The Asynchrony Theory
The three-element asynchrony of horse, saddle and rider interaction
After carrying out a series of innovative scientific studies throughout 2010, The Saddle Research Trust has discovered
evidence that indicates measurable characteristics in saddle performance. This ground breaking new work has also
highlighted previously unrecognised areas of saddle performance. These findings, which have the potential to be of
great importance to the future of equine performance and welfare, urgently require further investigation.
Out of these studies, a new theory has been born: The three-element asynchrony of horse, saddle and rider interaction.
Rider Asymmetry
Initially, the object of the SRT studies was to measure the effect of rider asymmetry. However, it soon became apparent
that there was a more complex pattern of interaction than could be simply explained by a rider sitting crookedly.
Most people will be aware that their bodies are not perfectly symmetrical, and as riders, we are usually aware of being
right or left-handed. In most instances, this “handing” tends to favour the right; even if a person writes with their left
hand, their posture is generally right handed. This is commonly described by riding instructors as “collapsing the hip”.
More accurately, this is described as “hyperflexion of the spine”. The rider will favour sitting more to the left of the saddle
and in doing so, bend the waist to the right, and rotate the upper body to the right. (Fig. 1)
The effect of this is reduces coordination and balance, resulting in increased loading of the left stirrup and
corresponding gripping with the right leg.
Fig. 1 Collapsing the right hip
The De-Coupling Effect
In general terms, this means that the rider has a tendency to a vertical misalignment in the left/right plane: imagine a
puppet on a string – if the strings on one side are loose, he will extend his joints, while the tighter strings on the opposite
side will contract the joints – we describe this as decoupling.
Fig. 1b The decoupling effect
The decoupling effect describes the exaggerated loss of symmetry of the rider in the vertical plane.
The movement of the horse’s back and limbs moves the saddle; the more rigid the frame of the saddle, the more
movement will be generated. Our observation is that saddle movement is always asymmetrical. This generates an
unstable platform for the rider. This instability consequently creates imbalance in the rider; the resulting compensatory
action of the rider in turn accentuates asymmetrical posture.
In fig. 2, the three-element asynchrony is clearly demonstrated. The same horse and rider are viewed in two different
saddles. On the left, the rider can be seen in her own rigid saddle and on the right, in a flexible saddle.
Taken during the same stride phase, the left hand image shows that when the right hind is weight bearing, the horse’s
pelvis rolls to the left and the saddle drops to the right - the rider hyperflexes / decouples to the right. In the right hand
image, the synchrony shows a marked improvement with the use of a flexible saddle.
Fig. 2 The de-coupling effect: vertical misalignment
Horse Asymmetry
A similar lack of symmetry exists in the horse in the horizontal plane. Like humans, horses tend to be right handed. The
horse, by contracting the right side of his body, preferring to flex the neck and poll to the right, and therefore pushing
more weight onto the left forelimb, often demonstrates this. The horse’s movement is no longer smooth and along two
tracks. The horse “positions” itself to the right and moves the quarters crookedly. In trot, this can be observed as a
tendency to swing the quarters to the left, but in the canter, this is reversed with the quarters usually swinging to the
right.
In conventional treed saddles, horses will tend to move the tree points alternately as the scapula moves back and forth
against them. Any asymmetry either in scapula movement or shape will create greater asymmetrical movement of the
saddle. Similarly, if the saddle is asymmetrical, it may create greater lateral excursions on one side of the horse’s back
in comparison to the other.
Fig. 3 the scapula swings against the tree points
This effect can be observed from the rear - the cantle swings from side to side as the horse moves along a straight line.
In the example below, a wide shouldered native pony constantly pushes the saddle from right to left as he moves,
creating an unstable platform for the rider.
Figs. 4a & 4b Saddle movement creates an unstable platform for the rider
This effect can be exaggerated when the horse turns. The inner scapula will become more dominant in pushing against
the tree point. Without the rider, the saddle may be even less stable at the rear with the sunbsequent swing even
greater (Fig. 5). The weight of the rider will not stop the swing, but will serve to increase the torque against the horse’s
back.
