Over at the knee conformation

Horse shopping and looked at one recently that had a funky front leg. First thing I noticed was that it looked rather offset. He could stand normally on it but tended to stand without really locking the knee and front leg kind of quivered. It shook worse after exercise. There were several other reasons he wasn’t the horse for me but curious about what this is. I wouldn’t feel safe jumping him long term but owner said it posed no issues. Horse moved beautifully with long sweeping strides. I know I’ve seen it before but always called it over at the knee. Owner described it as tendon problem.

Horses can stand in all sorts of funky ways when they are injured. If they don’t fully weight a leg it can look like bucked knees.

Over at the knee is one of those older confirmation terms that just describes what you see. It makes no reference to underlying causes and pre-dates the x-ray machine and indeed probably modern anatomy dissection.

That leg shaking would terrify me. Perhaps it’s possible some of the stay apparatus of that leg is compromised. If it was hind legs shaking I’d think shivers.

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I seriously question anyone who says a horse that is over at the knee - and demonstrating instability to the point of quivering in the leg post-exercise - “poses no issues” in jumping.

“Over at the knee” is a description of the functional appearance of the issue, but the root cause can be congenital or as the result of some injury that caused restriction in the joint capsule and/or tightening of the tendons at the back of the leg. Many horses demonstrate being “over at the knee” and have no real performance related issues, but this does not sound like one of those horses regardless of how nice his movement was.


I’ve seen what you are describing in a horse that was neurologic. The impingement affected the front legs. It was an obvious cause in his case because horse had fractured his neck and wasn’t like that prior to the fracture and resulting arthritis.


No comment on whether it was right or wrong or good or bad, but many years ago I knew one with exactly what you describe and it stayed exactly the same for many years of moderate jumping work. Very durable horse as I recall - did not show any specific lameness issues, either acute or chronic. It was disconcerting for sure, certainly wasn’t going to win any prizes for conformation. If I were considering one like it I would lean heavily on my trusted vet for a solid PPE and advice, but I wouldn’t dismiss the horse out of hand based on that past experience.


Thanks for the replies! Like I said, this was not the horse for me for other reasons but I was curious if there was a specific name for this. Interesting that it can apparently be caused by many different things.

I think the instability you were seeing suggests it is not just a conformational defect in this particular horse. The neuro horse I mentioned also had lovely gaits until his proprioceptive deficits became obvious years later. And that is also when the shaking / instability would happen with him sometimes.

Sometimes I wonder about the sellers (and/or their vets) in these situations…

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Conformational OATK is pretty rare. Almost always it’s caused by hoof discomfort in the heel region.

Of the rest, it could be from unresolved contracted tendons as a foal, old injury, who knows what else. The quivering isn’t necessarily anything more than a symptom of having to work harder to stand in place with an unlocked knee.

I’ve known a few successful AO Hunters who were OATK in stance. Movement with weight coming down on the leg effectively “locks” the leg


Piggybacking off of JB – exercise enduced OATK (aka not conformational/not born with it) happens in race horses that are shod/trimmed incorrectly.

Whether or not it impacts the future functionality of the knee depends on the horse, how much damage was done to the structures in the knee, and whether future trimming is addressed.

Rode many, many horses that were OATK and never had it bother them. I chalk it up to a “cosmetic blemish” in TBs and STBs as long as they are in work and demonstrably sound in a program.


Neuro issues did cross my mind when I was in front of him. I’ve had 3 with cervical arthritis in my lifetime and all three were big geldings with long necks like him. He seemed very solid in his movement and lateral work but he was worked on a manicured arena too so it might have been a different story out on bad footing.
His angles looked good to me; she told me he did not have contracted tendons as a foal and that this came on later in life. Navicular kind of crossed my mind (not wanting to weight the heel) but he definitely did not move with any choppiness.
In a way, I am glad there were other issues that made me pass on him. There were a bunch of positives about him despite this.

My horse who is currently going through some lameness issues has started to do this. I can’t tell where the pain is coming from but it makes me think her heels are bothering her? She had xrays pulled and no obvious issues. No swelling or heat so I don’t think it is a tendon or ligament issue. She never stood over at the knee before so definitely makes me suspicious

I hope you can figure out what the problem is!

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