Hoof Angles – Part 4

There doesn’t seem to be an end to what I can find to say about hoof angles! Several of my previous posts have mentioned the consequences of hoof imbalance, and it’s now time to start being more specific about the problems that can, and do, arise from an improper landing due to an out-of-balance hoof. This installment will touch on consequences involving bones and soft tissues.

Photos of ringbone

Ringbone - from Dr. Deb Bennett

The severity of any particular problem is directly related to a number of factors, including: the horse’s conformation, the type and degree of hoof imbalance, the length of time the hoof remains out of balance, the work the horse does while unbalanced, and the type of terrain the horse moves over while unbalanced.

First of all, most horses do not suffer immediate and catastrophic ill effects from hoof imbalance. If that were the case, there would be far more lame horses than sound ones, since, in my experience, more than 9 out of 10 horses have some degree of imbalance. Instead, the effects of imbalance are often not seen until later in life, similar to human health problems associated with things like smoking, poor diet, and exposure to loud sounds. But since my objective in hoof care is the long-term comfort and soundness of your horse, I believe it’s important to understand and address these issues before they become problems at the clinical level.

The immediate problems that do occur from extreme hoof imbalances are lamenesses due to strain on tendons and ligaments. These sorts of issues more often appear to be connected to large and sudden changes in hoof length and/or angle that can occur when the horse is trimmed, rather than to absolute balance. When a large amount of hoof wall is removed, the abrupt change in tendon and ligament tensions can leave a horse uncomfortable for a few days following trimming.

The more serious problems stemming from long-term imbalance are those related to jerk and concussion. Once again, Dr. Deb Bennett in Principles of Equine Orthopedics

The dirty little secret of all connective-tissue cells is that they really “want” to become bony. This is because, like bone, their ultimate structure is strands of the protein collagen, which has a great affinity for calci-apatite, the mineral substance which makes bones hard. When they detect strain, connective-tissue cells respond by coating collagen strands with calci-apatite….To “talk” connective-tissue cells into depositing calci-apatite requires only a little stimulation. This normally comes from gene signals, but stimulation by electric impulses, chemical irritants, or allergens can also start it. More importantly for real horseshoeing situations, so can vibration. Vibration comes to horses in two forms: as jerk, which occurs when ligaments or tendons are sharply pulled on; and as concussion, which occurs when something pounds on them (or when they pound on something).

In other words, if a hoof is out of balance in the front-to-back direction (A/P balance), the weight of the horse will immediately force the foot flat to the ground at the onset of the stance phase, and the ligaments and tendons will undergo a sudden change in acceleration. This rapid change is called ‘third-order acceleration’ or ‘jerk,’ and, as Dr. Bennett states above, it stimulates the conversion of the connective tissue – ligaments and tendons – to bone. Check out A Ringbone Study above for a good look at what happens (this example shows what is usually called high ringbone, and is also a case of articular ringbone since it involves the joint), and think about the consequences of those pronounced heel-first landings so many farriers claim are ‘normal!’

Toe-First Landing

A very pronounced (and destructive) toe-first landing...

On the other hand, if the hoof is out of balance in the side-to-side direction (M/L balance), it undergoes unilateral concussion when it lands, hastening the conversion to bone of the lateral cartilage i.e. sidebone. And remember: as I pointed out in What Makes it “Natural Hoof Care?”, unilateral concussion is practically synonymous with ‘corrective farriery.’ Deliberate imbalance can never fix a conformation “problem” at the ground level, because it originates much higher in the limb – in the shoulder or hip. It can only cause long-term (and sometimes short-term) damage.

Heel-First Landing

...and a more typical, but also destructive, heel-first landing

Why am I mentioning imbalance in a post about hoof angles? Because, as the last post mentioned, the horse does not adjust the flight arc of his hooves based on what’s been done to the bottom of them. So if his heels are too long (high), they’re going to hit the ground first. Likewise with toes that are too long.

For now, I’m going to leave you with the following four points:

  1. Hoof angle is not arbitrary; the only proper hoof angle is the one that properly aligns the bones/joints of the lower limb.
  2. To minimize the forces of landing – jerk and concussion – the hoof must be properly balanced.
  3.  You cannot see a bad landing, unless it’s really bad, without the proper equipment.
  4. Given sufficient movement over suitably-abrasive terrain, the barefoot horse will quickly remove any minor hoof imbalances; however, a shod horse has 0% chance of fixing his own feet.

More later…


  1. Hannah says:

    Can you please go into more detail about the damage caused by heel first landing vs flat.

