Posted in  Understand Hoof Health  on  18 March, 2014 by  Debs Crosoer

What’s happening to the internal structures in a horse with underrun heels and how do the forces on the hoof capsule help or hinder the recovery?

In part 1 we looked at the hoof capsule,
In part 2 we looked at the position of the internal structures,
Now let’s look at how they go together…

When the heels have underrun the laminar that grow the hoof wall are pointing forwards more than they should be. This causes the heel purchase (bit the horse should be landing on) to be further forwards. In part 2 I showed how this has a negative effect on the pedal bone, but what does it do to the other internal structures?

Underrun heels 01

I’ve rotated and marked up the photo of the foot with the horn at the heels missing to show what affect ground forces may have. The yellow line shows where the ground level usually is for a horse with underrun heels. Obviously it’s not exact, it will depend how long the heels get.

The blue arrow is showing where the direction of pressure is going for the horse who is landing correctly and while standing. You can see how the pressure will actually be pushing the heels further underrun (but just a little bit more).

While this looks bad, if you can get a correct landing, and provide enough healthy stimulation to the frog, and thus the digital cushion and lateral cartilage, then you’ll find the heels will recover in spite of the slightly less than ideal direction of pressure.

The important part is getting the healthy stimulation on the soft structures. While they are soft – they’re also remarkably strong and hold the shape of the hoof together far more than we give them credit for!

If a horse is landing more heavily on the heel, and it’s highly likely they are, then there’s going to be a problem. Often the easiest way to spot an excessive heel first landing is when a horse is walking towards you. They’re flicking their toes in the air just before they land. (sometimes this is mistaken for good extension or ‘floaty paces’)

Look at the hooves, if you can see any sole or a dark shadow under the foot as they land, then they could well be landing excessively on the heel.

The orange arrow shows the direction of force on the hoof when there is an excessive heel first landing. It’s easy to see how this will crush the heels underneath themselves, thus causing and increasing underrun heels.

You can feel this for yourself, if you like. Right now! Stand up. Yep, I mean it! Up on your feet give this a go – I promise it’s not going to be like an exercise video, or anything 🙂 (though now I think about it, the idea of a bunch of people all over the world standing up and jumping about while reading this post makes me smile!!)

You need to be wearing shoes for this. Walk a few steps normally with a slight heel first landing. You’ll feel your foot slipping forwards very slightly in your shoe, or your shoe is being pushed backwards. That’s normal heel first landing and stimulates the heel structure just how we want it.

Now walk a few steps, but just before your foot reaches the ground, flex you ankle as much as possible so you land more to the back of your heel. You’ll feel your shoe pressing up against your heel and your shoe is being pushed forwards.

If your shoe were a hoof capsule, it would be underrunning.

There’s a number of ways of trimming underrun heels to correct them (allegedly), most of which involve taking the heels lower than they should be. For me, this raises a number of questions…

1. If the problem is caused by how the horse is walking, how can it be fixed with trimming?

2. The lower you take the heels, the further back the heel purchase is, so you’re putting the pressure on the back of the laminar, increasing the crushing effect, so how are you helping?

3. What caused the problem in the first place? What have you done to address it?

4. Your solution should address the cause of your problem… If your solution is to trim the heels lower than normal, then the problem you’re addressing is that the heels weren’t trimmed lower than normal… Does ‘lack of the heels being too low’ cause underrun heels?

So some of those questions sound fairly ridiculous, I know that… But they’re kinda valid… Just because something is being done all the time, doesn’t mean it’s well thought through!

I completely believe underrun heels can be fixed, I just don’t think it’s achieved by trimming tricks. A good trim is essential, of course, but that doesn’t mean the trim is the driving force behind the hoof recovering. Similarly I don’t think shoes improve things all that much.

Stimulating the frog, digital cushion and lateral cartilages in the right way, by using a balanced trim, exercise, nutrition, and correct movement is what I think is going to get you the results you’re after. The really good news, is 3 of those 4 things are completely in your control…

Did you miss the other parts to this Underrun Heels Explained series?
Part 1
Part 2

Does your horse have underrun heels?
Do you know a horse with this problem?
Has this post helped you understand why it’s happening?

