The Myth of the Heel-First Landing – Part 1

Photo of a Square-Wheeled Bike

– advertisement from Central Semiconductor

Yes, I know it’s been far too long since I’ve posted an article, but life seems to have a way of interfering with my writing! The good news is that I now have  several articles well under way, and so will try hard to keep the gaps shorter.

I had to laugh when I saw the above image as part of an advertisement in one of my technical magazines a couple of months ago, because it seemed as if they knew I was going to be writing this article on heel-first landings and wanted to help illustrate the problem with an easily-understood picture! But that statement will probably make more sense later on…

I want to be absolutely clear right from the start: this notion that horses are “supposed” to land heel-first is, without a doubt, one of the most widely-propagated and dangerous misunderstandings currently in vogue in the horse world. I had intended to start posting my series of articles on navicular disease, but since navicular disease and landings are so closely connected, and because I decided I simply couldn’t bear to listen to one more horse owner or hoof care provider tell me that horses should land heel-first, I decided my priority had to be to weigh in on this very important subject now. In fact, this article could just as correctly be called “Navicular Disease – Part 0.” So although I’ve briefly mentioned in the past that a properly-trimmed horse will land flat at the walk (see, for example, Hoof Angles – Part 4), I haven’t yet discussed the logic behind that assertion at length. By doing so here, I hope to save a lot of horses from a lot of problems on down the road.

photo sequence of a heel-first landing on a bare hoof

A heel-first landing on an improperly-trimmed bare hoof

To be fair, I also need to tell you that I, too, used to believe horses should land heel-first because years earlier I’d read a passing statement in renowned equine pathologist Dr. James Rooney’s book Biomechanics of Lameness in Horses in which he said that horses land flat to slightly heel-first (emphasis added). He did not, however, mention the conditions, such as gait or speed, under which he believed this to be the case, nor did he state whether or not this was a theory based on physiology, or merely an observation of horses he’d encountered. Interestingly, later parts of the same book strongly contradict the heel-first part of his statement, which he then supports with both theory and observation, and his most recent writings on the subject clearly state that the horse should land flat at the walk. In his webpage discussion of feral hoof form entitled “The Shape of the Equine Hoof,” for example, he says:

At the slow walk, the hoof usually contacts the surface over the whole bearing edge of the hoof wall; that is, the foot impacts flat-footed.

Unfortunately, this fallacy about heel-first landings still persists, largely (I believe) because one particular barefoot clinician has stated it many times in his clinics, and because humans tend to land heel-first. But long before I’d read Dr. Rooney’s most recent work, or even his earlier work more carefully, I’d already come to the conclusion that common sense tells us a properly-trimmed horse – whether by nature or by human – must land flat at the walk. In talking to many people over a number of years about this subject, I’ve found that non-horse people, especially technical types, tend to immediately understand why, while many horse people seem to struggle with it. But I’ll do my best to make it clear!

photos of a proper landing on a properly-trimmed bare hoof

A proper landing on a properly-trimmed bare hoof

In this installment, we’ll take a look at two things we need to understand before really discussing the landing problem at length: first, the differences between biped and quadruped limb construction and movement, and second, the issues surrounding how humans perceive landings.

As you’ll see in this image from Dr. Deb Bennett’s Principles of Equine Orthopedics Part 1 comparing the equine and human forelimb, they’re very different in both structure and function –

Comparison of the horse and human forelimbs

So in the forelimb, what we generally refer to as the horse’s “knee” is in fact his wrist, or carpus. The horse actually walks on a hoof attached to what would be the last joint of our middle finger. In the rear limb, the horse’s ankle is the hock joint, and not the fetlock as may seem intuitive. The image below shows their comparative anatomy; the hock image is from Principles of Equine Orthopedics Part 1, and the ankle image is from www.kidport.com –

Horse & Human Ankle Joints

As we consider differences in the way we move, it’s important to note the consequences of these anatomical distinctions. The human ankle consists of an inverted cup of bone perched on top of a ball, stabilized by ligaments. It’s quite compliant by design, and although it flexes fairly readily in both the front-to-back (A-P) and side-to-side (M-L) directions, it’s less stiff and has a far greater range of motion in the A-P direction. In contrast, the forelimb diagram above shows the lowest joint in the equine limb to consist of much broader surfaces designed to articulate only in the A-P direction. With good reason, I might add; if you’ve ever rolled your foot to the inside in a misstep, you can imagine the “train wreck” that would occur if a horse were able to do that at 40 MPH! That complete lack of lateral flexibility, incidentally, is also the reason so-called “corrective” trimming & shoeing is such a long-term disaster, as I pointed out in What Makes it “Natural Hoof Care?”.

