barefoot_Breakover

Heel-First Landing: A Good Indicator of A Balanced Trim

The barefoot movement and its veterinary researchers have come up with a reliable way to tell whether a hoof is well-trimmed overall.

Traditionally, people understood the importance of breakover to a horse's best athletic movement and to long-term soundness. Since the early 1900's, when cars replaced horses as the main means of transportation, this understanding got lost. The movement of most horses deteriorated as the "long-heeled" trim became the style in farrier schools. In recent decades, many horse-people have almost never seen a horse moving well. When I first saw my mare’s feet start to land correctly, I thought it looked "artificial"!

The indicator of a good trim is that when going on level ground, the front feet land heel-first. Just before the heel lands, you can see the foot "flip" forward as all joints in the leg go into complete extension.

In a horse with an imbalanced foot, the toe lands first, or the foot may land flat. With toe-first landing, you will see a little “wiggle” in the pastern bones -- you can almost hear them go "ka-chunk" -- as the horse puts weight on the foot.

(Note: The hind leg joints bend differently from the front leg joints, so that the hind leg lands heel-first almost irregardless of how the foot is trimmed. When I talk about how to trim a foot to get it to land heel-first, I am talking about the front feet. We don't trim the hind feet this way because they don't need it, except in the unusual situation where the toe has gone long-out-in-front; in this case we can use the trim method temporarily until the toe has been backed-up closer to the coffin bone.)

We can see the difference between heel-first and toe-first landing by walking the horse downhill and then uphill on a slight slope.

Watch your horse walking downhill. There is plenty of time for the front leg to extend fully before it reaches the ground. You will see the foot "flip" forward as every joint extends fully, and then the hoof will touch the ground heel-first.

Walking uphill to show what a toe-first landing looks like. None of the foreleg joints are in full extension -- there is not enough time for the leg to extend fully before the ground arrives. The toe touches first and then you will see a navicular-stressing "wiggle" or "ka-chunk!" in the pastern bones as the horse weights the foot.

Now, to discover whether your horse is "officially" landing heel-first or toe-first, watch him walking on level ground, and notice how the front feet are landing. Sometimes they land exactly flat, which is better than toe-first, but can be improved further by trimming as I will show below.

What is breakover?

Breakover is:

1) the moment in time when the foot starts to tip forward to lift off from the ground.

The heel begins to lift off the ground at the back end of the stride. (Here the horse is turning and breaking over slightly away from the camera.)

2) the position of a line across the toe, indicating where the foot is able to tip forward for liftoff.

Right arrow shows where the breakover is on a flat-bottom trim. If the toe is flared, breakover may be even farther out in front. Breakover is delayed and the leg only has time for a shortened stride and a toe-first landing.

Left arrow shows where the breakover line is when trimmed with a toe rocker and mustang roll. Note that the breakover is in the same position as in the shorter mustang foot (inner hoof outline) with naturally rolled toe. When breakover is in this position, the leg has time to swing all the way forward to full extension, and can land heel-first.

What does breakover have to do with heel-first landing?

The location of breakover determines whether the foot will have time in the forward stride to land heel-first, or not. If the toe is long-out-in-front, delaying breakover, the foreleg doesn't have time to swing far enough forward to land heel-first -- like walking uphill -- and will land toe-first instead; the entire gait is shortened.

Delay in breakover also causes forging (hind foot steps on the forefoot) because the forefoot doesn’t get out of the way in time for the hind foot to land on the same spot.

A wild mustang hoof (upper photo). Left arrow shows where breakover occurs on this naturally-worn foot.
A domestic hoof with flared toe (lower photo). Right arrow shows the breakover at the very front of a flared toe with flat-bottom trim.

Why do we want a correct breakover?

When the foot lands toe-first, the pastern bones must change from an upward curve as the toe lands, to a downward curve when the foot becomes weight-bearing.

When the foot lands heel-first, the pastern bones are already in a downward curve (full extension of the joints) and the curve doesn't have to change orientation when the foot becomes weight-bearing.

Everything about the horse's hoof works better when the foot lands on the ground heel-first. The hoof capsule flexes in such a way that you get the best shock absorption, the best circulation, and balanced wear. The digital cushion is tough and the frog and heels are wide; they are able to protect the foot from amazing amounts of hard work.

The horse's movement, when the front feet can land heel-first, is big and free -- some people describe it as "dressage-y."

When the foot lands toe-first, none of these things work well.

-- shock absorption is reduced,

-- there is less circulation inside the hoof (due to flexing differently),

-- the toe tends to pull forward so that the heels become contracted,

-- the hoof wears unevenly.

The horse's movement is short with the front legs "stabbing" the ground; the hind feet may forge (hit the front foot before it lifts off).

In addition, the "wiggle" in the pastern bones puts incorrect stress on the impar ligament, which holds the navicular bone in position. The impar ligament gets inflamed from constant toe-first landing. This inflammation, in Bowker's and Ovnicek's opinion, can lead eventually to "navicular syndrome" and/or coffin-joint disease.

What balance does the foot need to land heel-first?

In order to land heel-first, the hoof must have a correct toe-to-heel balance. The best proportion, in a front foot, is about 1/3 from breakover to widest part of the hoof, and 2/3 from the widest part to the heel buttress. In hooves that land toe-first, the toe section is typically longer (2/3) than the heel section (1/3).

A hoof balanced for heel-first landing.
The distance from the breakover line to the widest part of the hoof is shorter than the distance from the widest part to the heel buttresses.

An imbalanced hoof with long heels (which moves the buttresses forward) and a flared toe (which moves the breakover forward). The"widest part" stays at about the same position.
The distance from the breakover line to the widest part of the hoof is longer than the distance from the widest part to the heel buttresses.

