Straight Hocks in Sport Horses

[EventerAJ]

Don’t get me started on the crappy conformation photos of sport horses / WB stallions. It’s absolutely intentional, too. The farther out you camp the hind end, the more “uphill” the front end appears. Leaving out the near hind leg lowers the hip and visually raises the wither. It’s an age old trick to make a downhill horse appear level, if a hill isn’t available or the tree-slant is too noticeable when you rotate the image.

I’ve been to FEH Championships three times (winning twice), and I participated in the FEH symposium for years. I’m pretty familiar with what judges want, and frankly the hind end angle is just one part of one score on the overall sheet. Balance, type, and overall impression will beat out minor conformation flaws relating to legs, feet, or a “not quite ideal” shoulder or hip. It has to be really bad for a judge to look into a crystal ball and slam a horse for future unsoundness. Because honestly it’s hard to know-- plenty of horses are very competitive and have long careers with a conformational flaw. Winsome Adante was very straight behind and had an amazing competition record. If a horse is managed well, some flaws won’t inhibit them. So as a FEH judge, is it fair to slam a horse who moves beautifully, has athleticism, talent and type, but MIGHT (in the wrong hands?) not hold up to long term stress of three phases? That’s hard to say, and judges are trained to seek out the best in each horse, not dwell on the negative. A good walk and fancy trot will cover up some imperfections too.

[Marla_100]

Can anyone explain the mechanics of how or why straight hocks leads to suspensoory problems?
I too thought it was due to repetitive loading, fatigue, poor footing etc.

[blue_heron]

If we reduce the hindlimb to a simple lever system, the articulation of the hind limb alleviates or interrupts some of the stress placed on the tendons and ligaments. The hind leg “crumples” for shock absorption and more pushing power. If there’s less bend in the hock, the pastern/fetlock has to support more of the horse’s weight, which of course is where these tendons and ligaments attach.

It’s a gross overgeneralization to look at the bits and pieces of the horse like pictures in a physics textbook. Straightness and strength in these horses is likely to play a much larger role in whether or not they develop suspensory injuries than one aspect of hindlimb conformation, but it’s good nonetheless to understand why correct conformation is important in horse sport and breeding. I’ve never heard a vet say that a diagnoses was “secondary to a conformational fault.” More likely the vet is going to look at the horse’s past training and conclude that repeated stress on the joints in the leg caused the ligaments to degrade over time. Could straight hocks have something to do with it? Maybe (I haven’t read that paper yet), but 12% is just over the threshold of what I would consider a significant finding.

Young horses need to work on a variety of footings, including asphalt and deep footing to strengthen the tendons and ligaments and in some cases improve bone density. Plus, learning to navigate tough footing reduces risk of injury later.

[JB]

@blue_heron

Young horses need to work on a variety of footings, including asphalt and deep footing to strengthen the tendons and ligaments and in some cases improve bone density. Plus, learning to navigate tough footing reduces risk of injury later.

100% agree, just know that you only have 1 to maybe 2 years to significantly impact ligament and tendon strength, but you can still do that with LOTS of turnout with buddies to run around with, ground driving and/or ponying (appropriately of course!), the more varied the terrain the better. After that, it’s really about muscle integrity, and the stronger the muscles, the less work is transferred to ligaments and tendons.

[Marla_100]

thanks for great explanation. @blue_heron. Helps to explain
past injuries in one of my horses.

[Equestrianette]

@blue_heron

I’ve never heard a vet say that a diagnoses was “secondary to a conformational fault.” More likely the vet is going to look at the horse’s past training and conclude that repeated stress on the joints in the leg caused the ligaments to degrade over time. Could straight hocks have something to do with it? Maybe (I haven’t read that paper yet), but 12% is just over the threshold of what I would consider a significant finding.

Young horses need to work on a variety of footings, including asphalt and deep footing to strengthen the tendons and ligaments and in some cases improve bone density. Plus, learning to navigate tough footing reduces risk of injury later.

It is well established that conformation predisposes specifically dressage and event horses to PSD. Very well established. And it is exactly what Dr. Glass from Texas A&M said. You can look her up to see if you think she’s reputable or not. I did everything I could to bring this horse along correctly. His 2 years under saddle consisted mostly of developing the hind end and top line. He rode in my arena, out on pastures, deep footing, hard footing, I very well understood the importance of that and it didn’t matter in the end. Hills, poles, cavalleti, a lot of walking, minimal jumping and usually rarely at home just in lessons with my coach.

[skydy]

@EventerAJ

Don’t get me started on the crappy conformation photos of sport horses / WB stallions. It’s absolutely intentional, too. The farther out you camp the hind end, the more “uphill” the front end appears. Leaving out the near hind leg lowers the hip and visually raises the wither. It’s an age old trick to make a downhill horse appear level, if a hill isn’t available or the tree-slant is too noticeable when you rotate the image.

I had no idea they took lousy conformation pictures on purpose. I’ve always wondered why the Sporthorse stallions had such bad photos. Are they trying to half park them out like Saddlebreds?

As you know, the TB people teach their sale weanlings, broodmares, and stallions to stand properly for a confo photo, so obviously it can be done.

