Does Girth shape affect my horse?

Girths come in all shapes and sizes

The choice of girth design, shape and size available on the market can be overwhelming, leaving many owners asking “what’s best for my horse?” There are brands that claim their girth can improve movement, make horses more comfortable and happier in their work. But do the girths live up to the claim? I feel claims like this have become a trend in the equine industry, as we are all animal lovers and want the best for our horses. Equine brands take advantage of this when marketing products to us.

Having worked on the ground as a yard hand, groom and horse owner, I have seen many types of girths used on different horses. In the last ten years or so, more and more anatomical girths have appeared on the market. However, not many have actual scientific evidence behind their claims. The first girth that comes to mind is the study on the high peak pressures that can be avoided using an alternative girth design (Murry, et.al 2013). In my previous blog post (here) I mentioned this paper and how the Fairfax firth greatly improved the horses movement and reduced the pressure under the horse. In this paper however, there was no mention of girth tension control- ie-how tight in kg each girth was set to. The first part of the paper looked into peak pressures under the horses normal girths in movement, and where they arose. It is interesting to note that the peak pressures were consistently found on the cranial edge of the girth, positioned caudal to the level of the olecranon process of the ulna (behind the elbow). The peak pressure occurred in every horse when the limb on the side of peak loading was in stance in trot and the contralateral limb protracted. (Figure 2 below) It would be interesting to know which girths they used for the horses “usual girths” in the initial part of the study and to what tightness they were all set, as it doesn’t cover this. Below is the differences in pressure under the Fairfax Girth ( Girth F)- which is designed to cut away from the peak pressure zone- and the horses standard girth (Girth S )(Fig3).

WOW saddles have developed a girth called the Free Space girth (pictured in fig. 4 below) The brand claims “The Sternum Plate makes the girth straps bridge the pectoral muscles and it is this lack of pressure that is the key to allowing the horse to engage by the use of an unimpeded Rectus Abdominus “  The Rectus Abdominus is a large muscle stemming from the chest and inserts at the 4th to 9th costal cartilages, runs the length of the belly, and attaches to the femur via the accessory ligament. This means that when your horse hunches its back to bring the hind legs under, one of the main movers is the Rectus Abdominus, which is used more than all of the other abdominal muscles combined (Duncan, 2021). So in theory, this is a muscle we do not want to impede in our horses. The girth is designed to avoid pressures behind the elbow. The WOW saddles website also shows a video of a horse with the girth along with a pressuring mapping image beside it. (Fig 5 below) Upon reviewing the video, I noticed that the horse moving is not the same horse used in the experiment testing the pressure mapping and there is no presence of the mapping pad/equipment. I would be very interested to know what tightness this girth was set to in kg and a comparison to other girths.

In 2021, WOW saddles tested this girth against other girths in a video, including the Scharf Freedom Girth. Scharf objected to the testing of their girth in the video and claimed their fitting instructions were not consulted prior to the testing and therefore was incorrectly analyzed. The Scharf freedom girth claims to be incomparable to other girths on the market, but I couldn’t find any pressure testing on their website. WOW saddles removed all instances of the video and issued an apology on the website. I haven’t been able to find any other studies or papers on this girth.

The research conducted by Bowers & Slocombe showed that girth tension itself pays a huge role in a horses performance (Bowers & Slowcombe, 1999). They looked at girth materials to find elastic girths had a significant impact on the horses performance, with elastic girths at 6 kg tension to have the longest run to fatigue time (RTFT) (Bowers & Slocombe, 2005). They also looked at width of girths and if this had an impact on the RTFT in the horses and tension. They used three standard sized 3-inch girths, an Elastic Girth, an American Elastic Girth and a Standard Canvas Girth. Two wide girths of twice the standard width were used; one composed of the same canvas material used in the Standard Canvas Girth and the other of the same elastic material used in Elastic Girth. Interestingly, the double width girths ended up showing a statistically significant result in reducing the horses RTFT and increasing tension, when compared to the elastic 3 inch girths. The elastic girth (wide) was 1.0-1.8 times higher in tension when compared to the elastic girth, at the peak exhalation point during exercise. When the horse is at full exhalation at exercise this would be the point at which peak tension would be found. The wide elastic girths still showed longer RTFT and lower tensions when compared to the canvas girths (standard and wide).

So what do we know? Tensions set over 6kg reduce performance, elastic girths have shown to improve performance, 3 inch width fully elastic racing girths were shown to be better than double width ones (Bowers & Slocombe, 2005) and that peak pressures appear behind the elbow while in trot (Murry, et.al 2013).

When I tested girths on riding school horses (Fairfax girth- cut away from the horses peak pressure area, the horse’s usual girth, a gel girth and a stud girth- tightened to 12kg) there was no statistical difference in the horses way of going between the girths. Looking at numbers alone, the gel girth did the best to improve the parameters. So at this time, general over tightening and material far outweigh the design of girths in affecting horses movement. Riders should look out for all elastic girths, keeping girth tension to close to 6kg and widths of close to 3 inches to not impede their horses performance.

References

BOWERS, J. and SLOCOMBE, R.F. (2005) “Comparison of girth materials, girth tensions and their effects on performance in racehorses,” Australian Veterinary Journal, 83(1-2), pp. 68–74. Available at: https://doi.org/10.1111/j.1751-0813.2005.tb12200.x.

Bowers, J. and Slocombe, R. (1999) “Influence of girth strap tensions on athletic thoroughbred horses“, Australian Veterinary Journal, 56-57

Duncan, K. (2021) Core strength and the performance horse, Horse Journals. Available at: https://www.horsejournals.com/riding-training/general/schooling/core-strength-and-performance-horse (Accessed: February 7, 2023).

Murray, R. et al. (2013) “Girth pressure measurements reveal high peak pressures that can be avoided using an alternative girth design that also results in increased limb protraction and flexion in the swing phase,” The Veterinary Journal, 198(1), pp. 92–97. Available at: https://doi.org/10.1016/j.tvjl.2013.07.028.