A brand-new peer-reviewed paper has just been published in Animals by Animalweb experts Dr David Marlin and Dr Roberta Blake, alongside co-authors Olivia Randell and Emma Mayhew.
Why study girths?
The girth – may look simple, but it plays a direct role in how pressure is distributed across the horse’s back. Riders and saddle fitters often debate girth type and tightness, but until now there has been very little published research on how these variables affect biomechanics and comfort in ridden horses.
The FEI Equine Ethics and Wellbeing Commission has highlighted tack as an area needing more research, and this paper is one of the first to look specifically at girth design and girth tension under ridden conditions.
What the team did
Six horses in regular work were ridden at rising trot under four conditions:
- Two girth designs: a standard straight girth and an anatomical (shaped) leather girth
- Two girth tensions: 8 kg (looser) and 16 kg (tighter)
Each horse went through all four conditions in a semi-randomised order. To ensure robust results, the team used:
- A Tekscan pressure mat under the saddle, recording 100 times per second, to map pressure distribution across the horse’s back.
- Reflective markers on the forelimbs and high-speed video (240 frames/second) to measure stride length, joint angles, and limb flexion.
- An in-line load cell gauge to precisely set the girth tension at 8 or 16 kg before each trial.
All horses used their own saddles (checked for fit) and familiar riders to keep conditions realistic and consistent.
What they found
- Limb movement: There were no major changes in stride length or joint motion between girth types or tensions, except for a small difference in carpal flexion when the anatomical girth was used at 8 kg tension.
- Saddle pressure: Tightening the girth from 8 kg to 16 kg did not increase the overall average pressure, but it shifted the pressure forward (cranially) towards the front of the saddle.
- Implications: Over time, this forward pressure shift could contribute to discomfort, reduced freedom of movement, or even thoracic back pain.
The study
The research explored how different girth types and levels of tightness affect horses when ridden. Specifically, the team compared a straight girth and an anatomical girth, each fitted at two different tensions (8 kg and 16 kg), in six horses ridden at rising trot.
Using high-tech pressure mats and slow-motion video, they analysed:
- Pressure beneath the saddle
- Forelimb stride kinematics
Key findings
- Changing girth type (straight vs anatomical) made little difference to how horses’ limbs moved.
- Increasing girth tightness, however, caused a clear shift in saddle pressure towards the front of the horse’s back.
- While immediate stride patterns didn’t change much, this pressure shift could have long-term implications for comfort, back health, and performance.
Why it matters
Girths are a vital but sometimes overlooked part of tack. Tightening them may seem simple, but this study shows that even moderate changes in tension can alter how saddle pressure is distributed. Over time, this could contribute to discomfort or injury, making girth fitting and adjustment another important factor in horse welfare.
This is one of the few studies to examine girth design and tension under real ridden conditions, providing valuable insights for riders, saddle fitters, trainers, and vets alike.
Read the full open-access paper here: The Effect of Girth Design and Girth Tension on Saddle-Horse Pressures and Forelimb Stride Kinematics in Rising Trot (Animals, 2025)
