THE SPECTRUM OF USABILITY

The Spectrum of Usability (SoU) is an essential tool used within AEP. It is the responsible way to protect the horse when shoes are removed and provides the guidelines to allow us to correct the structures without exceeding the ability of the hoof. It is an on-going reference for the use of both the AEP, owner and vet.

It has ratings from one to ten, ten being the Perfect Hoof. Each structure of the hoof is marked accordingly enabling an overall assessment to be made, the level of work that can be undertaken and to formulate a conditioning programme including any environmental changes that may be required.

A Spectrum of Usability will also take into account the environment that the horse is kept in and that may influence the overall score regarding the potential within that environment for the hoof to be rehabilitated/conditioned. Weight of horse and rider and fitness level of the horse are another example of how the score may be influenced.

As a guide a rating of one or two is given when a structure is very weak and structures may be deteriorated to the point of being missing. See Examples below.

A rating of three or four will show structures that are all visible but in poor condition.
A rating of five or six will show correct structure without any major imbalances.
A rating of seven and above is not that common but does indicate that the hoof is in very good to excellent condition.

A HEALTHY HOOF demonstrating the non-invasive High Performance Trim and rated as a 7-8 on the Spectrum of Usability This horse regularly completes 3-5 hour long rides at varying speeds and over mixed and at times demanding terrain. Turnout comprises of a mix of pasture, sand and hard-standing over a 24 hour period.

THE FROG: should be in proportion, 50-60% wide as long with no sign of infection with even exfoliation.

HEELS OR ANGLE OF THE BAR: The Heel or Angle of the Bar should display a good surface area located close to the widest part of the frog and very slightly (credit card depth) higher than the Frog with a smooth connection to the bars.

BARS: Straight with a slight angle opposing the frog and blending into the sole

TOE: The toe at ground level should be symmetrical to the curve of the coronet band. Within AEP the toe plane should be even with the heel plane.

SOLE: The Sole should be smooth with concavity the deepest point being at the Apex of the Frog

THE WHITE/GOLDEN LINE: This should be a shallow crease, free from infection and bruising containing a small amount of grit to aid traction.

WALL : The wall is made up of the outer wall and inner wall. A close up view helps define this more clearly.

THE OUTER WALL: This should be free from cracks, bulges, growth rings and flare and a little thicker at the toe.

THE INNER WALL: This should be have even thickness from toe to heel and buffers energy on impact and acts as a buffer to dissipte energy on impact protecting the internal structures from trauma.

EXAMPLE OF AN UNHEALTHY HOOF - Rated as a 2 on the Spectrum of Usability This horse until recently was shod but due to lack of structures the shoes will not stay on and as a consequence can no longer be ridden. It is turned out on pasture 24 hours a day in the summer and during the winter stabled at night.

This is a very vulnerable hoof, but not an uncommon sight and would require a major change in living conditions and a high level of owner commitment and participation to restore it back to health.

It has been rated with such a low score for the following reasons:

The frog is poor, small and withered.
There is severe fungal infection of the frog, central sulcus and up into the bulbs of the heels.
The whole hoof is very contracted.
The inner wall is virtually lost and cannot protect internal structures from energy on impact.
The white/golden line is barely visible and there is little surface area at the angle of the bar.
The whole hoof capsule has migrated forward from where the widest part of the frog should be and every structure is weak and lacks surface area.
The toes are very long and the sole lacks concavity and exfoliation.
Being the front hoof it should appear round rather than long and narrow.

Within Applied Equine Podiatry this range of pathologies is known Deformed Hoof Syndrome (DHS).