones of the pelvis are not a rigid structure and bony pelvic deformation is a normal occurrence in any sacroiliac joint movement.” (3)

This is an important concept.

The pelvis is not an absolutely rigid structure.

Its behavior under load is influenced by the horse’s development, coordination and the forces acting upon it.

Pelvic maturation also continues relatively late. Physeal closure and subsequent development of structures including the iliac crest extend through the horse’s early years.

Therefore, chronological eligibility for advanced competition should never be confused with complete physical preparation for the athletic demands being imposed.

A horse may be old enough to enter the ring.

That does not necessarily mean the horse has been prepared well enough to perform what is being asked.

Sacroiliac Dysfunction Is Often a Training Problem

Traumatic injury can certainly cause sacroiliac dysfunction.

However, many problems develop progressively through repetitive abnormal stresses.

This is why sacroiliac dysfunction must also be considered as a problem of training.

Any training system that applies the same sequence of priorities to every horse without considering individual morphology, balance and coordination risks creating compensatory stresses.

We have rehabilitated horses in which the techniques previously applied were simply ill-adapted to the horse’s particular morphology.

This brings us to a distinction that remains essential:

Learning to show is not the same as learning to ride.

Learning to show can become the process of producing movements that satisfy judging expectations.

Learning to ride is something considerably deeper.

It is the process of developing the horse’s physique and coordination so that the athletic demands of those movements can be executed efficiently.

One concentrates upon the appearance of the performance.

The other prepares the athlete capable of producing it.

When appearance is pursued ahead of physical preparation, the horse pays the price.

Therapy Must Address the Cause

Various manipulations, some adapted from techniques used in human therapy, have been proposed for rehabilitation of sacroiliac dysfunction.

There is, however, an important difference between the human patient and the horse.

A human can understand that temporary discomfort during therapy may contribute to later improvement.

The horse does not reason about therapy in this manner.

When a movement provokes pain, the horse protects itself.

This protective response may create muscular contractions and compensatory patterns that oppose the movement the manipulation is intended to restore.

The objective therefore should not simply be to manipulate a structure.

The objective should be to restore better coordination.

Many movements proposed through therapeutic manipulation can instead be recreated progressively through intelligent work in hand or under saddle.

This requires considerably more than exercises.

It requires knowledge of equine physiology and biomechanics, accurate observation, correct positioning and the ability to recognize how each individual horse organizes its body.

The horse cannot be rehabilitated by forcing the body toward a theoretical position.

The horse must be educated toward more efficient coordination.

The Rider as Therapist

The sacroiliac joint does not function independently from the rest of the horse.

Neither should its rehabilitation.

Forward motion, balance, vertebral coordination, muscular activity and the management of forces generated by the hind limbs are interconnected.

Therefore, the most effective therapy is not simply directed toward the painful structure.

It is directed toward the coordination that allowed excessive stress to reach that structure.

This is why correct education can be both preventive and therapeutic.

A knowledgeable rider does not merely ask the horse to perform movements.

The rider develops the physical coordination that makes those movements possible without unnecessary stress.

The distinction is profound.

Do not train the movement at the expense of the horse.

Develop the horse capable of performing the movement.

When equitation is based upon sound knowledge of biomechanics and adapted to the individual horse, training itself becomes rehabilitation.

And ultimately, an educated equestrian may be the horse’s best therapist.

Jean Luc Cornille

Science of Motion

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