How an eye on equine entheses can beat navicular

Images © Christoph von Horst, PhD, DVM.

Greatest scientists are always artists as well.” – Albert Einstein

Einstein’s completed quote is, “After a certain high level of technical skill is achieved, science and art tend to coalesce in esthetics, plasticity, and form.

Entheses6The scientist who completed this “masterpiece” is undoubtedly an artist but the real beauty of the picture is that the new generation of research, science and art coalesce for the prevention of injuries. Dr Betsy Uhl, DVM, PhD, is preparing the next Science of Motion International Conference, to be held October 3 and 4, 2015 at the SOM training center, and this beautiful illustration demonstrates how the study of “entheses” – which is the name given to the areas where tendons are inserted on bones – can prevent the development of navicular syndrome.

As you know, the science of motion does not believe that riders have baby brains that have to be fed with baby food. While the general consensus is repeating infantile theories, we provide instead pertinent information, often the cutting age of equine research studies. Other studies are published but the superiority and trademark of the Science of Motion is the practical application. We are not afraid to question traditional beliefs in the light of new knowledge. Indeed, updating riding and training techniques to advanced scientific discoveries greatly further riders’ and trainers’ ability to prevent injuries.

New equine research studies focus on preventing the disease and the study that Dr Uhl is developing is going to blow the minds of those who attend the 2015 Science of Motion International Conference.

This is the illustration of a damaged navicular bone. There is no need to discuss the fact that preventing such damage is a thousand times more efficient than trying to deal with an affected distal sesamoid bone.
A damaged navicular bone.

Pictured at left is an illustration of a damaged navicular bone. There is no need to discuss the fact that preventing such damage is a thousand times more efficient than trying to deal with an affected distal sesamoid bone.

Preventing involves the capacity of interpreting early signs and the new generation of  “entheses” studies provides amazing perspectives. Entheses is the name given to the area where elastic structures such as tendons, are inserted to bones.

Any common sense in physics allows understanding that the connection between a solid structure such as a bone and an elastic structure such as a tendon is submitted to intense and specific forces. The  attachment of the deep digital flexor tendon on the coffin bone is quite large. On the accompanying picture there are dotted lines around the deep digital flexor tendon. The oval shows the area where the deep digital flexor tendon inserts on the coffin bone. Below that is an enlarged view of the area where the deep digital flexor tendon inserts on the bottom of the coffin bone. This area is indicated by a discreet triangle.

Dotted lines surround the deep digital flexor tendon. The oval shows the area where the deep digital flexor tendon inserts on the coffin bone.
Dotted lines surround the deep digital flexor tendon. The oval shows the area where the deep digital flexor tendon inserts on the coffin bone.The triangle indicates the area where the deep digital flexor tendon inserts on the bottom of the coffin bone. The triangle indicates the area where the deep digital flexor tendon inserts on the bottom of the coffin bone.

All the area below the navicular bone is loaded with receptors. There is a very large number of sensors, which is understandable since a great percentage of the forces coming from the body down to the hoof through the limb is acting on the heel area. On the next picture, the area with the very large number or receptors is surrounded by an oval. One member of the team, who is not a rider, theorized, “This is how the hoof control the gaits?” Dr Uhl, who is an advanced rider reacted immediately placing her fingers like a hoof capsule and pushing energetically her hand down. Gravity is not acting from the hoof up into the leg. Gravity is acting downward, from the body mass down to the heel through the bony column of the limb.

The large quantity of sensors is there to measure impact forces. The dark red area that you can see just under the navicular bone is an area of the deep digital flexor tendon that is damaged by intense stress. At this point, the navicular is not damaged and this is where are the value of these entheses studies. The pain is there, but x-rays will not show yet, navicular change. The horse will then likely be diagnosed as having a bruised heel. It will be given bute, advised some rest, or put back to work.

The warning is there.

There is a kinematics abnormality of the front limb that is inducing excessive stress in the navicular area. If the kinematics abnormality is not addressed, the next step will be the development of navicular syndrome. At this point, the bone is not affected and the recovery can be total. A few months later, the kinematics abnormality will still have to be addressed but the damage on the bone will render the rehabilitation more difficult.

In his study on dancers and musicians, Boni Rietveld wrote that dancers know their body and watching them practicing a movement and identifying the source of the kinematics abnormality allowed identification of the site of damage before advanced technologies could even show it.

Horses express pain the same way but primitive riding and training techniques dismiss the information as behavior. When I saw the damage on the deep digital flexor tendon immediately under the navicular bone, I had in front of my eyes a suspicion that was in my mind for years. I never truly believed in the diagnosis of bruised heel. I saw the discomfort lasting for a long period of time and not truly responding to drugs and hoof care. When I was asked to deal with such problem, I always looked for the kinematics abnormality, identified the source and focused on correcting the root cause. Of course proper functioning of the hoof capsule is necessary. In fact, one of the speakers of our 2015 international conference is a very talented and sophisticated farrier who is going to explains and demonstrates how the hoof works.

