Rider Biomechanics Doesn't Change - Joint Angles Do

I recently shared a post comparing two skeletons sitting on a saddle. One skeleton was sitting with a balanced pelvis, while the other showed a pelvis positioned at a similar angle to the standing skeleton next to it. I simply asked which represented the correct and balanced sitting position for a rider.

The same pelvis position in standing and sitting (A) v a balanced pelvis and trunk (B)

The responses were interesting.

Quite a few people came back saying that a three-point seat with loading through the pubic arch was the correct answer. When I asked why, the only explanation I really received was something to do with the army. Which was ironic given the the point of the post was to highlight something I think is becoming increasingly important in the equestrian world - we should use anatomy, biomechanics, and physics to explain what happens in riding, rather than trying to make anatomy fit a theory. No one could give me a reason why they should have three points, and ignored all the facts I presented why it should be two (seat bones).

There are countless riding theories, methods, and explanations out there. Some are excellent. Some are based on observation and experience. Some have simply been repeated for so long that they've become accepted as fact. The problem is that when we actually look at the anatomy and mechanics of the human body, some of these ideas don't make a lot of sense.

As a rider physio, I've always believed we should start with the human body.

How does the skeleton balance?

How do the joints move?

How does force travel through the body?

How is movement controlled?

Once we understand those principles, we can then apply them to riding.

What surprised me even more than the comments about seat position, however, were the comments saying that the answer depended on the discipline or gait

Now, I can partly understand why people might say it depends on the gait. After all, we don't sit in one fixed pelvic position when we ride. The pelvis tilts forwards and backwards, moves side to side, and rotates as it follows the horse's movement. A rider's pelvis is constantly adapting. However, those movements occur around a balanced starting position. The unbalanced skeleton in my image wasn't simply showing movement. It was showing an anteriorly tilted pelvis where the rib cage and head position had also shifted to allow the rider to remain upright. In other words, the rider wasn't balanced because the body had already started compensating.

That's not a position we want to spend time in, regardless of gait, so whilst the person commenting was quick to make a point that we don't stay in the same pelvic position when riding (agree) they also failed to actually look at the skeletons.

The discipline argument, though, is one I struggle with.

A balanced rider is a balanced rider regardless of discipline. Whether you're riding dressage, showjumping, eventing, endurance, mounted games, western, or simply enjoying a hack, the principles of human balance do not change.

The skeleton remains the same. The muscles remain the same. The joints remain the same.

The nervous system responsible for controlling movement and balance remains the same.

What changes are the joint angles.

From a rider biomechanics perspective, a balanced dressage rider and a balanced showjumper should demonstrate the same fundamental principles. Both require control of their centre of mass. Both require stability through the trunk. Both require control of the pelvis. Both require the ability to absorb and adapt to the horse's movement. The difference isn't the balance.

The difference is how and why different movements are accessed. In dressage, the stirrup leathers are typically longer. This creates greater hip and knee extension. The leg hangs further underneath the rider, bringing the weight of the leg more in line with the weight of the trunk and supporting prolonged periods of sitting.

Same balanced rider as earlier but in a different saddle.

In jumping, the stirrups are shorter and the stirrup bars are generally positioned further forwards. This increases hip and knee flexion and allows access to a larger range of movement. It becomes easier to shift the centre of mass forwards when moving into a half-seat position and to accommodate the demands of jumping.

The requirements of the discipline change but the principles of balance do not. Balance is simply the ability to control your centre of mass over your base of support.

When sitting in the saddle, that base of support is primarily the pelvis. The rider's centre of mass doesn't suddenly change because they have swapped from a dressage saddle to a jumping saddle. The physics remain exactly the same.

This is one of the reasons I often find myself questioning discipline-specific explanations for rider position. Too often we start with a theory and then try to make anatomy fit around it.

I prefer to work the other way around.

Let's start with anatomy.

Let's start with biomechanics.

Let's start with physics.

Then let's see whether the theory still makes sense.

Over the years, working as a rider physio, I've realised that many riding problems aren't actually riding problems at all. They're human movement problems.

A rider who struggles to sit to the trot may lack pelvic control, who tips forwards may struggle to organise their centre of mass.

A rider who grips with their thighs may be searching for stability because they can't find it elsewhere.

A rider who struggles to maintain a position may have limitations in mobility, strength, stability, balance, coordination, or body awareness.

Yet very often these riders are simply told to sit deeper, sit up straighter, engage their core, or keep their leg still.

The instruction itself isn't necessarily wrong. What's missing is the explanation. And that's exactly why I created Riding Ready.

Over the years I've realised that many riders are trying incredibly hard to improve but don't fully understand how their body works in the saddle. They're often given positions to achieve without ever being taught the biomechanics behind them.

Once riders understand the "why", everything changes, they begin to understand why balance feels difficult, why certain positions feel natural while others don't. Why they struggle with particular movements and why some coaching instructions click instantly while others seem impossible.

Most importantly, they begin to understand how their own body influences what happens underneath them. And that is what Riding Ready is all about- improving the understanding, body awareness and physical ability of riders.

Starting on 1st July, we'll begin with one of the most important topics in rider biomechanics - how the saddle, pelvis, and trunk work together to create a balanced rider. Over eight weeks, we'll explore the anatomy, biomechanics, and science behind rider position and movement. We'll look at how balance is created, how movement is transferred between horse and rider, how the pelvis and trunk work together, and why mobility, stability, strength, coordination, and body awareness all play such important roles in riding performance. Each week includes articles, lessons, videos, and exercises designed to improve not only your understanding of rider biomechanics and rider balance, but also your ability to apply that knowledge to your riding.

If you haven't already signed up for the free Riding Ready Foundations Course, now is the perfect time. Launch offers will be released very soon, and the course begins on 1st July. If you've ever wanted to understand rider biomechanics, rider physio, rider balance, and the science behind effective riding, this course was created for you.

The new Riding Ready Academy will become the new monthly membership, replacing the current Rider Physio Video Subscription. It will bring together rider biomechanics education, rider physio, exercises, riding tutorials, rider problem-solving, courses, exclusive member content, and member discounts all in one place.

The aim isn't just to give riders exercises to follow. It's to help riders understand why they are doing them, how they relate to riding, and how the human body influences what happens in the saddle. By understanding the science behind rider position, balance, movement, and performance, riders can make better sense of coaching advice, identify their own limitations, and develop the skills needed to become more effective in the saddle.

Whether you're looking to improve your rider position, understand rider biomechanics, overcome physical limitations, solve specific riding problems, or simply learn more about how your body works when you ride, the Riding Ready Academy has been designed to provide the knowledge, guidance, and practical tools to help you achieve your goals.