    All of my horses land flat at the walk but most land slightly heel first at faster speeds.

    • Steve says:

      That’s a great question. Unfortunately, I don’t know of any equine-specific studies that have been conducted to answer it. I think we can make some very logical assumptions based on what we do know, but please understand that I’m doing a bit of speculating in this answer.

      Your comment about landing slightly heel-first at faster speeds is an interesting one. Last week, I was discussing this very subject with Bruce Nock and Ann Corso of Liberated Horsemanship, and Dr. Nock pointed out that he’s been operating under that very assumption – that the horse lands with his feet out in front of him at higher speeds, and sort of “pulls” himself forward. However, he’s recently been observing video of galloping horses, and discovered that their (front) feet land directly underneath their shoulders – in other words, a flat landing even at high speeds! I tend to think of it a bit differently; more like the body is moving forward in space, and the front limb makes ground contact to act as a support for the body passing over it. And the most logical place for that to occur, from an engineering perspective, is directly beneath the horse. So Bruce’s observations make sense to me!

      Coincidentally, I was at the podiatrist last week after having a bout of plantar fascitis. The radiograph showed bone growth at the origin of the tendon, and the doctor explained to me that the constant “tugging” of the tendon causes bone growth at the point where the tendon connects to the bone. This is consistent with Dr. Bennett’s comments in my post – that jerk and concussion stimulate the conversion of connective tissue to bone. He also explained that the tugging is the consequence of imbalance – in this case, improper support for a proper landing – and that the pain I’ve been experiencing is not due to the bone growth, but to the pulling on the tendon.

      It’s the same for the horse. Chronic A/P (front-to-back) imbalances, which produce a heel-first or toe-first landing, will “tug” at the tendon insertions. In the case of the toe-first landing, the insertion point of the deep digital flexor tendon on the bottom center of the coffin bone, as well as the origins and insertions of the proximal and distal navicular ligaments, would logically be the most affected spots. Also affected would be the deep digital flexor tendon and the attendant surface on the navicular bone. With a heel-first landing, the most affected region would seem to be the insertion point of the extensor tendon on the center front of the coffin bone just below the coffin joint.

      Dr. Bennett points out that the other connective tissues in the region are affected as well, although the forces (and effects) diminish as you move farther up the leg. Much of these effects are from the vibration resulting from concussion rather than jerk. But ossification of the various connective and joint tissues – the ligaments and joint cartilages – does occur, resulting in ringbone and sidebone.

      This is why I’m such a strong proponent of balance. It seems obvious to me that our horses’ best chance at long-term comfort and soundness is to stave off the conversion of connective tissue to bone – “arthritis” – as long as possible. And doing so necessarily means as low-impact a landing as possible.

      Hope that helps…


  2. cjs says:

    I’ve been reading several of your blog posts with interest and strongly agree with your comments about balance. However I am on the fence about your comments about there being only one correct hoof form. I am also inclined to disagree about heel first landings always being bad.

    For years I had the unusual role of dealing with the feet of several horses that traveled and competed up and down the east coast, generally barefoot. The stay in each location would typically be several months. Although the jobs were similar (eventing and dressage) the horses were quite different in breeding (from TBs to WBs), conformation, and consequently hoof form. All hoof forms changed surprisingly quickly depending on surface and moisture content of the terrain, although the TB types with their thinner walls and soles did not change as much or as quickly as the WB types with their thicker but more flexible walls and soles.

    I scratched my head about it pretty hard. I ended up concluding that my job was to maintain balance and bony column alignment, in a way that allowed comfort and traction on the surfaces the horses were training and competing on.

    So what some horses did on certain surfaces (parts of New England and Ocala especially) is to spread out the foot a little and develop a little groove in the white line, kind of like the bottom of a St Croix Eventer shoe. Since there was no splitting or chipping, and it seemed as if it would make traction better, I left it. I also left the frogs alone unless I saw any signs of infection. I watched for white line infections and thrush but in all those years we never experienced either.

    We did finally get thrush when another farrier did both horses and aggressively trimmed their (admittedly messy looking) frogs. I’m still figuring that one out but I speculated that the trimmed frogs had less-to-no ground contact and that somehow reduced their resistance to infection? Also our heel first lander, who had terrific caudal frog development, stopped landing heel first and moved more carefully. Hard to say for sure since there are a lot of variables in a hoof, but I speculate that heel first landings may have something to do with frog health and digital cushion development, and not simply with hoof form. I’m hoping for a study!

