Asymmetrical Pelvis in Horses: Why the High Hip Keeps Coming Back

An uneven pelvis is one of the most common findings in equine practice, and one of the most commonly misread. When the same asymmetry returns after treatment, the pelvis is rarely telling us we failed. More often it's telling us where to look next.

The left hip is higher again.

My hand is resting on the tuber coxae of a gelding who, on his good days, works beautifully, and on his bad days won't hold a canter at all. His owner is watching my face, waiting to hear whether this is the day we finally fix it.

Qualifying is a wonderful moment, and it's the tick in the box that tells us we're safe to treat. Yet once we're out in practice, there's very little ongoing support, teaching or practical framework we can apply to our clinical reasoning in cases like this one, so the traditional model is all we have to fall back on. It teaches the pelvis as a structure that is either level or isn't, and if it isn't, the pelvis must be the problem. So we treat it again, a little more thoroughly, and the gap between the work we put in and the result we see stays exactly where it was.

The pelvis is a junction, not a lever

Most of us learned the pelvis as a list of parts: the sacrum, ilium, ischium, pubis, acetabulum and hip joints. A list of parts quietly teaches us to look for the piece that's out of place, and to treat the pelvis as one rigid lever that is either straight or crooked.

The functional picture is very different. The pelvis sits at the crossroads between the hind limbs, the axial skeleton, the abdominal wall, the fascia and the viscera, and it transmits force in both directions, from the ground up towards the spine and from the trunk back down to the hind limbs.

Load moves through it in a specific sequence. It travels from the lumbar spine through the lumbosacral junction, into the sacrum and the sacroiliac joints, through the pelvis itself and down the femur and hind limb to the ground, and it comes back up the same route with every stride. Every link in that chain relies on the others, so pelvic movement can't be isolated from what is happening above and below it. That's why a hind limb lameness can show up first as a sore back.

Three loads, one pelvis

A useful way to hold all of this in mind is to picture the pelvis sitting at the centre of three loads.

The first is the external load, coming up from the hoof and the hind limb as ground reaction force. The second is the axial load, coming down through the lumbar, sacral and thoracic spine. The third is the internal load, from abdominal pressure, the mass of the gut and any guarding the horse does in response to discomfort. The pelvis has to manage all three with every stride, and when one of them changes, the pelvis changes position to cope.

It runs both ways along the spine, too. Pelvic asymmetry can change how the thorax moves, and a restriction in the ribcage can produce asymmetry in the pelvis.

Not every asymmetry is a fault

Before we decide a pelvis is wrong, we need to know what it was built to be.

Pelvic shape follows biology. A mare's pelvis is generally wider and more capacious, with a rounder and broader inlet, because it has to meet her reproductive requirements. A stallion's is relatively narrower, with a more pear-shaped inlet and a narrower ventral portion. The gelding is the one we know least about, and he needs a question of his own.

A difference in shape isn't dysfunction, and there's no universal template for the perfect pelvis. Asymmetry is a finding, and it isn't a diagnosis.

How it shows up in the working horse

Put those pieces together and the horse from the opening scene makes more sense. The high hip that returns after treatment is often the pelvis doing exactly what it was designed to do, which is adapt to a load that is still there. If that load is coming up from a hind limb that isn't weight bearing evenly, or down from a lumbar spine or ribcage that has stopped moving well, or from inside a trunk that is guarding, then treating the pelvis alone gives us a few good days and then the same horse again.

A pelvis that keeps coming back is often a pelvis doing its job.

That isn't a reason to stop treating the pelvis. It's a reason to stop treating it as the whole story.

The question to add to every gelding's history

When we assess a gelding with an asymmetrical pelvis, two questions belong in the history: how old he was when he was castrated, and whether it was done standing or lying down. A late castration, and the way it was carried out, can leave scar tissue that behaves very differently from healthy tissue.

Scar tissue lacks the elasticity of normal collagen, and it can bind down the abdominal wall, the inguinal region and the surrounding fascia, a little like wearing clothes that are too tight. Adhesions around the remnants of the spermatic cord can pull towards the sub-lumbar region, and restricted fascia in the groin can affect the iliopsoas and the stifle, reducing hind end drive and how well the horse tracks up.

What makes this so easy to miss is how closely the signs mirror a pelvic or sacroiliac problem: lumbar soreness and gluteal tension, reluctance to go forward, difficulty holding the canter or cross-cantering, intermittent hind lameness that doesn't respond to hock or stifle injections, bucking, sensitivity when the groin is groomed or palpated, and a tucked-up stance. In those horses, the high hip may not be the problem at all. It may be the pelvis compensating for an internal load that sits in the scar.

A gelding castrated late

The gelding from the opening of this piece had been castrated at five years old, lying down. He came to me with intermittent performance, struggling on some days to collect or to hold the canter. He'd become resistant in his work, and his posture had changed, with poor development through the extensor muscle chain. His left hip sat higher than his right.

Every one of those signs could have been read as a pelvic problem, and the high left hip made that reading very easy. Once the castration history came into the picture, though, the question changed from "what's wrong with this pelvis?" to "what is this pelvis responding to?".

So I stopped focusing on the high left hip and started treating the tissue around his castration scar, using myofascial release and cross-fibre friction to free up the restricted tissue. Alongside the hands-on work, his owner took on targeted exercises to re-engage the psoas and the hind end muscles he'd stopped using: in-hand pole work, carrot stretches and backing up.

Within six weeks, his owner noticed the difference under saddle. His behaviour became consistent from one ride to the next, and he began to go forward willingly, which was exactly what his rider had been missing. The pelvis had been telling the truth all along. It just wasn't telling us about itself.

Source, compensator or symptom

The practical shift is a change of question. Instead of asking "what did I miss in the pelvis?", we ask "what is this pelvis responding to?".

That leads to three possibilities. The pelvis may be the source, the primary problem in its own right. It may be the compensator, adapting to an external or internal load from somewhere else. Or it may be a symptom, the most visible part of a wider adaptation across the spine or the trunk. Working through the hind limb, the lumbar spine, the ribcage and, in a gelding, his castration history before we return to the pelvis is how we tell those three apart, and it's also how we earn the confidence to explain our reasoning to an owner or a vet.

Knowing where the evidence stops is part of reasoning well, too. Pelvic anatomy and the differences between mares and stallions are well supported, the way load moves between the thorax and the pelvis is a sound working model, and much about the gelding remains an open question. "The evidence doesn't tell us that yet" is a professional answer.

The horse with the high hip isn't asking us to treat the pelvis harder. It's asking us to read it differently, as the place where the problem shows up and not always the place it started. When we make that shift, the asymmetry that used to feel like a failure becomes the most useful piece of information in the assessment.

PS. Bradley Whale and I are teaching exactly this in a live webinar, "When is an asymmetrical pelvis actually a problem?", on Friday 16 October at 6pm UK. We'll work through how to tell the source from the compensator, what mares, stallions and geldings change in our assessment, and what's well supported and what isn't. It's £29, live on Zoom, and the replay is available to everyone who registers if you can't join us live. Book your place here: https://nikavorster.com/pelvicgirdlewebinarsignup

Nika Vorster MSc is an equine chiropractor who treats horses across the UK, Ireland, Asia, Australia and the UAE, and teaches clinical reasoning to equine practitioners.