[blue_heron]

I’m not critiquing you; I don’t know what your program looks like. I was replying to the user who asked why straight hocks would create more wear on the lower leg.

[blue_heron]

Okay, I’m sorry and I know the OP probably doesn’t want to hear from me anymore, but what’s been said here is not the same as what’s written in the article.

They found that horses with PSD had larger hock angles than horses with other hind-limb lamenesses and horses that were sound, Dyson said. They also noted that Warmblood horses had a higher risk of PSD than other breeds (“which may suggest an inherent predisposition to injury,” Dyson said), although they did not have larger hock angles.

Why straight hocks are linked to PSD, however, remains uncertain. “Knowledge about the biomechanics of the function of the hind-limb is limited,” Dyson said. “We basically do not know.”
They also cannot make any conclusions about the sequence of events, she added. “To prove cause and effect would require a very long-term longitudinal study, following horses from a very young age,” she said.

They are measuring the hock angles of horses who are already diagnosed. Conformation of the lower limb does affect hock angle. They are not finding horses with straight hocks and saying they have a 12% chance of developing PSD or comparing hock angles of horses pre-lameness and post-diagnosis. This just seemed like a high number and a strong claim to make on a subject that has very little research.

https://beva.onlinelibrary.wiley.com/doi/full/10.1111/eve.13089?saml_referrer

This is the academic paper the horse.com article is referencing. It’s worth a read or at least a look over if you have access. Some of the statistics really emphasize that we need more research on this stuff and that animals are hard to research, but it’s better than a lot of similar papers I’ve read where statistical analysis isn’t even reported beyond standard deviation and the R-value.

[fordtraktor]

So sorry, OP. I will share that my dressage horse, who doesn’t have unusually straight hocks but maybe a little on the straight side, started down this road last spring but we caught it very, very early before any tears existed, but there was some enlarging. I have been able to manage it by being really careful about the intensity of his training and religiously doing ice vibe/cold hose therapy whenever he works on the hard side, supplemented with PEMF. I am also big on a long, slow warmup and cooldown on the vet’s advice.

I’ve also started to be really careful what kind of boots he wears to try and reduce holding heat.

Recently had the vet out for an unrelated thing and his suspensories ultrasound perfectly clean now. So maybe there is hope? Not sure how bad your horse’s injury is, and who knows how long mine will last, but we are back to full work and normal tendons. Fingers crossed for both of us.

[Warmblood1]

@EventerAJ

Don’t get me started on the crappy conformation photos of sport horses / WB stallions.

Yes, it feels a bit criminal I think. I can’t tell you how many dressage stallions (prolific ones, too) that have conformation photos of horses on a very slight hill so as to appear more uphill or more balanced. A lot of these horses have exceptional competition records so you would think that the form of the horse has been proven. Yet they will still manipulate the confo shot to appease what is a popular desire amongst breeders… (although it seems like some should be breeding giraffes if they want something so uphill).

Anyways, @Equestrianette, can you share a pic of your horse? I’m very curious to see how straight we are talking and what the judges found acceptable.

And FWIW, in dressage and certainly with a lot of Iberian horses, I’ve had concerns of horses with overly long tibias/gaskins - the opposite of straight. I feel it’s more common. I feel breeders are trying to produce a lot of hock action but at the detriment of good, functional conformation.

[Equestrianette]

@Warmblood1

I’m very curious to see how straight we are talking and what the judges found acceptable.

I find it to be pretty subjective based on how he’s standing. For a long time I thought he had too much hock angle because he was standing camped under himself.

[fordtraktor]

Thanks for sharing…yes, that is quite straight behind.

I recall in Frank Chapot’s book, he noted several top jumpers were straight behind. Maybe event judges have similar feelings?

I do find that a lot of young horse competitions are based on movement over conformation. The extravagant ones don’t always hold up. But some of the non-extravagant ones don’t hold up either…horses, a thousand ways to break your heart.

[JB]

that’s definitely pretty straight behind. That doesn’t mean they’ll "break’ him, especially since he’s got an excellent front end in terms of his front legs being well in front of his withers, and his neck emerging nicely about the point of his shoulder, both of which serve to make him physically lighter in front, which means his hind end won’t have to work nearly so hard to move lightly and in balance.

Reality is that many judges, and especially vets, just don’t understand conformation in general.

He’s going to be more predisposes to suspensory issues, so excellent hoof care, good training, lots of long slow conditioning with few to no extended periods ouf of work, will help a lot

[Warmblood1]

Thank you for sharing those.

[Libby2563]

OP, this subject is near and dear to me because I also had a young, well-bred horse with suspensory issues. Mine actually wasn’t super straight behind but he had very soft hind pasterns/fetlocks. He did a couple of breed shows as a yearling / 2-year-old and scored pretty well. At 4 he went lame while in light work and at 5 he was euthanized. He ended up having DSLD.

Like you, it bothered me that none of the judges, vets, farriers, trainers, etc who saw him before he went lame seemed to notice what was so glaring to me once it was pointed out by a couple of the vets who saw him after he went lame. (Though to be fair, what are they going to say? “Hey, just so you know, your nice young horse is probably a ticking time bomb”?)