Let me know in the comments below


Laminitis Warning Signs

Laminitis can affect any horse...

Does your horse suffer with Foot Soreness, Persistent Hoof Infection, Wall Cracks, Flare, or Underrun heels?

These problems can be signs of low grade laminitis. Inflammation (laminitis) in the hoof can cause deformity and soundness issues. Trying to fix the hoof without identifying and addressing the inflammation feels like pushing mud uphill.

Do you know what to look for? We discuss 35 different early warning signs that inflammation is affecting the hoof, explaining anatomy and function, what laminitis is, how it affects the horse and hooves and practical things you can do to address the problem without losing your mind!

About the author

Debs is a practicing Equine Podiatrist with over 15 years experience, author, and educator.

She’s here to show you how to simplify your horse’s management painlessly so you feel in control and have a straightforward system that works for you.

When she’s not working you can find her playing with her own horses, watching geeky sci-fi or baking epic cakes.

  • Hi I have a Welsh A not presenting typical lami, she has had a single hind limb detectable pulse / swelling around pastern/ fetlock and a very strange heel: toe gait in walk on the hard. I initially thought she had a strain and have box rested her but … I’m now thinking it could be lami. I’ve looked at the course unfortunately my last horse had ppid so I’m not a newbie to lami & my A is fed < 10% S&S feed and soaked hay but … she is prone and she is walking very exaggerated heel toe .. she goes out for 2hrs but at 11.1hh she is in a mixed herd of horses up to 17hh. She did get ‘trashed’ last time she was out 2 weeks ago when they were galloping about hence I thought she had a strain … in 50 years I’ve not seen anything quite like it she also pivots on her hoof in a circle and doesn’t pick the hoof up. Unfortunately I am disabled and on benefit so I have to extra careful with money so I wanted to ask if you could help offer thoughts before I purchased the course Apologies if this is rude I have ADHD and I don’t mean to be …. Many thanks xx Poppy’s Mum xxxx

  • Thank you for describing the toe-flicking of the under-run heel! It is distinctive and distressing to watch, at least for me. Since my rescue stallion HATES having his hooves worked on I can support your position that exercise, nutrition and correct movement will result in improved hoof balance. Making sure he has room to move on dry rocky ground and good nutrition made a huge difference in a matter of weeks. The hardest part for me was watching giant crescents pop out of his quarters- but that was what expanded the circumference of his hoof wall and allowed the heels to start migrating back into their correct position. And as his hooves improve, I have been able to persuade him that allowing me to pick-up his feet and fine-tune his hoof-shape will make it easier for him to move.

  • Hi, I understand this post is from a while ago, but I had a couple questions. I am trained in natural hoof care and have a 2 year old I have been trimming since he was a little over 10 months old. I was the only one to ever trim his feet and he has always had really good feet. Just recently his feet have begun to drastically mature from baby horse feet to adult horse feet. Of course this has been happening the entire time, I am simply beginning to see it more prominently now. Between the time span of one trim cycle, which is about 6 weeks, I noticed that his heels were looking quite underrun. In fact, reading your articles, they are most definitely underrun. The front hooves being only slight underrun, and the back hooves being much worse. I had never seen even signs of this in his feet. He has always been barefoot, and always will be. He has a diet of grass hay, triple crown growth feed, and a supplement of platinum performance GI. He gets plenty of movement, going out for a large portion of the day on a roughly six acre portion of land (sage brush and weeds). I see no reason why he would begin having underrun heels. Or why it would happen so fast, which from my understanding is not normal. What are your thoughts on this? I understand that trimming is not the only factor in this, but what would be the best way to address this in regards to trimming? He has healthy frogs, and see no reason why he would be landing wrong. Any help is greatly appreciated!
    Thank you,
    Bailee Vargas

    • Hi Bailee, sorry for the slow reply, I’ve only just seen this.

