How Horses Carry a Rider, and Why It's Important

Horses movement starts with energy being sent to the hind end, and the forward swing of a hind leg. (See posts about strides and engagement.) 

Horses use their entire body to balance, and travel forward in space. Their back acts as a suspension bridge from withers to sacrum, holding up the viscera (the internal organs in the main cavities of the body, especially those in the abdomen) and the ribcage. They use their neck as a ballast, but almost every muscle in their body is involved in locomotion (means of movement in space). 

The reality is, no horse can move exactly the same under a rider as they do while moving free. They have to account for the weight and balance of the rider. Riders are sitting directly on the chain of muscles that run along the horses top line, and therefore greatly influence the usage of these muscles. 

In order to move efficiently and safely under saddle, a horse must engage their abdominals, and therefor reach underneath their barrel with the hind legs, flexing their back, and balancing this out with a slightly lower and engaged head and neck. 

A young horse often starts out accounting for rider weight by hollowing out the back, flattening the croup and stunting the motion of the hind legs. This is where training can come in. Before learning anything else, the horse needs to learn how to carry a rider without causing damage to themselves. 

As riders, we sit directly over the horses spine, on top of their moving back muscles. Our legs wrap around the ribs and part of the lateral oblique as well as the serrratus ventralis muscles. This makes our balance, flexibility and overall fitness of upmost importance.

This is a reason (among many!) to make sure you have adequate saddle fit. If the saddle is putting undue pressure on any part of the spine, scapula or muscles surrounding them, the horse will automatically shy away from that pressure or pinch,  therefore changing their posture and movement to compensate. Eventually, this can change their behavior, willingness, and even overall muscular development. 

As horses change in fitness level, their back can change shape, making even a well fitting saddle into one that is no longer an ideal fit. This is why it's so important to understand how to check a horses back for pain. Below is an easy how to on how to check. This should be done often, while grooming either before or after working. Watch for both obvious signs of pain, as well as more subtle indicators

How to Check Your Horse's Back

Obvious:

• Sinking the back down, flattening the croup
• Pinned ears
• Shifting away from the pressure 
• Stomping or kicking

Subtle: 

• Tightening of the muzzle 
• Twitching of the skin (as if theres a fly) 
• Holding their breath 
• Widening of the eyes 
• Guarding of the muscles (tightening up as you apply pressure)