The following image from R. C. Schafer’s book entitled Clinical Biomechanics: Musculoskeletal Actions and Reactions (2nd ed.) is very helpful in understanding biped locomotion. Pay particular attention to where the torso is with respect to the leading and supporting limbs –

Diagram of the human gait cycle

And here’s what the author has to say about the mechanics of walking:

Biomechanically, walking can be considered as a series of continuous losses and recoveries of balance in which the rhythmic play of muscles narrowly averts toppling. Steindler refers to the basic sequence of movements in walking as a “series of catastrophes narrowly averted.”

In other words, walking in a particular direction involves shifting your center of mass in the direction you wish to go, and then “catching yourself” with the leading leg as your mass comes over that leg. In essence, you fall forward to move forward. And if your foot is in a neutral position – basically perpendicular to the axis of your leg – it strikes the ground more and more heel-first as your stride length increases.

The quadruped, on the other hand, doesn’t walk like that because their center of mass is never ahead of the leading limb while it’s loaded. The cat in the following (bad!) photos walked through my video setup while I was recording a horse. As you can clearly see, he’s stable on 3 legs and his center of mass is behind the leading leg. Like your horse, he doesn’t have to “fall” onto the leading leg like you and I must do to move forward. You’ll also note he’s definitely not landing heel-first, and I didn’t even have to trim him! –

photo sequence of a cat landing properly

Someone forgot to tell this cat he’s supposed to be landing heel-first…

The other part of this background information has to do with how humans perceive things. Back in 2008 when I began to seriously question this notion of a heel-first landing being “correct,” I became convinced that humans probably aren’t able to see differences in timing between heel contact and toe contact. So I wrote to a number of researchers in the field of visual perception, and posed the following question (since I couldn’t assume they knew anything about horses!):

An observer watches (but does not hear) someone slap both hands down on a tabletop in a brightly-lit kitchen. At what interval between slaps will the hands striking the tabletop appear to be a simultaneity?

The responses I received were all nearly identical, but Dr. Ken Norwich, Professor Emeritus at the University of Toronto’s Institute of Biomedical Engineering provided the following answer with some qualifiers:

How bright is the light used to make the observation? The interval you seek will depend on the illumination. What is the background to the images of the hands? Let us assume that it is a black background, but contrast will also affect the measured interval. Probably the interval is very close to the reciprocal of the flicker fusion frequency i.e. the frequency of flicker where an observer sees a steady image rather than a flickering light. This frequency is about 55 seconds (-1), so the interval you are looking for is at least as great as 0.02 seconds, or 1/50th of a second, and that is for a very bright image.

So in brightly-lit conditions against a high-contrast background, the limit of a human’s perception is in the neighborhood of 20 milliseconds. Any timing difference between heel and toe contact shorter than that will be seen as a flat landing. And just how many barns have you been in where you find “brightly-lit conditions against a high-contrast background?” Darned few, if any, in my experience!

To help put things into more meaningful terms, observe the first set of hoof images in this post. This heel-first landing, from heel contact to toe contact, was quite obvious to me at normal speed, and measures approximately 80 milliseconds.

And now take a look at the following two landings –

Horse Bad Landing

Draft Bad Landing

In both of these cases, the heel-first landing wasn’t particularly apparent at normal speed, and only became obvious when I slowed down the video. Although the background isn’t very high-contrast, the lighting was reasonably bright. They both also measure approximately 20 milliseconds from heel down to toe down. In fact, of the 6 heel-first landings I happen to have slow-motion video of as I write this, the average heel-to-toe contact time was only 32 milliseconds – alarmingly close to the limits of human perception under ideal laboratory conditions.