      Horses are born with underrun heels, as they haven’t had any weight on them yet to stimulate the lateral cartilages.

      There will be 2 reasons that a horse has underrun heels. 1 that the lateral cartilage is weak because it’s not getting enough stimulation. 2. that the lateral cartilage has collapsed because it’s getting overloaded (ie too much stimulation). If the frogs are large, then I’d suspect overstimulation, as lack of stimulation would likely result in a weak frog too.

      Look at the posture and movement. Is the horse carrying the weight on the hinds too much or rocking back? I’d have a good bodyworker look at them. If you can’t find the cause in the external environment, then you need to look at the internal environment.

      That said, the most common cause of underrun heels in a youngster is not having enough access to hard ground. If you’re sure the heels were strong, but have now underrun, then look at the body. If there’s any chance they’ve been underrun for a while, and you’re simply more critical (for whatever reason) then it may be that they just haven’t developed properly.

      (Is there any chance he was ridden in that time?)

  • Hi
    I have a mini shetland. A farrier trimmed him when i first moved area, every time he trimmed the pony ended up with abscess on both fronts on the outer wall. The pony now suffers with that area of the hoof wall ALWAYS curling under between trims. I do not use a farrier now i use a barefoot trimmer. Pony no longer suffers abscess but still the hoof curls. I have owned him from 8mnths and never had foot issues with him until my move 5yrs ago and leaving the farrier i had. Pony is now 17yrs.

    • I’m glad you’re not having abscessing problems any more. The curling hoof can be due to problems higher up. I’ve worked with a shettie who had a similar issue. The only thing that helped was bodywork.

  • Hi and thanks, I see a lot of problem with horses over the whole body because they are ridden as if it’s the front of the horse you ride when in fact the back of the horse should be ridden. They fall forward and put their weight on front legs and lose strength they need in the back legs and back area in general and that misplaces the weight and that causes problems in the whole body including the hoof. Thanks for the 3 parts explaining this issue. I didn’t knew about it all, got sucked in by the picture!

    • I think a lot of horses have pain in the back end (often the SI joint due to being over worked too young). This is what’s causing them to lean on the front end, get weak behind, and overload the front feet causing more issues with the hooves.

  • Thank u so much, I’ve been battling navicular with my boy for 9 months now & this explanation of underrun heels has really helped me visualise what’s happening. If u could also explain abit more to me what’s happened that his underrun heel has been shortened over a few months but now the inside has wrapped under & his seat of corn is soft & sore
    He is shoddy at the moment

    • It sounds like his heels are still underrunning. With long term problems like this it’s very hard to say anything useful without seeing a lot more of the problem. Sorry that’s not more help, but there’s a lot of different things that may be a factor, and it’s definitely not going to help if I’m banging on about the wrong thing 🙂

  • My Dartmoor suffers with underrun heels. At the moment she is recovering from laminitis and so her toes are very long and flat at the front inch where the stretch is growing out.
    I can’t get a podiatrist to come to me… They live too far away. I do have a liberated horsemanship trimmer come to me every so often, when she is in my area. So it’s largely up to me. I walk her as much as I can, weather permitting when I’m not working. She has a forage based diet. She is walking very obviously heel first and has been for quite a while. I worry about it as I know it’s not good. Any helpful comments appreciated.

  • Hello! I have a six year old horse (smart Irish competition horse) who I bought a year ago with under-run heels. Feet were x-rayed from the side recently and the pedal bones on the hinds are angled upwards (have got the x-ray if you want to see it!). He’s currently on 8 weeks box rest from a stifle operation with secondary soreness in his SI. On vet’s advice I’ve had ‘wedged’ and padded shoes put on his hinds to correct the angle of his pedal bones while he’s recovering – which in turn should help his SI. I was about to try taking his shoes off (plus install a small track, feed hay with no rye/clover, no grains etc) when we discovered his stifle problem. I’m concerned that when the ‘wedges’ eventually come off that there will be a period when the pedal bones will be angled upwards again while waiting for the digital cushion and heel to strengthen and grow – and provide the same angle that the wedged shoes currently are – and that would then very likely make the SI out of kilter. I’m really enjoying reading your posts – fun but loads of stuff to learn too! I wonder if you have any thoughts on my horse’s situation please.

