So today we answer the question “why do the
Whitakers, Nick Skelton etc. ride with their elbows sticking out?”
I say we. I mean me, but you know join in
any time.*
I’m slightly fascinated with the “Whitaker
elbow.” In the 90s we all did it and as I just wrote up some old notes (see 12 things I learnt on my first Tom Whitaker lesson) it sprung back to
mind again. Conventional riding position has your elbow fairly flat to your sides, giving you a fuller range of arm length and more effective shock absorption.
It allows your hands to follow the horse’s mouth, giving a soft contact. Yet in
show jumping, particularly in old school riders, an outward elbow is common –
think John Whitaker – or any Whitaker – Nick Skelton, Tim Stockdale etc. I’ll let you do the Google work.
So what’s the advantage?
First let’s recap the conventional position
and hopefully head off any angry commentators.
Conventional
position:
If like me you have a short arm this gives
you extra reach for the horse to lengthen his neck. It also gives you more degrees
of freedom (elbow, shoulder and wrist), and better motor control, so you’re
more able to move your hand as necessary to keep rein tension constant (follow
the horse’s mouth). It’s genius, it works and I’m not here to argue against it.
Same scale with arm (glenohumeroid) more flexed and elbow
more extended, and look how far the hand has moved. Brilliant.
Elbows Out
What happens if we turn our elbows out? To
imitate this posture we’re both abducting the arm (moving it away from the
body) and rotating it so that the elbow swings forward. What happens then is the
shoulder and back muscles are stretched, opening the rib cage (pectoralis) and pulling
on your spine (rhomboid major). This also activates your core muscles (which include
spine stabilisers, diaphragm and the abdominals) to stabilise the spine and rib
cage.
Graph
for people that like graphs. Confusingly here negative adductions (to the left) mean movement
away from the body, which increases pull on pectoralis major.
Elbows
out is often used in “power poses” which are meant to give a confidence boost or psychological
lift and I suspect this is partly as a back widening effect, and also partly
as opening the ribs improves breathing, which in turn calms the physiological (fear)
response. I’m speculating here.
Sadly for any type of riding, soft hands are basically
everything and this posture definitely puts your soft hands at a disadvantage so this isn’t a recommendation.
Try now just moving your hands forward and back towards an imaginary horse’s
mouth in the elbows-out and elbows-in positions and feel the resistance that turning your elbows out causes. However personally I often adopt a “sit tall, elbows
out” posture for at least the first fence or two if I’m feeling nervous when I’m jumping,
and for me and my horses it helps. At my (low) level of refinement the thing that helps my hands the most is a stable core with relaxed arms so if turning my elbows out a little even just reminds me to do that then there’s another trick that I have.
Disclaimer
*
This is a real quick and dirty “I should be cooking dinner”
set of calculations based mostly on the musculo-skeletal modeller’s
perspective of the effects of turning out the elbows, not anyone’s actual reasons. Happy to hear more applied or considered thoughts. Also I’m not
really allowing for the full 3D aspects here and if there’s one
cardinal biomechanics rule it’s always be very, very careful if you’re not in
full 3D. It’s easy to measure and analyse things in 2D. Easy, and almost always
wrong. In this case I have looked in 3D but only in a static sense. Similarly in places I say shoulder joint, when I mean one or all of the four girdle joints, and so on, because let’s not get carried away here and hide behind confusing terminology in place of accuracy. If there’s
interest in this beyond my dinner-time musings I can always actually run some movement
data and model it properly!
I have a teenager. He’s fairly sweet and not normally given to tough love. Here’s what he had to say about my most recent riding injury:
Me: It’s just unfair. I tucked, I rolled, I got out the way of the horse. I did what I was meant to do.
Teenager: And you broke your shoulder not your back. That’s exactly what’s meant to happen. Now you get over it.
Voila, the effect of being parented by a biomechanist who consults in forensics. My son instinctively understands a fail-safe. From an engineering perspective a fail-safe is a way of preventing a more serious failure. It is a safety net – it doesn’t stop you from falling, but it does prevent the full impact of hitting the floor. It’s inconvenient when your house plunges into darkness because of a trip switch or a fuse that’s blown, but on the plus side
your house did not burn down and you are not on fire. In the horse’s legs the accessory (check) ligaments of the flexor tendons are partly a fail safe. When they break it is a large problem and they take a while to heal but nothing like the carnage that would have occurred if the check ligament had not “taken the strain” literally and figuratively and the main tendon had been allowed to tear.
In the British horse industry in particular, we love a fail safe. We tie our horses up with a breakable link, designed to snap under tension, a practise often frowned upon in the U.S.A. I see the arguments on both sides but I will say this: I once cross-tied a horse with both a leadrope tied solid and a travel bungee. When the horse slipped the travel bungee did exactly what it was meant to do and snapped, the leadrope did not and it flipped the horse over. The physical and psychological damage was pretty dramatic, and even the pure financial cost was a lot more than a replacement bungee. Anecdotal evidence counts for little other than to illustrate that whilst there are few times when you want an unexpectedly loose horse, there are some.
