09/09/2026
“It was never the stirrup leathers”
How you can quick test a true leg length discrepancy from a crooked pelvis and what to do from there
You have punched a new hole in one leather. You have swapped irons. You have had three people watch you from behind on the centre line. And still, every ride, the right one feels shorter.
I want to be clear about something before we go any further: the leathers are almost never the problem, and neither, most of the time, is a genuinely short leg. But “most of the time” is not “never” and the riders who fall into the exception spend years being told to just sit straighter while their body is doing exactly what a body does when the two halves are not the same length. So let’s do this properly. Here is how to work out which one you are.
Before we get anatomical, let’s name the pattern. Riders with a persistent hip-height difference tend to report some cluster of the following:
〰️One stirrup that feels chronically longer, no matter what the leathers say
〰️Collapsing through one side of the waist, usually with the ribcage drifting the opposite way
〰️Circles that drift consistently in one direction
〰️An outside rein you can never quite keep on one side
〰️Saddle that migrates to one side over a session
〰️Uneven wear on the stirrup treads, or one boot scuffing the flap more than the other
〰️Your trainer saying “more weight in the right seat bone” for four years running
None of that tells you why. It tells you the load is unequal. The why is what we’re sorting out.
Two very different things wear the same costume. The single most useful distinction in this whole topic:
1. Structural (anatomical) discrepancy, when the bones are actually different lengths. The femur, the tibia, or both. It is measurable, it is real, and no amount of stretching, mobilising or "realigning" will change it.
2. Functional (apparent) discrepancy, when the bones are the same length, but the leg presents short because of how the pelvis is sitting. Innominate rotation, a hip that lives in adduction, a scoliotic curve, a foot that pronates harder on one side. The limb is not short. The system is arranged asymmetrically.
Both produce identical complaints in the saddle. But they require completely different responses. Which is precisely why guessing is such a bad idea. The part nobody tells riders = a small difference is normal 🙋🏼♀️
Here is where I want to lower your blood pressure before we start measuring things. When Knutson reviewed the radiographic data on anatomical leg length inequality in 2005, the prevalence of some discrepancy was around 90% near-universal. The mean magnitude was about 5.2 mm. Roughly the thickness of a stack of business cards. And the general conclusion across that literature is that anatomical inequality does not become clinically meaningful for most people until it reaches somewhere around 20 mm (2cm). That number tho is genuinely debated. More recent reviews argue that with the right comorbidities (age, sport, hours on your feet, an existing hip or lumbar issue) changes start showing up on imaging as early as 6 mm. Riders arguably sit in that "comorbidity" category: we load asymmetrically for hours, on a moving surface, in a sport that will punish a 5 mm bias by amplifying it into a 10-metre circle.
So my honest position is this: a small difference is normal and probably irrelevant. A large one is not. And the middle ground depends on your history, your symptoms, and your workload. Which is a clinical conversation, not a blog conversation 🎙️🙊
So if your self test measures in the meaningful range, get across to your healthcare professional & book in for a full assessment ~ your horse will thank you!
