FOOTPRINT TRIM
By Cheryl Henderson
The footprint trim is a method that establishes the natural 1/3 2/3 balance to the hoof, by first finding the true baseline and the widest part of the foot called the fulcrum. Within the hooved foot is a sacred geometry that mapping using the baseline and the fulcrum line as a measurement guide proves consistent. The footprint trim will establish a natural balance toe to heel even for the beginning trimmer. Understanding how the internal structures work, the goal is to trim away excess wall and bar and create healthy balance to prevent interference to hoof mechanism. A simple gauge called the footprint ring has revolutionized the way we can trim by insuring a good balance toe to heel. Knowing how to use this simple method of mapping provides an outline on the foot that predicts balance before trimming.
The sole area has two constants that are recognizable and cannot be distorted by a hoof that is excessively long, flared, underrun or foundered. Knowing what, where, and why allows us to make a plan in the form of a map to trim correctly and do no harm while improving form. These two constants are the baseline, and the fulcrum line and they are used to establish the outside parameters of the map. The baseline is located at the back of the frog. It shows where the heel purchase should end either by natural wearing or trimming. The fulcrum line is at the widest part of the hoof and divides the hoof in half back to front.
To determine the natural 1/3 2/3 balance within the ring, the hoof map is divided into thirds from back to front. We know that the digital cushion from which the live frog grows and produces frog padding is 2/3’s the length of the natural footprint from the baseline. The front tip of the digital cushion attaches to the bottom rear surface of the coffin bone. It cannot be stretched forward, or out of place even in a hoof that has a long toe, chronic toe first landings or has been deformed as in founders with laminar wedges. This is the practicality of using the footprint ring as it will ignore frog padding and sole that is stretched forward of the true apex and determine the remaining 1/3 length of foot for an honest 1/3 2/3 balance for the internal structures.
Another method to find the true frog apex is to sight a perpendicular line from the front center of the coronary band to the rim of the hoof capsule. Then sight across the sole to the frog to establish the apex. The fulcrum of the foot is approximately ¾ inch behind the apex of the frog. All of this is good to know but, not necessary with the help of the footprint ring.
The fulcrum line is located at the widest width lateral to medial, dividing the quarters in half and is the point at the quarters where the front shape of the foot going outward, changes directions to the back of the foot going inward.
Part of the sacred geometry of the foot is that the length of the fulcrum line (side to side) and the length from the baseline to the top of the footprint establishing the toe are the same and determine the size of the ring dimensions for our map. Even though there are differences between the rounded front feet and the spade shaped hind feet the footprint ring will aid in showing where the toe is and what trimming is necessary. The difference will be that the rings rounded top that fits perfectly to the 10:00 and 2:00 positions in mapping the fore’s will only provide the length to the toe on the hind hoof. Our knowledge of hoof shape allows us to draw in the toe quarters in the spade shaped rear hoof.
Understanding that sole to the side of the frog does not stretch outward we can confidently mark the fulcrum. Detached space between the sole and capsule wall is created by flare bending the wall outward. Additionally, not factored in the fulcrums length is capsule horn and the white line which both develop; gaps, irregular thickenings or deficits created from disease, laminitis and founder, none of these alter the length of the fulcrum which is the measure of the soles width. The fulcrum is the critical measure to mapping the length of the footprint from the baseline to the toe because the foot can be deformed through elongation of capsule, sole and frog stretching beyond the natural 1/3 2/3 balance.
The sole between the frog and the quarters is neither stretched nor reduced by disease or flare. We can feel confident to use this width because what we see is an honest measure. However sole in the upper half of the footprint, can be pulled forward by several causes, most common is by a capsule with long toes and underrun heels known as forward foot syndrome (FFS), others are founder, laminitis, capsule flare, heel pain and disease.
The hoof, pastern and leg bones are connected by hinged joints that move back and forth not side to side. Because of this motion, as the foot strikes the ground at the baseline, the impact will be the initial weightbearing for the entire leg.
The descending heel crushes down into the ground surface pushing up the periople skin that can curl or become smooth at the natural baseline depending on the terrain it is in. Other clues seen are creases, color changes and different skin coverings that separate the protective periople skin and that of the frog padding. Unfortunately for the mini hoof when the heels are too long the periople skin will not wear at the baseline as in the larger equines. These little hooves will require measuring from the hairline over the collateral groove exit to establish heel height and baseline.
This is the beauty of using the footprint ring because it will clearly show you by mapping how much toe you will need to bring back in the trimming process.