I’ve seen a lot of people complain when their kit broke, and I myself have lamented my damaged hat, ripped rug, snapped headcollar, etc. Working in equine biomechanics as an expert witness though, I’ve seen a lot of what happens when there is no fail safe. Personally, I’ve broken my ankle against a stirrup, so last year when I merely broke my stirrup I was happy enough to pay out to replace it. Similarly when a rug rips or the catch breaks, it’s always frustrating, but I’ve seen the alternative and that’s really not pretty. We use leather headcollars not just because they look the business but because – in the case of no acceptable alternative – they snap. Your stirrups may now be safety stirrups and your stirrup bars have long been designed to release the leathers. It’s worth extending that logic to every part of your horse’s world – your tack, your haynets, your ring-feeders, your fencing – if this fails, does it fail safely? If not, sometimes it can be quick and simple to change that. A fail safe is often cheaper than what it can save you from having to replace.
One of the most successful developments in this area is the safety cup (showjumping) or frangible pin (eventers). Gone are the days when even in showjumping if you came downwards onto a pole, such as a horse hitting the back bar of a spread, the only way that pole was going to shift was if you broke it in two (as often we did). Now cups are designed to release whichever direction you hit them in and I would encourage anyone to ensure that this is the type of cup they use in their competitions and at home. This release means that the cup also “fails” by hitting the ground and needs to be reset along with the pole, but as riders we already endure greater hardships than this. Horses do not need to hit their legs hard to learn to be careful, and jumping should be about the confidence to make mistakes, not a high-risk sport. The rotational fall is our greatest cause of serious injury and could yet be eradicated – the horse should never strike a solid enough object to be thrown into a cartwheel.
If release is not an option, our second defence for injury prevention is to dissipate the incoming force. Crumple zones in cars make modern vehicles rather easy to dent, but by folding up in a predetermined way the car protects the central passenger section from the worst of the blow. Someone else explains that here.
Your helmet is designed along the same lines to protect your head by self-destructing to absorb the blow. It’s got a pretty case around the outside so sometimes you can’t see the damage but still if you bash it you need to replace it. Body protectors on the other hand work by being hard, and saving your body from minor injuries and fractured ribs. They are not a fail safe. They won’t actually protect your spine or prevent internal soft tissue or crush injuries, that’s not what they’re designed to do (e.g. Mills and Gilchrist, 1990; Kelly et al., 2004). The utterly misleading misnomer “back protectors” and their compulsory use in some equestrian disciplines has rather dented any development or acceptance of the spinal protectors seen in other sports. There are plenty of people who tell stories where “without my back protector I would have had a spinal injury” but at the moment the evidence doesn’t support that. Various companies are trying to improve safety and create body protectors that can protect your spine. There is evidence for the need for better safety gear – particularly supports for the cervical spine – and only greater public awareness will help get these products developed.
I jump in a helmet/hat which is lightweight, flexible, vented and peaked. Those elements make it comfortable and beautiful, but give the manufacturers a nightmare job in making it sufficiently safe. My hat adheres to current safety standards, none of which address protection from rotational (brain-tearing) injuries, and those are the cases that would break your heart. These companies are the people we trust with our lives, yet bombard with our mostly fashion-based demands. We undermine them not just with our need for practical wearability, but with social media posts “exposing” hats which break into pieces – as many of the most safe are designed to do, in order to deflect the impact and save our heads. I wish every manufacturer every luck with their task.
Sox: externally rotated hinds, otherwise conformation just right.
An endo skeleton is a skeleton
that is worn on the inside. Some creatures, like beetles, have exo-skeletons
armour-plating their outside, horses have endo-skeletons providing support and structure from within, framed around a backbone, which makes them vertebrates.
Vertebrate bones are incredible piece of engineering.
Designed to withstand forces from all directions whilst still being as light as
possible. To do this, large parts of the bones have a honeycombed trabecular structure which has
been much copied in man-made materials. Trabecular or cancellous bone is basically composed of a series of small beams, so there’s material
where it’s needed, in the form of little supportive struts, and none where it
isn’t needed, cutting down on any extra weight. The property that’s really,
crazy, blow-your-mind clever, that we struggle to replicate in man-made
materials is its ability to adapt. The much-quoted Wolff’s Law tells us that
bone will adapt to the loads placed on it. That means that as long as you and
your horse are alive your bones are constantly adding struts, thickening parts,
and removing (reabsorbing) other parts. The whole system is constantly under
reassessment.
