Written for KWPN-NA by YK Ambassador: Mara Santiz
Arena footing has been a subject of contention for many years. New arenas with synthetic footing have become more common over the last few years, making them easier to maintain, but are they the best choice for the health of our athletes?
There are three general phases per stride in a horse: landing, loading, and rollover.
Landing: the hoof strikes the ground, potentially slides a bit, and comes to a complete stop
· All of the force is pushing down into the ground and horizontally across the surface of the footing
· Every time the hoof lands the bones in the horse’s leg collide
· The hoof hitting the ground creates shockwaves throughout the ground and the horse’s leg
Loading: the hoof holds the full weight of the horse and is flat on the ground
· The fetlock sinks, in some cases it is almost parallel with the ground
· The fetlock, the suspensory ligaments, and the other tendons in the leg provide support and absorb shock
· Pressure on the frog increases blood flow
· The amount of loaded weight depends on the movement the horse is performing
Rollover: the heel rotates forward off the ground, and the breakover occurs
The footing for any discipline is important to the health of the horse, however the footing for dressage is arguably the most important. Whereas jumping is the same repetitive movement, dressage needs an arena that can withstand collected work, extended work, lateral work, and rotational work.
When a horse is asked to perform collected movements such as piaffe and passage, there is a great deal of flexion seen in the horse’s back and hindquarters. The footing needs to support more weight in one location as the horse sits on his hind end without preventing the horse sinking down too far. During this collected work, the horse is in one place for a longer period of time, so the footing should have a lower shear strength. This means that the horse’s hoof should be able to sink into the top layer of the footing easily.
Extensions are just as important as collection in dressage. During the extended trot or canter, there is more suspension in the gait which leads to a greater impact every stride. The footing needs to be soft enough to support high impact even though the shear strength is higher in order to avoid hyperflexion of the limbs during the loading and rollover phases. The hoof cannot sink too far into the footing or the tendons and ligaments can become damaged at such high impact rates. When the hoof comes into contact with the ground, the vibrations from the impact need to be distributed evenly throughout the leg and the footing.
When a horse performs lateral movements such as shoulder-in and half-pass, the shear resistance, or the frictional support, of the sand must not be too high. The horse’s body is positioned in an unnatural way as he moves laterally, and a high shear resistance can cause the footing to be too “sticky” for him to push off easily. If that is the case, there is a higher injury risk as the horse’s hoof is left behind in the footing and the body keeps going, straining the muscles.
The last movement type to consider is rotational. In the middle of a pirouette, all of the horse’s weight is on the outside hind leg. The footing must withstand all of the weight while still allowing for smooth rotation. Less shear resistance is needed so the limbs are not subject to torque.
Based on the above information, a dressage horse requires several things as far as the footing:
· Allows the tissues to load evenly during the landing phase
· Provides firm support during the loading phase, but also must absorb shock
· Enough shear strength so there is little strain on the tendons and ligaments during the rollover phase, and so that extreme hyperflexion is prevented
– The shear strength must also be low enough to aid in vibration absorption on impact
· Low shear resistance to avoid body and limb torque during lateral and rotational movements
A jumping horse also needs to have proper footing
· During take-off, the footing must be able to support all of the horse’s weight in one spot
· Low shear resistance to avoid limb torque as the horse takes off
· During landing, the surface must be soft enough to absorb shock
· Enough shear strength to avoid hyperflexion upon landing, and protect the DDFT in the first landing limb
Footing for reiners
· Provide low shear resistance to avoid body torque on tight turns and to allow the horse to slide during stops
· Low shear strength so the hoof can sink into the top layer of the footing and support the horse’s entire bodyweight as he comes to a stop
· Grass: difficult to maintain due to weather conditions
· Rubber and woodchip: can cause injury due to lack of consistency, tends to be slippery, woodchip layer below the primary surface can increase shock absorbency
· Wax (synthetic): tends to be too sticky, and the shear resistance is far too high
· Sand: there are several different types of sand that can be used
Fine sand with sub-angular particles is likely the best manufactured footing. The sand particles have a high elasticity to help return the sand to its original state. Typically a binder such as wax or another polymer is added to the sand to provide proper shear resistance to assist in lateral and rotational movements. The binder can also help to create a higher shear strength to absorb vibration and shock during the loading and rollover phases. A binder will help the sand to be malleable enough that it provides support to the frog, which will stimulate a proper amount of blood flow without being so soft that it adds too much pressure.
By building a proper arena with good footing, we can help keep our athletes healthy and sound.