For the members of the In-Hand Therapy course who have watched our case study on navicular syndrome, one of the five horses, a paint horse, did not show navicular changes on radiographies but exhibited the kinematic abnormalities that have led other horses to the disease. We approached the problem as if it was another case of navicular syndrome and we restored proper limb kinematics by identifying and correcting the root cause. The horse became sound and never developed later in his life any navicular issue. This horse was very probably a case where the deep digital flexor tendon was damaged as in the picture, but we corrected the kinematics abnormality before it started damaging the distal sesamoid bone.

Coming soon: Part two – the explanation of Entheses

Register here to learn more about the 2015 Science Of Motion International conference.

Jean Luc Cornille

Jean Luc Cornille M.A.(M.Phil) has gained worldwide recognition by applying practical science to the training of the equine athlete. Influenced by his background as a gymnast, Jean Luc deeply understands how equine training can be enhanced by contemporary scientific research. A unique combination of riding skill, training experience and extensive knowledge of the equine physiology enables Jean Luc to "translate" scientific insights into a language comprehensible to both horse and rider. This approach has been the trademark of his training. - read more about Jean Luc

10 thoughts on “How an eye on equine entheses can beat navicular

  • February 9, 2015 at 7:04 am

    i have a 24 yo appaloosa with severe navicular that went through all the “traditional” shoeing, drugs, pads etc. my vet is shocked to see him still above ground. I was very close to euthanizing him whwn i came across the barefoot mustang model of trimming. That was his saving grace really and he sometimes wears boots with pads on hard/frozen ground. My question to you is that do you think there could more done to support the lack of heel through trimming? He now has started to stand with his hind legs stretched out? Not sure if he’a trying to take pressure off his front feet or not?

    • February 9, 2015 at 3:38 pm

      Hi Laurie. reducing the load on the forelegs is always the first and important step. A hoof grows in relation to the forces. By educating the thoracolumbar spine to better convert the thrust generated by the hind legs into horizontal forces, forward movement, and vertical forces, balance control. You can reduce the load on the forelegs and correct the hind and front limbs kinematics. What you notice with the hind legs is an adaptation to vertebral column dysfunction which is itself how the horse deal with the discomfort of the forelegs. There is no formula. This demands a sound analysis of the horse movement. If you are interested by the concept, the first step would be sending us a video of the horse in motion, walk and trot and even canter if he is sound enough to canter. JLC

  • February 11, 2015 at 12:16 pm

    Hello, we have three year old quarter horse that is coming four. He came up sore a couple times in light work and we when we had him x rayed, it did not look promising. He has an amazing personality and is super athletic. We’ve had him on equibone. Is there anyway you can look at the X-rays?

  • February 11, 2015 at 5:00 pm

    most of those lamnesess can be treated & healed with the Low Level Laser Machine. I’ll do it free just to show U how it works. Or U can have Ur Vet. do it for a pretty penny. Either way , it works.

  • February 12, 2015 at 7:14 am

    Hi. I have a 13 year old appendix that was having front end lameness. Initial xrays didn’t show much. Coffin injections were done and he got some relief. Corrective shoeing was also done. He is still in egg bar shoes with a 2 degree wedge. When the lameness came back my vet did new xrays…a cyst was observed in the left navicular bone. At that point we opted to continue with coffin joint injections and corrective shoeing. In November 2014 the lameness returned. I did some research and asked my vet about Tildren. It had recently been approved by the FDA..we had to wait a few weeks to get it so in the meantime we did more coffin injections. Tildren was done 12-29-14. He has been sound since then. I know it takes months for the Tildren to work. Are there any other options? Thanks in advance!

  • February 12, 2015 at 10:31 am

    Contact us at
    and we are not user JEAN that says low level laser machine..that is not us we do not do that at all !!!

  • April 1, 2015 at 10:38 am

    So, because the symptom in the horse is sub-clinical when it doesn’t show up on an x-ray, would thermography be helpful in identifying the problem?

  • May 22, 2015 at 6:08 pm

    Hi Jean, I have a very complex case with a horse I rescued back in Oct because his was difficult to handle and labelled dangerous, in 2011 he was diagnosed with a small avulsion fracture in the origin of the impar ligament of the left fore but also small lesion in pedal bone at insertion of the impar ligament on right fore as well, the owners were told by the vets that he would never become sound again and they claimed loss of use, he had time off and did low level riding club until I got him out 2014, first thing I noticed was his walk, short strides with him hammering his front feet into the ground, we had no power from behind, he wasn’t able to go forward and the Physio was also worries about his SI, he had no glute muscle and he was very asymmetric, when riding him he just throw me off to the left and then the muscle didn’t develop on the left, the farrier Said he wears the outside of both front shoes so he’s not landing properly, he did improve but never felt that he was ever quite right and could possibly in low level pain so took him to the vets, he looked completely sound until under saddle and then shortened strides in walk, unable to bend to the left, he was x rayed and has mild crowded spine so we are doing straightness training to build up the right muscles in hand as well but last week he has gone horribly lame in front and behind and the vets didn’t want to listen to anything I have to say about the outside wear to shoes, what my Physio had said about SI and I’m desperate to get to the route of his problems as believe he has been in pain for a long time, I’m hoping you maybe able to help, advise on the best way forward, thanks in advanced. Sara


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