Here is another study about the link between straight hocks and suspensory injuries (https://pubmed.ncbi.nlm.nih.gov/21883416, bolding mine):

Methods: Follow-up information was acquired for 155 horses that had undergone neurectomy and fasciotomy for treatment of PSD between 2003 and 2008. Success was classified as a horse having been in full work for >1 year post operatively. Horses were divided into 3 groups on the basis of the results of clinical assessment and diagnostic analgesia. Horses in Group 1 had primary PSD and no other musculoskeletal problem. Horses in Group 2 had primary PSD in association with straight hock conformation and/or hyperextension of the metatarsophalangeal joint. Horses in Group 3 had PSD and other problems contributing to lameness or poor performance.

Results: In Group 1, 70 of 90 horses (77.8%) had a successful outcome, whereas in Group 3, 23 of 52 horses (44.2%) returned to full function for >1 year. Complications included iatrogenic damage to the plantar aspect of the suspensory ligament, seroma formation, residual curb-like swellings and the development of white hairs. All horses in Group 2 remained lame.

Conclusions and clinical relevance: There is a role for neurectomy of the deep branch of the lateral plantar nerve and plantar fasciotomy for long-term management of hindlimb PSD, but a prerequisite for successful management requires recognition of risk factors for poor outcome including conformation features of straight hock or fetlock hyperextension.

Clearly not all straight-hocked horses break down, but there’s enough evidence that, having gone through it once already, I wouldn’t touch a straight-hocked or soft-pasterned horse with a 10-foot pole. It doesn’t even matter to me what’s the cause and what’s the effect or whether it’s just correlation, because bilateral hind suspensory issues can be fairly subtle until they’re not (i.e., if I can identify something that’s even just correlated with PSD, I will avoid that thing).

As to the 160-degree study, one degree of difference in hock angle is pretty small. For there to be “an 11% increase in the odds of PSD for every degree increase in tarsal angle” (quote from the abstract) does seem significant to me, if you consider that one horse’s hocks could be, say, 5 degrees straighter than another’s.

[Equestrianette]

That’s probably why the vet said he didn’t “need” surgery. I’m sure it’s a difficult thing to tell someone that their horse doesn’t actually qualify for the surgery because of conformation. Especially after hearing all the success stories for horses that are appropriate candidates for the procedure. I still don’t feel confident about determining what is too straight for hocks. I also wouldn’t be able to determine what soft pasterns look like. The vet that saw him earlier in the year that didn’t pick this up in the lameness exam did comment that he had “conformational dropped fetlocks” but somehow didn’t correlate that with suspensory issues. Now that I have seen it I can’t stop seeing it in horses everywhere that demonstrate the same behavior as my horse. I know I’m going to have tunnel vision about this for a long time. I also don’t feel confident in buying another horse because if I thought I did “everything right” with this one and it turned out catastrophically wrong then how can I trust my judgement? Especially when I did seek out the advice of more experienced people, did his PPE at a great vet, my wife is a farrier and provided input, plus all his accolades. This isn’t a 2 year set back. This is a 6 year set back. Because to get to this horse I had to buy and train and sell a different horse just to afford this one. With his condition I absolutely can’t sell him, I just don’t trust people. He wouldn’t even be a good trail horse for someone because he can’t take a joke and is terrified of anything that looks like a trail.
He is insured for a pretty penny, but I don’t know how loss of use works if ultimately I see him being retired with his breeder. I don’t think I’d be confident in a decision to euthanize either. He’s so young. This is awful.

That was a rant I’m sorry

[Equestrianette]

Looking at the pictures I posted would you say he has “conformational dropped fetlocks” or “soft pasterns”? I’m not sure I know how to tell.

[EventerAJ]

Just from the photos you posted, nothing screams “dropped fetlocks!!” to me. However, most functional, nonproblematic “soft pasterns” tend to be on the longer side, and your horse seems to have relatively normal/short pastern length. Typically short pasterns are more upright than long pasterns, and perhaps yours are slightly more sloping than average for that length. I have had a couple young TBs with long, sloping pasterns that (thus far into their young/mid careers) has caused no problem. I have some older broodmares with longer pasterns, too, that so far into their mid/late teens have not dropped into DSLD. Their hock angles are normal.

It would be interesting to see conformation photos of your horse as a yearling/2yo versus now, to see if his hock angle has significantly straightened over time. IME, this is the biggest “tell” of the DSLD syndrome-- the hocks straighten as the pasterns drop.

My retired appendix QH began showing noticeable symptoms (enlarged suspensories, lowered hind pasterns, straighter hocks) around age 21. It began to spread to the front pasterns around age 25. We put him down at age 27; he could still get around well enough, but he was having some sore days and complications with cushings too. Looking back, he had some other ligament injuries during his working career that may have been related and a hint of his future disease-- a distal hind suspensory strain at age 10 (from which he recovered and returned to Prelim eventing, with two different riders); and a check ligament tear at age 17 that ultimately ended his foxhunting career. He was semi-retired at age 20. He lived a long, full, happy life that began as a barrel racer at age 2.