    I wanted to throw in a few comments there from my experience to see if you or any of your readers had similar or contradictory stories. Thanks for your blog!

    • Steve says:

      You raise some very interesting points in your comments! But, first of all, I think you may have misunderstood what I mean by only one correct hoof form. What I absolutely don’t mean is that all feet should look the same. Feet are as individual as horses, and there’s no question that what’s correct, appearance-wise, for one horse will not be correct for another horse.

      When I talk about one proper hoof form, I’m speaking as an engineer about hoof from a purely functional perspective. And so the one proper hoof form is the one that facilitates the most efficient movement for that particular horse at that particular time while still protecting the foot’s sensitive inner structures. That hoof form will have the same characteristics from horse to horse, but the appearance of the hoof may be radically different. For example, all properly-trimmed hooves will have a rounded outer wall edge, but the radius of that rounding will vary from horse to horse. Or, all properly-trimmed hooves will have bars that are level with the sole, but the size and shape of the bars will be different from horse to horse. So that’s what I mean when I speak of “one correct hoof form.” It’s a functional thing, not a cosmetic thing. But since, as we like to say in engineering, “form follows function,” there will be a similarity to the appearances of properly-trimmed hooves.

      It’s admittedly difficult for me to understand, though, how you can strongly agree about the importance of balance, yet not agree that heel-first landings are necessarily bad. If the foot is three-dimensionally balanced, it must necessarily land flat. That’s not to say that every step a horse takes will have a flat landing, particularly when there’s a rider involved. But, logically, a horse left to his own devices traveling many miles a day over highly abrasive ground will wear his hooves such that they land flat at his most common gait; it simply cannot be any other way. I realize this is a point of great contention in the hoof world, but every other engineer I’ve discussed this with, whether or not they understand anything about horses, comes to the same conclusion. The only possible way that a hoof could make heel contact first and still satisfy the above conditions is if the heels were considerably more compliant than the coffin joint i.e. they touch the ground first, but bend out of the way so rapidly that the foot effectively lands flat. I don’t think this is the case at all, but it’s the only possible explanation that would allow for a heel-first landing and still satisfy the other conditions. I’m working on data to support this position, by the way! But we do have to be careful to look at landings under circumstances similar to the conditions that I described above. And so I qualify flat landings as occurring on a flat, unyielding surface at the walk, with no rider.

      I realize there are many people out there who perform what I term “environment-specific trimming,” but I have to say that I’m not a fan of varying the trim under any circumstance. My reasoning for this, as I explained in one of my posts, is that our horses live and work on a wide variety of surfaces, and the only trim style that provides proper balance on every surface is the trim that mimics the one nature puts on the feral horses of the U.S. Great Basin i.e. a flat landing under the conditions I described above. While it may compromise traction a bit (although there’s no quantitative data on that, to the best of my knowledge), I believe it gives every horse the best chance at long-term comfort and soundness.

      And finally, I suspect the sensitivity you observed is because the frog wasn’t trimmed such that it made ground contact after the hoof wall. We know that’s the proper order of impact in the feral horses, and I’ve now seen quite a few horses with “unexplained” sensitivity who were quickly fixed by simply trimming the frog (and/or the bars and/or the sole) properly. The order of impact is very important for the comfort of the horse.

      Thanks for sharing your story with us; very interesting comments!


  3. MaryClare says:

    I’ve got two horses who slam their heels into the ground, and yet their heels are almost as low and back as they can be. I should recheck heel height but how do you ensure a properly balanced foot. What measurements/guidelines do you use to get as close to balanced as possible? Thanks for your help.

    • Steve says:

      That’s a great question with an answer that’s difficult to explain in writing, and fairly simple to explain while you’re actually under the horse. First of all, keep in mind that balance is exactly that – it’s the ratio of heel length versus toe length, rather than an absolute number. So it’s entirely possible that the toes have been cut too short relative to the heels, and you’ll have to wait for them to grow. That’s actually a fairly common scenario. But you use the phrase “almost as low and back as they can be,” and I’ve found that, depending on what the hoof does just before it hits the ground, even small differences in relative height can make a large difference in whether or not the hoof is landing properly.

