Rider Kinematics and Equine Locomotion

How does the movement and forces of the rider influence equine movement and how much does it matter? A summary of work presented at the IAVRPT by Dr. Russell Mackechnie-Guire

An important question to ask: Is some rider asymmetry normal and when does it affect performance?

 

So - when we are riding we all try to be symmetrical right?  We think about how long our stirrups are, we try to notice if we are leaning forward, backwards or sideways, and we try to keep our hands still and our weight equal as best we can. 

But.. we’re actually on our horses for a relatively short time. 

How much time do riders actually spend thinking about making themselves symmetrical when not on the horse?

Answer = not that much! And we spend more time off the horse than on. 

We need to consider that rider kinematics are hugely influential over horse biomechanics and by doing some specific exercises in our general lives we will be influencing our horse positively when we ride them. 

 

Kinematics

Let’s define Kinematics - this is the mechanics connected with the motion of objects

So in a rider context - how the rider is moving on the horse's back

If you think about it, subtle movements of a rider can influence whether a horse turns, left, right, halt, or go.  

The fact is - humans are not symmetrical creatures.  So we have some work to do on ourselves if we are expecting our horses to work equally and to be balanced and comfortable in their work. 

 

Rider Asymmetry

Research has shown that 90% of people are right handed, 80% are right legged, 70% are right eyed, and 60% are right eared (Hepper 2013).

Interestingly the preferred limb is not necessarily the stronger limb and the more dextrous limb may be used for performing skilled tasks. 

These asymmetries that are seemingly innate within our development have actually been identified as far back in our growth as the first trimester of pregnancy when the tiny foetus is developing - this is long before cortical connections (links via nerve fibers) to the limbs have even been developed!

 

Horse asymmetry

To throw a spanner in the works, horses generally have a left-sided preference in research.

This has been examined through a left ear, left eye and left foot preference response.

 

Rider Asymmetry

Russel Mackechnie-Guire, director of Centaur Biomechanics, has shown us through his research using pressure pads on the saddle, that many riders do not put equal pressure through their seat bones, often having more pressure through the left or the right hand side consistently. 

Riders often drop a stirrup down a hole or hitch one up if they’re feeling unlevel, however, Duval et al, 2010, managed to show that the symmetry of the pelvis and upper body is highly dependent on foot position. 

Makes sense when you think about it.  Unless you have a medical discrepancy on leg length, the only thing that unlevel stirrups are going to do to you are essentially tip you one way or the other - however subtle this is and however much you notice as a rider. 

As you would expect - the research showed that if the right stirrup was shortened, the right side of the pelvis would raise higher than the left and the right shoulder would tip downward to compensate. 

 

Picture

Forces on the horses back

During walk the weight of the rider is pretty consistent.  So for example, if a rider weighs 70kg this is the weight that the horse will be experiencing.

BUT.. move up into trot and this doubles!  So the horse is experiencing 2 x 70kg.. 140gk (pretty fast way to gain weight!)

Then move up into canter and you can add another half of the rider's original weight on.

140kg + 35kg = 175kg (this is what our horses are experiencing). 

(Frueworth et al)

 

Have you ever given anyone a piggy back and tried to run - it gets a lot heavier and we pretty quickly come back to walk.

So we can see from this that if our horses are undergoing these weight increases then any rider asymmetry is going to be far more influential over horse biomechanics than we thought. 

 

Horse biomechanics

The horse actually moves asymmetrically - they lift one leg, then they lift the next, and a rider will show the horse's movement throughout their own body - i.e.we don’t sit perfectly still on a moving object.

However, the ability of the rider is crucial to counteract or absorb these asymmetrical movements (Mackechnie-Guire 2022 IAVRPT conf.). 

 

Horse biomechanics and locomotion

Every stride the horse takes will experience pressure from an asymmetric rider.

Horses will increase movement in their backs when more rider asymmetry is shown. 

 

Factors influencing rider symmetry

Saddle Fit

Saddle fit is essential to optimising horse-saddle-rider interaction

The saddle is vital when we’re looking at ridder symmetry.  An incorrectly fitting saddle can cause a rider to tip forward or backward, sit more to one side, and can even alter leg position dramatically.   

‘Saddle roll’  can be created when a saddle isn’t fitting correctly.  This can affect rider position and the way the weight and position of the rider then interact with the horse

The horse is the primary cause of saddle fit issues and saddles tipping or slipping are often indicative of horse asymmetry that may need investigation. 

 

Rider Position

The position of the rider plays a significant role in equine performance and communication of the rider with the horse can be altered by injury or rider dysfunction. 

 

But what can we do to help our horses?

Firstly we need to consider that some asymmetry may be normal and actually not affect us or our horses adversely.  This hasn’t been fully researched, however, there will be a point when the amount of rider asymmetry becomes too much and influences our horses negatively. 

It’s important that a rider realises where a ‘neutral’ pelvis and back is which could take some unridden work to discover. 

So, to help us to gain more symmetry in our own bodies - what can we do?

 

Exercises to help rider asymmetry

  • Equine pilates - this branch of pilates is specifically aimed at riders and will create balance and core strength

 

  • Yoga ball - sitting on a yoga ball engages our core muscles and forces us to sit equally. Consider swapping your office chair for a yoga ball and get your core engaging throughout the day.  Or devote 10mins to a yoga ball in the evenings.  Tip from side to side and backward and forward to discover where your neutral pelvis and back are and what that feels like. 

 

  • Stand on one leg - sounds bonkers but balancing on one leg helps strengthen your core and find your balance. To step it up, shut your eyes for a few seconds - notice how it’s a real game changer for keeping your balance.  Top athletes will jump up and down, side to side and over hurdles all with their eyes closed. 

 

  • When riding, spend the first 10 mins walking with no stirrups. Many of us will have done endless no stirrup work as kids and stopped as an adult.  This is really vital to our symmetry as a rider.  Spend time lifting your hip up and away from the saddle and finding a neutral position where weight is equal before putting your feet back into equal stirrups.

 

  • Make sure your stirrups are level. Regularly take your stirrup leathers and compare their lengths.  Stirrup leathers can stretch and it’s a good idea to swap them from left to right to maintain equal length.  Make sure you put each side on a corresponding hole for length, not just the number marked on the leather. 

 

Exercises to help horse asymmetry

  • Get those raised poles out. Plenty of in hand-raised poles will help our horse engage equally without the influence of a rider, meaning when you mount up they will have more chance of being symmetrical.

 

  • Long and low work - allow your horse to work long and low for at least 10mins before collecting them into an outline. This will allow muscles to relax, correct engagement of core muscles, and avoid tension from being asked to go in an outline too early in a work session. 

 

  • Carrot stretches help your horse stretch muscles on either side of his body equally giving him a better chance at symmetry.

 

  • Saddle fit - not an exercise but an absolute essential that your saddle is level and fits both the horse and rider.

 

  • Physical check - get your horse checked regularly by a physical practitioner. A professional will be able to spot asymmetry and help to correct it. 

 

Physical Therapists for Horses

It’s important to have a regular check for your horse to help maintain and boost symmetry. 

A physical therapist needs to look at the whole picture - this is going to include the horse, rider, saddle, and more.  It’s really important to consider every aspect when looking at horse biomechanics and the influences affecting it.   

 

References

Hepper 2013 - Symmetry in Human Development

Frueworth et al 2020 - Influence of Rider Weight on Movement of Horses During Walk, Trot and Canter.

Mackenchine-Guire et al 2018 - Relationship Between Saddle and Rider Kinematics, Horse Locomotion, and Thoracolumbar Pressures in Sound Horses