Fig. 5 The dominant scapula pushes against the tree point in the turn.
In the fig.6, the saddle has swung to the extreme right, positioning the left side of the base panel onto the extreme right
side of the horse’s back.
Fig. 6 Extreme movement of the saddle
In the past, riders have often been criticised for poor technique, and at times it may be true, but is far from the whole
story, which is far more complex. In our studies it does not appear to be a simple “chicken and egg” that is “Which
became crooked first - the rider or the horse?” It is better described as the “derailing effect”.
The De-Railing Effect
Imagine railway carriages running along on a track – if there is an obstruction that stops any part of the carriage from
flowing freely along the track, it will derail.
Fig. 6b The derailing effect
The derailing effect describes the loss of symmetry of the horse in the horizontal plane. This means in general terms
that the horse has a tendency to horizontal or longitudinal misalignment. If the force generated by the hindlimbs is
impeded, it will tend to push the vertebral column and limbs off track in a similar way to a train crash causing the
carriages to derail and jacknife.
The horse compensates for carrying the asymmetrical rider and the subsequent loss of balance by counterbalancing
with the neck and bracing the load onto the left forelimb. The hindlimbs are in turn prevented from swinging freely in a
forward motion, no longer being able to travel in the same path as the blocked forehand therefore deviating to the side.
The tendency is that the asymmetrical rider exagerrates the asymmmetry of the horse and vice versa.
Our understanding is that the degree to which this exaggeration occurs is greatly affected by saddle design and fit. A
saddle that can accommodate the correct movement of the horse without excessive movement or force will enable the
horse and rider to be more symmetrical and balanced. The saddle can create a viscious circle or possibly a benign one.
A horse’s shape and movement can tilt the saddle either to the left or to the right whether it is static or in motion. The
horse’s back shape is often asymmetrical, so even at halt, the saddle may settle crookedly on the horse’s back. Equally,
the saddle may appear to sit symmetrically at halt, but moves asymmetrically when the horse moves. The pattern of this
movement will also alter between different riders using the same saddle on the same horse.
Fig. 7 An asymmetrical back
If there are any clinical reasons why the horse may favour one side of its body more than another, it may contract the
musculature on one side and move in an unlevel fashion, even if not overtly lame, causing the saddle to be carried
asymmetrically. So-called “bridle lameness” is often a ridden performance issue that cannot be simply explained, but
may be a complex cocktail of symptoms involving subtle asymmetries in the horse and its movement, the rider, the
saddle and most importantly, the interaction between them.
In the example below, the saddle can be seen tilting to the left at halt, thus leaving the rider’s left seatbone unsupported
and causing her pelvis to drop to the left.
Fig. 8 The saddle tilts to the left at halt
The same combination, in sitting trot, generates a more complex pattern. When the left hindlimb is weight bearing, the
horse’s pelvis rolls to the right and the saddle moves and tilts to the left, taking the rider’s pelvis with it. When the right
hind is weight bearing, the saddle and rider are aligned. This is an asymmetrical pattern, demonstrating a clear lack of
synchronisation in the three-way interaction of horse, saddle and rider.
Fig.9a Left hind weight bearing
Fig. 9b Right hind weight bearing
In most research studies, if a single question is asked, the answer is often a myriad more questions.
We have raised such questions as: “What effect does this three-way asynchrony in the interaction of horse, saddle and
rider have on the welfare and performance, not just of the horse, but also of the rider?” Furthermore “ Do different
saddle designs affect the synchrony in different ways?” This valuable work may be in its infancy, but will have farreaching effects. The fast pace of technological development means that we are now able to utilise systems that can
analyse performance parameters and investigate the effect of concepts that can make a real impact at all levels of
equestrianism, from amateur to elite.
The Saddle Research Trust is continuing its work in investigating welfare and performance in the horse and rider and
will publish the results of current studies as they become available.
To find out more about the SRT, to support its work or to become involved in research projects, please visit: www.saddleresearchtrust.com or email [email protected]