Therein lies the rub: if you can see an obvious heel-first landing, the landing must be very heel-first in order for you to perceive it as such! And soon I’ll explain why that’s a serious problem for your horse.

So those are the first two hurdles to overcome in this discussion of landings in horses: regardless of what you may observe about human movement, you cannot apply it to equine movement because horses and humans are fundamentally different; and, the timing of a heel-first landing strains the limits of human perception, so you can’t be absolutely certain of anything without using additional tools such as slow-motion video.

More soon…

Comments

  1. Cathy Dee says:

    Thank you so much for this informative and well researched blog 🙂 I have often wondered abojut the notion of a heel first landing in a horses limb, it just seemed wrong but I couldn’t put my finger on it. You have explained it beautifully keep it up! I look forward to further posts.

  2. Ann Corso says:

    Steve, I always look forward to your posts. Thank you for taking the time to share your insights.

  3. Nancy Ash says:

    It seems to me that if a heel-first landing sequence is perceptible with slow motion cameras, it doesn’t matter that human sight cannot perceive it. It’s still a heel-first landing. I’m awaiting your next installment to see what your perception of a normal good-for-the-hoof landing is at the walk and at speed.

    • Steve says:

      You’re absolutely correct: a bad landing is still a bad landing, whether we can see it or not. That’s the reason I mentioned it; because although we can’t see it, the horse is still doing damage. However, I do believe the extent of the damage is probably proportional to the extent of the heel-first landing, so the ones we CAN see at normal speed would seem to be the greatest problem!

      Steve

  4. Teri says:

    Thank you for publishing these articles. I moved away from my excellent trimmer and have now had to trim my horses myself for two years. Trimmers in this area left my horses lame, blowing abscesses repeatedly, having all kinds of cracks and landing toe first. I knew this was ALL WRONG! I got the same explanation from each of them. “You live in a different climate now” While this is true, I know it is possible to have sound horses in ANY climate. The only way to save my horses soundness is to do it myself with the knowledge gained from my 10 year trimmer and keep up with info from other knowledgeable people such as yourself. A funny thing happened once I started trimming. No abscesses, hoof cracks, toe landings and the nicest frogs I’ve seen in a long time. Thank you again for the helpful info.

    • Steve says:

      You’re very welcome. Yes, horses can be healthy and sound in any climate, and I’m glad you’re able to take care of your own horses!

      Steve

  5. danrigal says:

    Do you know that dancers land toe first not to hit the vertebra neither than the joints !

  6. Heidi Meyer says:

    Can’t make a judgement on the “correct” barefoot horse or the other hooves as no photo of them to show correct form was given. IF the hoof is unbalanced, then the landing will be such….toe or heel. Of the healthy horses that are on my books, I have photos of them landing heel first, walk trot canter……and it’s when they land toe first that we know we have an issue (heel bruise or over ready for a trim). There are issues in the hoof that support heel first as being healthier. I guess my issue with this article is that just stating they are correctly trimmed/balanced doesn’t mean they are. A better example may have been to have a hoof pre trim and post trim and see what biomechanics you have going on. Toe first aggrivates the DDFT upon load……heel first there is no aggrivation of DDFT…when the hoof is properly balanced.

    • Steve says:

      Actually, Dr. Rooney makes a pretty compelling argument for DDFT damage with a repeated heel-first landing, as you’ll learn later in this series. Thanks for your comments!