      The more difficult part of the answer is, as I mentioned, describing how you can know the hoof is the right length, and I can only give you a very basic general description here. My belief, based on logical reasoning, experience, and observation for many years now, is that the proper length for any hoof can be determined as you trim by observing the tissue at the white line. Nature trims the feral horses who live in suitably abrasive terrain to a consistent tissue depth at the white line, from toe to heel. And so by trimming to this same consistency in tissue, the hoof wall will be the proper length. That, of course, doesn’t describe the rest of the foot trimming – sole, bars, or frog – which is equally important. But that’s how the proper overall hoof length can be determined. As I said – easy to show you, but hard to describe! When a hoof is trimmed in this manner, the coffin bone will be in the proper relationship with the ground and with the rest of the bones in the leg, and will therefore be landing properly.

      I hope that helps. Thanks for your questions!


  4. Matt Stone says:

    Hi Steve,
    Since discovering your website I have been reading your posts with interest, I am just getting into trimming and hoof care and can’t get enough of it I am really enjoying it. Just wanted to touch on the subject of balance in the equine hoof, I live in Australia and we have a master farrier of 50 years by the name of David Farmilo you may have heard of him? He is all about balance and I have been following his method of finding the correct balance when trimming using 3 critical junctions or landmarks 1. the clean active tip of the frog 2. where the widest part of the trimmed clean frog meets the hoof wall at the heels 3. Where the clean sole meets the hoof wall at that junction on the white line. He refers to it as the roadmap and it does make a lot of sense to me he studied this for 10 years through his own work. I’m sure as an engineer you would understand this, correct me if I’m wrong but to balance something is to have equal amounts of that something either side of a certain point or center point of balance. David Farmilo states that the center point of balance in the equine hoof is exactly 19mm behind the clean active tip of the frog from this point you should have an equal distance to the toe once trimmed and flares removed to a line across the trimmed buttresses of the heels. You can also check medial-lateral balance from this point. Obviously there’s a bit more to trimming the hoof as a whole but I just wanted to talk about balancing the hoof as we here it mentioned a lot but when you ask how? you end up getting a convoluted description when to me it should be fairly clear and easy to explain. I think of it as a seesaw, the center point of balance won’t change however adjust the length or weight on one side of the seesaw and what happens? I have been trimming my TB using these landmarks for about 6 weeks and its been quite amazing he is moving out nicely and his hooves are starting to look strong and healthy. Anyway I would be interested in your thoughts.

    • Steve says:

      Hi Matt –

      Yes, balance IS quite easy to explain: M/L balance occurs when the vertical distance to any medial point on the coffin bone is equal to the distance to the same lateral point i.e. the coffin bone is “parallel” to the ground when viewed from the front or back. A/P balance occurs when the distal margin (“bottom rim”) of the coffin bone has approximately a 3-degree “tilt” upward from front to back.

      The “trick,” however, lies in understanding the relationships between the coffin bone inside and the visible landmarks on the hoof. That’s a bit harder to explain in words! But they are generally reliable, although some of them may be distorted in various hooves, depending on what pathologies may be present.

      The point you’re referring to was identified some time ago, and is called “Duckett’s Dot.” However, it’s NOT a reliable spot on the external hoof (any time anyone says anything about a hoof like “exactly 19mmm,” I’m nervous!), as documented in an article in the American Farrier’s Journal by Jaime Jackson. In it, Jaime demonstrated an exception to that “rule” using a feral hoof. And once you have an exception, you no longer have a “rule,” because the question then becomes “do 90% of horses follow this rule, or 60%, or what?” And that’s why learning to trim is about understanding a whole lot of things, and not about a set of numbers.

      I’m glad for your interest in trimming, and I hope you continue with it. And I’m glad your horses are showing positive improvement!

      Thanks for writing.


  5. Matt Stone says:

    Hi Steve
    Thanks for your reply.
    Just wanted to add a couple of things, first of all I myself am not convinced that comparing the feral horse with the domesticated horse of today is an accurate comparison I realise the feral horse is important as far as research goes and I don’t want to sound as though I’m being negative or forcing opinions, I like to keep an open mind but there are several important points that I believe we should all take into consideration.
    The feral horse is not ridden or driven.
    They have differing diets and living environments, and lifestyles generally.
    Now necessity is the mother of invention and
    if we go back in time to when horses were our only means of transportation the horse I’m sure would have been a part of life for everyone and the horse would have been utilised everyday and in a lot of instances all day.
    We couldn’t just walk out the door and jump in our cars.
    Back in the day horses were used in coal mines, wars have been waged on the back of the horse, cattle drovers would spend months on end droving cattle thousands of miles through all sorts of terrain on horseback. In my opinion a barefoot horse would not have stood up to the workload. Hence why the horse was shod. I’m not saying here that shoes are good or bad, I just think that the whole shoes are bad for horses and that barefoot is best needs a little perspective sometimes, we have had studies done of wild horses here in Australia where all the horses looked at had varying degrees of laminitis and hoof deformaties. I believe shoes do have there place ‘providing the hoof is prepared and balanced correctly prior to applying the shoes’ and the horses lifestyle managed properly, I mean its know good having a horse out in the paddock for months on end that is shod so in short if a horse is able to go barefoot I’m all for it and that’s how it should be. I believe it’s poor shoeing practices and poor farriery that are causing the horse problems rather than horseshoes themselves as I have also seen examples of both poor barefoot trimming methods and practices first hand and I believe that everyone that trims a horses hoof has a duty of care to balance the hoof correctly whether shod or barefoot.
    Thanks for your time Steve as I said I’m not biased one way or another just think sometimes we need to reflect and put things in perspective, and compare apples with apples.
    Bit of food for thought…pardon the pun
    Lets all do what’s right for these beautiful animals!
    Cheers mate…