Now that we understand the mechanics of the footprint trim and how it will help achieve the natural 1/3 2/3 balance to a hoof, learning the application of the footprint ring is very simple. Using round pipe clamps that are adjustable or even the cap off a jar if it fits to the parameters of the footprint trim can be used. The only specification to the size is that when placed on the baseline the circle can equally reach each side of the sole and be placed just over the soles edge at the fulcrum onto the unpigmented horn of the capsule. By taking the ring just past the fulcrum edges equally about 1/8th inch on each side, allows for an error margin. You should always error on the side of caution by allowing that tad of overlay off the footprint, which will also be extending the toe just a bit forward to allow ¼ inch for any toe length changes desired later.
The final process to the mapping is adding a second line arched and parallel 3/8th inch above the footprint line, like adding a seam allowance in sewing. A healthy wall thickness is approximately 3/8 inch wide. With ponies a bit less with drafts it will be thicker. Create a line to establish the outer wall. The area created between these two lines represents the capsule wall that would be there if the foot is balanced.
Once this 2nd line representing the outer dorsal wall is drawn in and there is sole and toe exceeding forward of it, rasp or nipper vertically back the excess to the mapped line. Then a bevel is rasped between the footprint line and the dorsal wall line for enhanced breakover.
There are many duplicates in teaching to trim that the ring validates, one that is commonly taught is the need to create breakover from 10:00 to 2:00 using 12:00 as toe center referred to by many as the mustang role. The ring happens to sit when placed correctly right at these two locations.
Many times when doing initial trimming the mapping of the true footprint will be very dramatic in that the arched line(s) are far back onto the visual sole. This can be a frightening distance in many long toed forward foot syndrome feet. Always re-evaluate the mapping and position at the quarters again to insure that it is accurate to the baseline and placing the ring correctly. The footprint ring is a gauge that will give you a healthy boundary to trim towards and do no harm while providing improvement to balance the hoof. A person trimming can use their own judgment to decide if they want to do a complete trim the first time or do a little trimming every day until the trimming balance is in the hoof.
This method seems very cookie cutter like and doesn’t take into consideration the variables of hooves. But, after you have tried the mapping in this manner you will find its accuracy is more correct then other trimming methods that leave the hoof out of balance toe to heel.
Years of study and expense to learn how to correctly trim from different educators can be simplified with huge savings in understanding just three things:
1. How to find the baseline
2. How to use the footprint ring
3. And be able to freehand draw the walls thickness at the toe. The rest is tool handling.
Remember we are trimming to the anatomical structures inside the foot. The advantage and benefit of the gauges used in the footprint trim provide a good plan for trimming a capsule to a form that is not interfering with the articulation of the joint or hoof functions.
The footprint ring which is amazingly easy and incredibly helpful costs about $1.30 at the hardware store. Look in the plumbing area for a pipe clamp; it is a simple metal strap with an adjustable width hinge to tighten or loosen a round shape.
Buy one based on your horses hoof size so that the ring will fit just over the width of the sole at the fulcrum. For average hooves buy the ring size 4 1/2 to 5 inch for mini's a 2 to 3 inch ring and the large draft hooves need 5 to 6 1/2 inch expansion.
This is the process and it will become very simple after a few times and your coordination to hold the ring on the hoof while marking the toe length and arch develops.
The footprint trims process of mapping:
1st Finding the baseline at the back of the frog:
2nd Set the clasp part of the ring just over the back of the frog at the end of the central sulcus leaving the ring right on the baseline.
3rd Open or tighten the ring a tad wider than the sole. Place equally over the white line sitting on the unpigmented capsule wall at the fulcrum line.
Quarters that have separation, flare or a deficit, you will need to visualize a tight connected wall out to about 1/16th to 1/8th inch beyond the rim of the soles edge.
4th With a marker outline the outside of the ring side to side. Remove the ring and what you see is the natural footprint outlined. This footprint line should be the upper white line area of a balanced hoof.
5th Freehand draw a duplicating second line, 3/8 inch above the natural footprint arch. The second line represents where the outer dorsal wall would be if the hoof was in balance.
The footprint trims method:
Everyone has their own preference to trim excess, wall, and heel and bar either in a sequence or just whatever excess comes to their eye to take first.
The way I do it, I first rule out sole deficit by marking the toe length and heel height. I will rasp or nipper the wall depending on how much is extending above the sole. I take great care to make sure the heel purchase is at the baseline. I remove any excess bar or diseased frog making a clear level area to put the footprint ring on. Lastly I use the footprint ring and establish toe length and if needed will freehand the second line in for wall thickness. I don’t have a favorite tool and use nippers, rasp or angle grinder to remove excessive toe length vertically up to the dorsal wall line.
Before I rasp a bevel for breakover between the two lines I re-evaluate the mapping, if correct, I add the mustang role to a balanced 1/3 2/3 foot.
The beauty of the footprint trim method is it protects us from being dissuaded by a stretch frog, toe flare, run under heels or deformity in the hoof capsule when trimming balance toe to heel in the foot. We can have trimming confidence in what we do, by understanding the two mapping constants of the baseline and the fulcrum.
