📏 Vet Guide: Saddle Fit and Tree Width’s Effect on Your Horse’s Spine | 2025 Thoracolumbar Health & Performance Insights 🐴

By Dr Duncan Houston, BVSc

A properly fitted saddle is essential to a horse’s comfort, soundness, and performance. Yet, a persistent myth in the equine world suggests that using a **wider saddle tree** can actually improve back function. The theory? More room equals more movement. But science is finally weighing in—and the results may surprise you. 🧠🐎

In this 2025 guide, I’ll break down the latest research on **saddle tree width** and its impact on **the horse’s thoracolumbar spine**—that critical region from the withers to the pelvis. 📊🩺

🧠 Understanding the Thoracolumbar Region

The **thoracolumbar spine (T-L region)** runs from the withers to the pelvis and forms the foundation beneath your saddle. This area must flex, extend, rotate, and bend laterally to support your horse’s movement in all disciplines—from dressage to jumping to trail riding. 💪📐

A poorly fitted saddle—too narrow or too wide—can **restrict movement**, **cause discomfort**, and even lead to long-term spinal issues or behavioral problems. ⚠️

🔬 The Study: How Tree Width Affects Spinal Motion

Dr. Russell Mackechnie-Guire and a team of researchers set out to test how **tree width affects spinal motion** using validated technology. The study involved: 📋

• 🐴 13 sound horses with no back pathology
• 🧠 Inertial measuring units placed at the poll, withers, mid-back, lower back, and hips
• 🪶 Two similarly sized riders
• 🪑 A general-purpose adjustable English saddle (Kent & Masters)

Each horse was ridden with **three saddle fits**: ✅ Correct fit, ❌ Narrow (10% smaller), and ❌ Wide (10% wider). Master-qualified saddle fitters ensured precision. All horses were cantered on both reins on a calibrated track. 🧪

📉 Key Results: Wider Is Not Always Better

1. 🧍 Less Flexion & Extension with Wide Trees

• Horses in wide saddles had **reduced movement at the mid-back** (T-L region)
• This reduced spinal motion could **limit performance and increase strain** over time

2. 🔄 Altered Axial Rotation

• Wide saddles increased axial rotation at the withers
• But decreased it at the mid-back and lower back—affecting biomechanical flow

3. ↩️ Narrow Trees Reduced Lateral Bending

• Narrow saddles decreased the horse’s ability to bend sideways at the mid-back
• This could limit flexibility and lateral responsiveness

The conclusion? **Both wide and narrow saddles negatively altered spinal motion** compared to a properly fitted tree. 📉

⚖️ The Myth: Is Wider Really Better?

In some riding circles, it’s been claimed that a wide saddle allows “freedom of motion.” But this study contradicts that idea—showing that **too wide a saddle can actually compress tissues**, **destabilize the rider**, and reduce efficiency of movement. 🧠

Like shoes or helmets, saddles must be **fit to the individual—not based on myths or generalities**. 🎯

📋 How to Ensure Proper Saddle Fit in 2025

Steps to Follow:

• 🧑‍🔬 Work with a **qualified saddle fitter** familiar with equine biomechanics
• 📏 Evaluate tree width, gullet clearance, panel contact, and symmetry
• 🎥 Film or track performance before and after saddle adjustments
• 📊 Use technology like pressure mats or inertial sensors when available

Your horse’s feedback is key. Watch for signs of discomfort like tail swishing, stiffness, short stride, or poor performance. ⚠️

📲 Use Ask A Vet to Support Saddle Fit & Spinal Health

The Ask A Vet app helps you manage saddle fit questions, identify back pain, and protect long-term soundness:

• 📸 Upload photos or videos of saddle fit and back movement
• 📋 Ask about soreness or behavior changes under saddle
• 📊 Get insights from equine vets on spinal support and muscle development
• ⚖️ Learn how to select saddles based on your horse’s build and workload

Saddle fit is not optional—it’s performance medicine. 🐴📲

✅ Saddle Tree Width Takeaways for 2025

• 📏 Tree width directly impacts back movement and rider alignment
• 📉 Wide trees reduce mid-back flexion and axial rotation
• ↩️ Narrow trees reduce lateral bending at the mid-back
• 🧠 Correct fit maximizes comfort, symmetry, and spinal mobility
• 📱 Use Ask A Vet to assess back issues and support saddle fit decisions

📲 Final Thoughts from Dr Duncan Houston

Your horse’s back is not a flat surface—it’s a complex, dynamic structure. A properly fitted saddle is **a non-negotiable part of your horse’s wellness and longevity**. Forget the myth that “wider is better.” Science shows that **precision fit wins every time**. 🧠💙

Download the Ask A Vet app to assess spinal motion, evaluate saddle fit concerns, and build a back care strategy that keeps your horse healthy and performing at its best. 🐎📱