    • Hey Bernadette,

      Yes, you will have a period where the heels are too low. That’s a common issue when a horse has SI problems. I’d suspect the SI issues are the root cause, rather than secondary. (or at least long term SI issues cause stifle problems, hock problems and low heels to develop)

      The heels will be too low for a while, but a hoof with poor heel structure put into high heels isn’t a long term solution either. Just as your horse will need a recovery period from the stifle op, he’ll need a rehabilitation period for his hooves too.

      You can put a wedge pad in boots, or even just EPS therapeutic pads in boots can be a great way to help the hooves. Not only will they help develop the digital cushion and lateral cartilage, they’ll mould to the hoof and probably create a little wedge of their own.

      Do you have a good bodyworker and barefoot knowledgeable hoof care practitioner to help you?

      • Thanks Debs. That’s really helpful. It hadn’t occurred to me that the SI problem might have caused the low heels – interesting … and good to know. Agree that the wedge shoes aren’t a long term solution (and very expensive). He’s got eight weeks box rest, then six months gentle, progressive rehab. I don’t know much about horse boots at all – is there a particular kind you can suggest where I could put a wedge in which will allow his heels and digital cushion to grow please? If there’s a boot which would correct the pedal bone angle and support his SI and at the same time that would be amazing. Genius idea! I’ve got lots to learn. I’ve got a good bodyworker (a vet who specialises in rehab / physio). I’ve ‘just’ got my farrier looking after his feet at the moment but he does seem to know quite a bit about barefoot (eg my other horse is recently barefoot and is wearing away her hooves by being in work on hard surfaces and rather than do an unnecessary trim he said she didn’t need it) and so far is proving to be a good ally. Thanks again for your help – very much appreciated.

  • Hi my horse is Andalusian. He has good feet except he steps short with his near fore and wears his heels right down on his off hind. We have taken his toes back at each trim but it isn’t improving really. I used cavallos with pads inside for hacking as it’s a stony ride. He can manage without although he picks his way more carefully and I get worried about bruising and abscesses. He has had any though. It’s mainly on the outside of his off hind heel and he wears it right down to the heel bulbs. He still doesn’t get a heel strike at all in the near fore. I believe there is history of some arthritis in the joints in that foot. Many thanks Susie

  • I just re-read the article and Q&A. It’s amazing how much more I pick up every time I come back to your information. We’ve gotten past the toes first landing and the discomfort on sand and are headed in the right direction. Thank you.

  • Excellent series! Yes helped my understanding greatly. The stuff about “flares” and tubule direction in part 1 was a revelation to me

  • Trying to correct underrun heels. Need to know is walking the best excercises so I don’t hurt tendons due to long to no break over.

    • Walking in hand is great. It’s well known that movement is key to healthy horses, but this seems to have been misinterpreted to mean ‘lots of hacking’. I’ve found I can get really good improvements from just 10 mins walking a day in hand on a hard surface. If you need boots and pads, they can help too.

      Doing lateral movements on a soft surface can help too. Underrun heels are all about the soft tissue in the back of the foot being too weak. Lateral movements will help to strengthen this.

      • Thank you, I will do more walking in hand. He is in boots and pads when out of his paddock to protect his heels. We are getting lots of rain which is not helping his feet. I am hoping for more improvement once we are more drier. Thank you again!

    • I work to address the health issues in the horse, use boots and pads where necessary to protect new growth and weak internal structure, and stimulate good healthy structure. I make sure the diet and gut function is as good as we can get. I often reduce the level of work the horse is in, depending on how much work he was in, and how bad the heels are. If healing is the priority, then rest is good. If strengthening is the priority then exercise is good. If there’s a gait abnormality then I’ll have that looked at too. Or if it’s caused by saddle fit, I’ll get that looked at.