My gelding's foot:
To show how a foot changes its proportions, here is a front foot, before and after using the toe rocker trim for about 2 months. The heels have spread 3/4 inch (2 cm) and the amount of toe in front of the frog has gotten shorter.
Note that the outline of the foot has changed from an oval to nearly round. (There is some flaring / stretched white line at the corners of the toe, where the breakover line crosses the toe wall. If I were doing this today, I would change to Pete Ramey's "white line strategy" trim.)

For an extremely oval foot with a forward-flared toe: One way to back up the toe quickly is to use Gene Ovnicek's toe rocker. I would suggest using this only for a few trims, until the foot has become rounder. Then I would recommend using Pete Ramey's "white line strategy" trim as shown on the "Do Trim" page to complete the transition process and regain concavity.

As we change the trim, the foot will start to shift from toe-first landing to heel-first landing when the proportion gets to about 1/2 toe -- 1/2 heel.

How to make a toe rocker:

The first time you do this, draw three lines with a felt-tipped marker pen to help you “see” the balance of the foot:

1) across the buttresses of both heels

2) across the widest part of the foot, about 3/4 inch (2 cm) or the width of your thumb behind the point of frog in a medium-sized horse; farther on a big foot, closer on a pony foot

3) across the back edge of the toe callus, about the width of your thumb ahead of the point of frog; you can often see where the toe callus starts to drop off into the concavity. (This line will be farther from the frog on a large hoof and much closer to the frog on a pony hoof.) If there is no toe callus, make the line a thumb-width ahead of the point of frog.

This third or "breakover" line, at the back of the toe callus, is where the naturally worn breakover would be on a free-living, naturally worn hoof (in relation to the coffin bone and the bony column of the leg).

I have marked this photo (actually it's a hind foot) to show the heel buttress line, the widest-part line, and the breakover line. I have drawn a slanted breakover line “as if” the horse wears off its toe at a slant (due to conformation or an old shoulder injury). The line goes through the spot at the edge of the toe callus, but it slants to match the horse’s own wear pattern, focused at the arrow.

With a hoof rasp:

1) First, shorten the wall to the edge of the sole, from the breakover line all the way back, including the heels.

2) Then, in front of the breakover line, rasp at a 15 to 20 degree angle, a flat surface across the whole toe. Stop when the rasp gets to your marker line.

Side view of hoof.
The line across the toe shows where the rasp makes a flat cut, across the entire toe, at about 15 – 20 degrees to the bottom of the foot. Arrow points at your marked breakover line. Rasp at the 15-20 degree angle until the rasp gets to the breakover line.

3) Finally, mustang roll (rounded bevel) around the bottom edge of the wall, including the sharp front edge of the rocker.

4)Shorten the bars to slightly shorter than the new wall level, and you're done.

5) I do not recommend using the toe rocker for more than one or two trims. Used longer, it prevents gaining concavity because you are not allowing the toe to grow longer underneath. A strong mustang roll will accomplish the same goal, maybe not as fast.

People are often worried about the fact that a toe rocker cuts into the toe callus. Gene Ovnicek points out: If the toe is flared enough to need a toe rocker (e.g. the horse is landing toe-first), then the toe has been pulled way forward. The toe callus is not directly under the coffin bone where it can protect the bone from injury.
When you get the flared toe out of the way, the foot and toe callus re-shape themselves very quickly to line up with the coffin bone, often within 3 to 6 weeks.
Caution: DO NOT put a toe rocker on a foundered horse, especially if the sole is bulging outwards. If the coffin bone is penetrating the sole, a toe rocker might expose the bone. Instead, back up the flare with a vertical cut (see Founder page).

Overall soundness
When a hoof is consistently landing heel-first, its entire physiology and its flexion are able to work the best. Trim problems that we have not been able to fix seem to resolve on their own.
-- A coffin bone that is sitting crooked inside the hoof capsule will level itself over several months without our frustrated efforts to "make it level."
-- "Unidentified heel pain" or "navicular" pain from an inflamed impar ligament disappears.
-- Contracted heels widen. In my two horses, all of the heels became 1/2 to 3/4 inch (1.5 to 2 cm) wider, measuring between the buttresses, within a couple of months. The outline, which had been oval for years, became nearly round.
-- The digital cushion becomes tougher so that the horse can go more comfortably on rough ground.
-- And the great delight: riders are reporting to me that "My horse now has big 'dressage-y' movement, he's such fun to ride!"
You can rasp a toe rocker on your hoof boots so your horse can land heel-first on trail rides. It should come back as far as the back end of corner toe clips on a shoe. This is because the thickness of the boot sole changes the relationship to the bony column of the leg.

	Watch your horse walking downhill. There is plenty of time for the front leg to extend fully before it reaches the ground. You will see the foot "flip" forward as every joint extends fully, and then the hoof will touch the ground heel-first.
	Walking uphill to show what a toe-first landing looks like. None of the foreleg joints are in full extension -- there is not enough time for the leg to extend fully before the ground arrives. The toe touches first and then you will see a navicular-stressing "wiggle" or "ka-chunk!" in the pastern bones as the horse weights the foot.

	When the foot lands toe-first, the pastern bones must change from an upward curve as the toe lands, to a downward curve when the foot becomes weight-bearing.
	When the foot lands heel-first, the pastern bones are already in a downward curve (full extension of the joints) and the curve doesn't have to change orientation when the foot becomes weight-bearing.

	A hoof balanced for heel-first landing. The distance from the breakover line to the widest part of the hoof is shorter than the distance from the widest part to the heel buttresses.
	An imbalanced hoof with long heels (which moves the buttresses forward) and a flared toe (which moves the breakover forward). The"widest part" stays at about the same position. The distance from the breakover line to the widest part of the hoof is longer than the distance from the widest part to the heel buttresses.