      Steve

  7. Tim Rogers DVM says:

    The reason that heel first landing is well accepted in the vet world is not because some barefoot “guru” promotes it but because there is substantial evidence to support it in the clinical and scientific arena. I’d believe Dr. Robert Bowker DVM PhD with 15 years of experience in researching hoof anatomy, physiology and biomechanics, and he supports the heel first landing as physiologically correct and in fact essential for proper foot development. You mentioned Rooney’s book, and he mentions multiple pathologies that he believes result from a toe first landing causing a resultant snapping action on the DDFT. Radiographs of the distal phalangeal joint show a gross difference between heel and toe first landings, with toe first producing a backward luxation of P2 on P3 and impingement of the navicular bone and impar ligament. This does not happen in a heel first landing. It is true that the human eye cannot assess the moment between heel landing and foot flat; however the eye does have time to assess the plane of the sole for the period before landing and can judge heel first from that period before landing rather than the period between support phases. As supported by Dr. Bowker’s research, a heel first landing appears essential in early years of a horse’s life in order for that horse to develop robust rear foot internal structures such as the digital cushion and lateral cartilages. What is true is that a horse that has landed toe first for the first 5 years of her life will likely never developed a robust back of the foot that can tolerate a heel first landing. These horses lack adequate internal structures, clearly seen in dissection, and are in fact that population of horses that are put down in their first 10 years of life due lamenesses such as navicular. I see some great scientific evidence to support the heel first landing coming from people who have dedicated their life to understanding the hoof. I’ve yet to see any real scientific evidence to support toe first as being anything but pathological. Finally, if you compare a cat to a horse, even that cat lands on the palmar surface of p3, otherwise it would be landing on the top of its foot or at least on tip toes. Though comparing a cat to a horse is a poor analogy, even the cat you show is landing “heel first” as we define that in a horse, landing on palmar aspect of p3 first.

    • Steve says:

      Thanks for your extensive comments. I’m not in any way advocating a toe-first landing; it’s absolutely correct that it causes damage. But if you’ll bear with me, I think you’ll understand why a heel-first landing also causes long-term damage, and why the feral horse cannot possibly be landing in any manner other than flat-footed (which Dr. Rooney agreed with).

      Steve

  8. Anni Paulekas says:

    I wondered why a cat was brought into the discussion about how a horse may land on his foot.
    I am a beginning trimmer. My laypersons sense tells me a horse needs to land on a structure trimmed to allow a strong landing. Neither excess heel nor toe nor Bar should act to twist or torque the upper structures.
    It seems that the foot should be free and flexible. I feel successful when I see my compromised OTTB do an extended trot down the drain rock driveway. He could easily choose the pasture! I feel successful when I see hoof packs littered around the acreage. That makes me think the foot is flexible, dense and strong. I makes me think the foot must be landing using at least the quarters as a basis for a secure landing. I too, would have liked to see videos corroborating your statements. I see so many long toes out there. Lon heels, long bars. I welcome your blog as I am a beginner and every discussion leads to knowledge.
    Thank you
    Anni

    • Steve says:

      I mentioned the cat simply because no one has attempted to force his feet into a particular form; yet, he lands flat. And his leg structure is very similar to the horse.

      The “structure trimmed to allow a strong landing” is the entire hoof landing neither toe- nor heel-first.

      Steve

  9. Cordy says:

    Considering recent studies have even proven that humans, if barefoot, do not land heel first. Shoes etc have caused this in humans as well and a heel first landing causes a great deal of shock to all the joints. So this makes perfect sense to me.

  10. Tomas Teskey says:

    Hi Steven, Looking forward to reading more! I love the video and study-in-motion. You may be geared up for this all ready, but wanted to mention that the terrain/surface a horse is moving over is fully half of the equation in this sort of study, and hoping you have some insights to add with this as part of the overall consideration. Best, Tomas

    • Steve says:

      Hi Tomas! Thanks for your kind words. Yes, the surfaces figure greatly into this work, and I hope to be able to present data that’s been gathered on various types of terrain. The terrain seriously mitigates the forces of impact – something that seems to be ignored in many discussions of movement.

      Steve

  11. I appreciate how much thought you have put into this, but your reasoning is specious. The proof that horses land heel first is in 30 years of force plate records that say so, not video. The landing pattern of ALL terrestrial animals requires deceleration, then full loading with a vertical limb, then acceleration. There is no argument possible– this is the mechanics of all locomotion. The poster above who agreed with your ideas, comparing it with human gait is missing the point that humans running naturally still land back to front, but only within the “ball” of the foot.

    • Steve says:

      Thanks for your comments. I would certainly agree with the second part of your statements, but they’re not at odds with my assertion that feral horses land with no 3rd-order coffin joint acceleration. And, as I described in Part 3, the fact that 30 years of force plate investigations show horses landing heel-first does not mean that they’re supposed to land that way; it merely means that the ones we’ve measured land that way. The fact that hooves wear also cannot be disputed, nor can the logical conclusion that sufficient movement over abrasive ground will eventually yield a flat landing. Dr. Rooney came to this same conclusion because it’s a logical conclusion!

