Saddle + Half Pads - The effect on race saddle pressures and gallop kinematics
/![[Headline]Scientific research quantifies the impact different pads have on the horse’s performance[Standfirst]The use of pads under the saddle has been common for years, but now scientists are using dynamic testing technology to discover how well th…](https://images.squarespace-cdn.com/content/v1/517636f8e4b0cb4f8c8697ba/1608647929581-FNZB6TSD1YAKJRBU9W7G/OPENING+SHOT.jpg)
By Dr. Russell Mackechnie-Guire
Scientific research quantifies the impact different pads have on the horse’s performance
The use of pads under the saddle has been common for years, but now scientists are using dynamic testing technology to discover how well they really work
In everyday yard situations where multiple horses use the same saddle, putting one or more pads under has been seen as a way of providing cushioning and comfort for the horse, or even relieving pain. However, there has never been any research in racehorses to demonstrate whether this reduces saddle pressures or provides comfort. Furthermore, there is limited scientific evidence to suggest which type of pad is most effective.
A recent study suggests that, depending on the material and design, using a pad beneath the saddle might not always achieve the desired pressure-relieving effect. And using multiple ineffective pads under the saddle might not only be a waste of time and money, but it could potentially cause areas of high pressures, compromising the horse’s locomotor apparatus and affecting race performance.
Peak pressure of more than 35kPa were recorded in two of the three pads.
Peak pressure of >35 kPa can cause compression of the capillaries, leading to soft tissue and follicle damage (ischemia) which, in extreme or prolonged cases, results in white hairs, muscle atrophy, skin ulcerations and discomfort.
A recent published study evaluated saddle pressure distribution in sports horses using pads made from sheepskin, viscose gel and a medical-grade closed-cell foam. When using a gel pad, the peak and mean pressures increased in the front region of the saddle in trot and canter. This is possibly due to the gel’s lack of ability to dissipate shear forces compared to wool or foam.
Similar findings were seen in a pilot study of thoroughbreds galloping at half speed over ground. The same dynamic testing was used (see Technology & Anatomy panel) to compare the forces and peak pressures under polyfill pads, as well as viscose gel and medical-grade closed-cell foam. From the initial trials, the overall forces recorded were significantly higher than those seen in the sports horse study. This seems reasonable, given the difference in locomotion and speed (see Speed & Force panel).
Preliminary findings show the forces were 75% lower, and peak pressures were 65% lower under the medical-grade closed-cell foam pad than those recorded under the gel pad. Interestingly the polyfill pad, which deforms to the touch, reduced the forces and peak pressures by 25% and 44% respectively compared to the viscose gel pad.
The role of the pad is to act as a dampening layer between the horse and the saddle, reducing pressures and absorbing the dynamic forces which occur during locomotion.
Based on findings from the sports horse study, and initial findings from the racehorse study, it appears that the medical-grade closed-cell foam pad is superior in its effectiveness at acting as a pressure-reducing layer between the saddle and the horse.
Pressure to perform
A shaped saddle pad with a midline seam is less likely to draw down on the spine
Reducing saddle pressures improves gallop locomotion. Horses will still perform when asked, despite areas of high pressures induced by the saddle and pad; but they develop a compensatory locomotor strategy in an attempt to alleviate any discomfort.
To increase speed, a galloping horse will either increase stride frequency or increase stride length. Both mechanisms can be used, but the horse will have a natural preference. Published pressure studies have shown that stride length is increased when saddle pressures are reduced. Now, new research is underway quantifying whether a stride frequency approach, which has higher peak forces, could be a compensatory strategy in response to discomfort caused by pressure.
Forces are influenced by speed and weight and are produced when the hoof comes in contact with the ground. At racing speeds of 38 mph, the hoof hits the ground approximately 150 times a minute. Stride frequency is an important consideration because a study has suggested that horses have around 100,000 gallop strides before the soft tissues fail. Therefore, any reduction in loading cycles (number of strides) could potentially help reduce injury risk.
Harder, faster, longer
Every stride impacts the horse’s joints, causing wear and tear (see Speed & Force panel), so fewer longer strides is the preference for optimum training efficiency. Although horses have a naturally imprinted option, the pressure studies demonstrate that they switch between the two in response to certain extrinsic factors, such as high saddle pressure.
Our task as trainers is to optimise the horse’s locomotor efficiency by removing any impediment that might force it to adopt the shorter-stride compensatory gait. We speculate that equipment which increases pressure (such as an unsuitable design of saddle, bridle, girth or saddle pad) will be counterproductive because it may encourage an increase in stride frequency and compromise natural locomotor efficiency.
Contouring is key
In both studies, the saddle pads that were designed to follow the contour of the horse’s back and withers performed better than those that were flat with no shaping. Furthermore, pads with a midline seam connecting the two sides were able to maintain traction and position, providing spinal clearance even at speed.
In contrast, pads that were flat without any contouring or with no central webbing seam were observed to slip in response to the horse’s movement, drawing down against the spine under the saddle. This was seen even when the pads were pulled up into the saddle channel before setting off.
Quality vs quantity
In an attempt to improve comfort, it’s standard practice to use multiple pads under an exercise saddle. However, adding more shapeless padding can lead to instability and potentially saddle slip.
This feeling of instability can encourage the jockey to overtighten the girth in an attempt to keep the saddle still. One study demonstrated a relationship between increased girth tension and a reduced run-to-fatigue time on a treadmill, indicating that girth tension can affect the breathing of the galloping horse.
In addition, bulk under the saddle puts a feeling of distance between the horse and rider. This compromises the close contact feel and balance all jockeys strive to achieve and hinders the lowering of the jockey’s centre of mass relative to the horse.
Age concern
It’s worth noting that the ability of a material to absorb pressure can be significantly compromised with use and washing, as well as changes in climate. As some materials age, they degrade and loose any initial shock-absorbing qualities. For example, wool loses its ‘crimp’ over time and becomes less effective, so a well-used wool pad may not absorb as much pressure as a new one. …