  • Your part 3 article cites heavy heel landings however, my horse is landing toe first thus causing his underrun heels. My trimmer has me riding him in boots that encourage a heel first landing. His front frogs have always been skinny. We are waiting to see if he improves with the boots.

    • Yes it can happen, it depends what else is going on. If there is heel pain you’ll get a toe first landing. The heels can also collapse due to lack of stimulation. So many ways it can go wrong… 🙂

  • Very clearly explained thank you . I have a 13 yr old ex NH mare who has not been ridden since I got her at 5 years , out of training . Shortly after I got her , she had an accident in the field which left her with fractured withers , she has never been comfortable to be ridden since . I have done ground work with her and she has access to a field or track 24/7, depending on how wet it is . She is regularly trimmed and is on low sugar forage and a mineral balanced diet and has been barefoot now for 7 years . She still has underrun heels although I have always tried to keep her toes back . Have I not backed them up enough do you think ? We now have found a reliable and sympathetic farrier to trim for us ( arthritic back finally gave up ! ) and he said it can be that some thoroughbreds have just ” the feet bred out of them “. Do you think that is the case ? She is very well bred with good conformation but does have longish pasterns . Can that contribute to underrun heels or is it not connected ?

    • I wouldn’t blame the long pasterns or the breeding in the first instance. I’d look for gut problems first, and any connected inflammation. It’s possible the broken withers has caused a gait abnormality that results in underrun heels, but… It’s such a common problem in TB’s, I think I’d look to the most common causes and solutions for TB’s which tend to be gut. I don’t think they’ve had their feet bred out of them as such, I think the way their develop as a foal, leaves their gut under developed, so even when you feed the ‘right’ things, sometimes you don’t get what you need, so you need to be that extra bit ‘perfect’

  • Hi, I’m struggling to know if my QH has under run heels or not, plus flair on his front feet. Backs seem good fronts not do much. My trimmer has s background of my Dad taught me on the ranch and no professional certificate – not that that makes much difference sometimes. Would love to be able to send in photos and compare against others photos for folks to consider. Love the blog!

    • I’ve emailed you, if you want to send me photos, you can email them directly in a reply 🙂 Flare and underrun heels often go together.

      I’m glad you’re loving the blog 🙂

  • My mare has under run heels. She has never been shod, has plenty of walking out in hand, has 24hr hay, lives on a track system 3/4 of which is hard core, is fed a small amount of hard feed (barefoot friendly) but I have also tried 6months without this which made no difference to her feet. She can self select willow, hawthorn, rose hip, birch, thistle, gorse and many many more. She is trimmed every 2 weeks but there is no improvement. I decided to boot her on the track a few days ago and intend to fill the sole part of the boot with sheeps wool to stimulate the sole/frog. Will this help? Anything else you can suggest. Really pulling my hair out as I feel I have tried everything including spending thousands on creating the track!!!!

    • You seem to have all the obvious stuff covered, so the problem is likely very specific to your horse, which makes it difficult for me to be helpful through the medium of a blog. I’ve never tried sheeps wool as a pad. The ideal pad is able to absorb excessive pressure, but also deliver enough pressure to stimulate the hoof. I love these pads

      Why is she trimmed every 2 weeks? That’s a pretty short trim cycle, is she growing fast?

  • Hi there,

    Thank you for your informative article. You mention that three of the four ways to correct underrun heels is within our control. Do you have any suggestions for stimulating the frog and digital cushion on a horse who is landing toe first to avoid pressure on heels which are underrun? Horse is barefoot, turned out 24/7 and taken for walks about 4 days a week. Diet is correct and balanced.

    • Yes, boots and therapeutic pads help a lot
      Keep them off sand if there is a deep central sulcus (if the bit in the middle of the frog looks like a slit – it should look like a thumb imprint)
      Shoulder stretches. A toe first landing causes the shoulder to lock up. A tight shoulder causes a toe first landing, so once you have a toe first landing, it’s a self perpetuating problem. I’ve seen a hooves absolutely transformed by doing nothing more than a shoulder stretch. (well – the diet was already sorted, at that point adding in the should stretch got amazing results.)