      Steve

  12. Caroline Trayes says:

    You talk about forcing the horse to land heel first. How do you explain the fact that every single horse I see in real work, where the rate of wear is matched by the work and human interference to trim is not required ALL land slightly heel first. This is clearly, to me, the natural biomechanics of the horse. You have to interfere to make the horse land flat, not to make it land heel first.

    • Steve says:

      Hi Caroline –

      Thanks for your question; I hope I answered it in Part 3 of this series. You don’t have to “interfere” to make the horse land flat, you simply have to trim him as nature would trim him under the feral conditions of movement and terrain, which we never see in any domestic horse environment.

      Steve

  13. Cynthia says:

    Hi Steve! Remember when Brian Hampton came to the Gateway Clinic and made his presentation? They had done an extensive study, moving horses over pressure plates, to determine the truth of the heel first landing. As you state here, they found that the heel landed about 1/50th of a second before the rest of the foot. I remember him saying that some people can hear that on a hard surface, but no one can actually see it.

    • Steve says:

      Thanks, Cynthia, for your comment. I now firmly believe Brian saw the result he did as a very direct consequence of the terrain over which the horses in his sample traveled. In reality, they would not have landed heel-first at all, as measured by acceleration of the coffin joint, on their native terrain – the heels would’ve simply penetrated the ground with no coffin-joint rotation. I’m working on a much more thorough explanation – with data – of this phenomenon.

  14. Bruce Nock says:

    Thank you Steve for posting this excellent article. It is interesting that the very few that disagreed with points in the article refer back to data that has been collected on horses with hooves shaped very differently than those of the horses of the Great basin here in the US and of the dessert Brumbies of Australia … horses that rely on strong, healthy feet to travel long distances for food and water. In fact, in some, perhaps many, cases the data referred to may have been collected using shod horses. When you start with a faulty premise, even the most logical argument is likely to result in incorrect conclusions. Data, regardless of how meticulously collected, can lead to incorrect conclusions if the conditions under which it was collected were aberrant. I would expect someone with academic credentials in the field of science to understand this and not make the mistake. I might add, that the exaggerated heel-first landing advocated by Dr. Bowker can only result when the horse is moving with his balance far to the forehand, a condition that puts undo stress on the joints of the front legs and eventually results in pathological conditions that cut the healthy life of the horse short. The question of whether a correct landing is imperceptibly heel first or not may have academic merit. But the problem for horses is that people are trimming horses so that they land perceptibly heel first … again a condition that will undermine the horse’s soundness in time.

    • Steve says:

      Thanks, Bruce, for your insightful comments. Yes, as I continue to examine this issue, I become even more convinced that much of what we believe to be true about how a horse is “supposed” to land is incorrect because of a lack of understanding of why we see what we see. As you point out, it’s not that there’s anything necessarily wrong with the methodology; rather, the problem is with the data being seen through the “lens” of our own preconceptions. And that can, and does, lead to incorrect conclusions about causality.

  15. LL Atlanta says:

    The problem with your theory is that physics wins. A rod with joints will be strongest when all the joints are straight. for a horse with a leg out in front of his body that would be with toe up and landing heel first. the most force is applied at first impact. Physics says you want the rod the strongest when the most weight is applied. Anatomy and physics wins, see the drawings and physics equations related to the forces in “the Lameness of the Horse” by Rooney.

    • Steve says:

      Thanks for your comment. You are partially correct. First of all, the moment of greatest force is not at initial ground contact, but, instead, is when the foot comes under load. If you study slow-motion videos of the horse at various speeds, you’ll note that maximum loading, as seen when the fetlock has dropped to its lowest position, occurs when the leg is under the shoulder, and not in front of the body. In that position, as Dr. Rooney pointed out, it is best equipped from a mechanical point of view to absorb the load in the suspensory apparatus. The somewhat misleading thing about some of Dr. Rooney’s illustrations is that they don’t make it evident enough that the body of the horse is also moving, and in the opposite direction of the motion of the leg. In essence, you can think of the virtual axis or rotation of the system as a whole as being somewhere in the middle of the leg, and not up at the shoulder or hip of the horse.

      Steve

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