    • Steve says:

      Hi Matt –

      Thanks for your comments. Certainly replying to them could fill an entire volume, but I’ll try to keep it a bit shorter than that!

      First of all, let me say that I agree with your statement about “poor shoeing practices and poor farriery” being the larger part of the problem with the shoeing process. The original intent of the horseshoe appears to have been only to eliminate abrasion from the hoof when the environment and work load meant that material was being removed more rapidly than it was being replaced. Unfortunately, people started attributing near-mystical abilities to horseshoes, like attempting to “correct” conformation/gait “abnormalities” (which is unsuccessful and harmful) or adding support (which they cannot do). So we now have a device which prevents any efforts at self-trimming/self-correction put on top of either unintentional or deliberate imbalance, and we’re now causing damage. I think the evidence that damage occurs under those circumstances is irrefutable, and it sounds like you would agree so far.

      But even under ideal circumstances, if we recognize that the only positive thing a shoe is capable of doing is providing more space between the sole and the ground (I realize that we can also use it to adjust traction – both increase and decrease – and so count that as a more “neutral” characteristic), then we have to weigh that against the negative things a shoe does – prevent self-correction for an optimal landing, change the flight dynamics of the hoof leading to improper and destructive landing forces, increase the load on the horse’s limb by increasing the length and weight of the foot, restrict shock absorption by limiting expansion/contraction, and possibly others that I’m unaware or unconvinced of. And for me, those negatives, combined with the way I see shoes used, are what convinces me that shoeing is more negative than positive. If you read any farrier text, you’ll see that they all recommend having the foot bare at least 6 months a year. Yet how many farriers actually recommend that? So if people did what a friend of mine does – tacks on shoes to go ride in the Rocky Mountains, and then immediately pull them off again – I’d probably have very little issue with shoes, provided they were put on top of a properly-balanced foot. But they don’t.

      Certainly situations do occur where some horses need additional protection, and in those situations, I recommend hoof boots. Boots provide every real advantage shoes only allege to provide. They actually protect the hoof, and don’t encourage the growth of poor-quality hoof material like constantly wearing a shoe does. (In fact, one of the most convincing arguments for not shoeing a horse comes from examining the quality of material – most notably sole – on a horse who wears front, but not rear, shoes. You’ll nearly always see a profound difference; the rears will require a sharp knife to exfoliate, while the fronts can be done with a hoof pick!) But I often hear the excuse that it’s too much trouble to put boots on and take them off. Personally, I feel my horse’s long-term comfort and soundness is worth the extra 2 – 5 minutes.

      Yes, our domestic horses don’t have the same lifestyle as their feral brothers and sisters, and I often hear that used as the rationalization for shoeing. Frankly, I think it’s an excuse, akin to saying that if we can’t feed every starving person, we shouldn’t feed any starving people. No, we can’t go to 100% feral lifestyle and still enjoy the benefits of horse ownership. But we can certainly go some distance towards that goal, and for me, that includes keeping the horse barefoot and using boots for protection as required. I see every advantage, and no disadvantage.

      Thanks Again –

  6. Jutta says:

    Hi Steve,
    first of all thanks for the enlightening articles you put up for everyone to read (for free!).
    I do understand the principle of medio-lateral balance and if we had x-ray vision it would be easy to adjust the trim to the individual foot. For the lack of definitive landmarks I am not sure of where the cb margin is on the medial and lateral sides, especially where diagonal hooves are concerned…
    Any tips for recognizing the actual distance of either side from the ground – except the lateral grooves distance?


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