      • I also have a mare that has underrun heels and elongated hooves from 3 years of bad shoeing. I now have her barefoot, am trimming her toes back to where they should be. She lands toe first too. Thinking back she has probably been doing this even when she still had shoes on. I found that when she wears boots (I don’t have pads yet), the landing is slightly better, where she lands more often flat. What shoulder stretches do you recommend ? And would the pads add to the improvement ? Can you get these pads in the US (I actually live in Costa Rica where you cannot get anything, but can have friends from the US bring stuff down for me). Thank you. I love your blog.

        • Yes, the pads would help. They would help put some pressure on the heel structures to strengthen them, they’d also absorb some of the extra concussion caused by a toe first landing. You can get them in the US, but I don’t currently know a supplier to recommend. If you find one, please let me know as I’m often asked.

          Most commonly I’d use a simple shoulder stretch to pull the leg forward. Make sure your posture is good and supporting your back, and you’re breathing properly. Don’t pull the leg with your bodyweight.

            • I often see over developed hamstrings with underrun heels in hind feet, but I don’t think the tight hamstrings are causing the problem. I’d look more at lumbar, glute and SI problems, and by ‘look’ I mean ‘point at it and refer to someone who knows more about it than me’ 🙂

  • First, love your blog, its a great balance (pun intended) of fun and great info. Do you have any pics of under run heels where they have overlapped? I think that is what I’m dealing with but I can’t find any visual reference and text descriptions just make my head spin. Its like the ‘seat of corn’ and ‘bars’ don’t exist on this horse! Thanks and keep up the blogging!

    • Yes, I do. I’ll dig them out. I found that they don’t photograph very well. 2 horses I’ve been working with recently have both grown out exactly what you’re describing. I spent ages trying to get a good photo but it never really showed what I was trying to show. Even swearing at the camera didn’t help! The folded over bit was still folded over, but the new growth coming through was at a much better, straight angle. When I had enough growth, I trimmed off the folded over bit. If you can get the ground reactive forces going in the right direction, the hoof responds by growing in the right direction.

      I do like a good pun, so thanks for that :)

  • I have a 6 yr old quarter horse whose farrier let him get way under run, causing flair and eventually a horrid center crack up to his coronet band on both front feet. One has heeled the other is taking extensive repair and time. Changes carriers and this guy hot shoes him, and is standing him back up. His flair is disappearing, but one hoof is still fighting the crack. He widened it, put a drain in, filled it in and out a metal piece over top. He is still lame but not nearly as much. What can I do to keep a farrier from letting my horses get under run again? They won’t listen. This new guy is very good but expensive. I can’t afford to use him on my whole herd.

  • I agree with Sue, I still don’t get how to trim and correct this. I know two horses off the top of my head that are underrun.

  • Hi there
    I have an ex racehorse with underun heels he’s had shoes off for five weeks now. In fact underun and overlapping. I’ve taken the overlap off so I can now see the triangle bit (seat of corn ..?) whereas I couldn’t before. Toe is back to just infront of white line. Was it correct to take the overlap off? I hope so….seemed the correct thing to do.I haven’t gone harshly just mms. To be honest there isn’t much foot anyway. He’s getting mms of good growth from the coronet . Exercised with boots,turned out for 10 hours (he can’t cope with more as not used to it yet)
    Good nutrition and a big dose of optimism from me.
    I am not a trimmer but have been doing my own horses and many transitions for about 15years.
    I hope you don’t mind advising me.

    • Hey Rachel,

      I don’t mind advising, but it’s hard to do (well) without being there 🙂 If your horse is comfortable, then you probably haven’t gone too far wrong. Some methods try to get that triangle by taking the heels low (usually too low) and I find this causes a whole pile of problems. You often have to do the best you can with what you’ve got when it comes to underrun heels as often you don’t have much foot to work with.

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