Why do we need to care about this particular marvel of
anatomical science? It means a number of
things for your horse. It means that:
a) Bones remodel to the strength we tell them that they
need. This means that they need an advance heads-up. If you’re going to do
something high impact, or have suddenly increased impact following box rest
then BUILD UP. By using repeated loading
within the horse’s current capabilities you can increase bone mass and strength
and hence stretch what is safe for him.
b) Bones are strongest in compression, since that’s the
direction they’re designed to load in. If they’re suddenly, unexpectedly loaded
in a different direction, for example by a bending force, they can often just
snap.
c) Bones will do their best to remodel if not correctly
aligned due to conformational defects, but usually this will mean bypassing the
bone and putting the extra strain on the joint.
Joints allow the skeleton to move. They’re essential, they’re magical, they
create the part of biomechanics that most people are the most excited about,
and yet they are a terrible weak point in the system. The majority of
orthopaedic problems originate at the joints. When we talk conformational
defects we’re normally talking about joints. The bones are just the linkages
that make the joints easier to see. The bones may be too long or too short, or
headed off in the wrong direction, but that deviation originates and inserts at
a joint, where the price is paid.
The joints are held together by collateral ligaments and
joint capsules and usually move due to articulating surfaces. This means that
it’s the collateral ligaments, articular surfaces and joint capsules that often
fail, along with the tendons responsible for taking the strain when movement
occurs.
Whether the horse is still or moving, it has to cope with
forces. If a horse stands on the ground, it is pushing down into the ground
with its body weight. Have a horse stand on your foot, it hurts. Horses rarely
stand on your hand. You can get kicked on the hand, sure, but then your hand
moves out of the way unless the floor supports it. I’ve yet to see someone
exert enough force with their hand to hold the horse up. At the same time as the horse is squishing
the ground, the ground is pushing back on it with an equal and opposite force.
Sometimes it doesn’t and the horse just sinks into the ground, but usually,
eventually, the ground pushes back hard enough that the horse can stand on the
ground.
We can measure this reaction force, the most confusing of
Newton’s forces, using a force-plate mounted into the ground. This can tell you
how much weight a horse is putting through an individual leg, by telling you
how hard the plate is having to push back, and what direction it’s pushing in.
In an ideal world we’d have one in every yard and vet clinic, telling us about
the subtle changes in the way the horse feels and functions. Biomechanics is
all about reactions to forces, and these are some of the very
forces we’re interested in.
Align these forces correctly with the bones, so they pass
straight through the joints, and the skeleton functions at its most efficient.
If a joint is not well-aligned, it will experience extra strain, and
potentially disease and failure.
Conformation
Whether
you’re choosing a new horse or trying to make the most of the one you’ve got,
being able to judge conformation is a handy skill. No horse is perfect but if
you’re aware of your horse’s weak points there’s a lot you can do to mitigate
defects, maximise soundness and make sure he’s up to the job. Many aspects of
conformation vary with breed and so some breeds may be more suited to one
activity than another, as different equine sports have different requirements.
However there are also a few basic conformation flaws worth watching out for in
all ridden horses.
As we’ve previously covered the
horse’s skeleton is actually very similar to our own. In the horse instead of
wrist we say knee, and instead of heel we say hock, but most of the bones and
tissues are the same. The horse is adapted to be as light and fast-moving as possible,
so he runs on his third fingernail/toenail, not the flat of his foot, and has
lost all “unnecessary” bones, including all of the other fingers and
toes. These adaptations leave a lot of bouncy joints for shock absorption, and
a lot of scope for variation.
Distal (lower parts of) legs
To assess limb conformation
you need a horse to stand well, and view him from the side, front and
back. Basically you’re looking for a
straight, well-balanced leg, with no major twisting in any direction.
Examples from the MUST HAVE book “Equine Locomotion” (Holmstrom Chpt, Back & Clayton Eds).
Pastern length is one of the
first aspects to check in the fore and hindlimb. If the pastern is too long the
fetlock will flex more, leading to excessive strain in the tendons or their
insertion points (such as the navicular or coffin bone). If the pastern bones
are too short or “upright” there won’t be enough flexion at the
fetlock for effective shock absorption. This means that if your horse has
pasterns that are unusually short or long, then you should minimise high impact
activities such as trotting on roads or a lot of jumping.
Straightness in the forelimb
In the front leg, a horsethat is over at the knee has the
appearance of a permanent knee bend, and this is not really that serious. A
horse that isback at the knee looks
like the knee has bent the wrong way. This causes additional strain on the
tendons and ligaments that struggle to maintain posture and support the weight
of the horse, particularly in jumpers or
racehorses. For these horses it’s a good idea to focus on tendon strengthening
exercises such as hill work (see previous posts).
Hobo: straightness from the front, check. Ability to wear a rug, lacking.
Pigeon toed (turned-in toes)
and toed-out horses are common. Toed-out hindlimbs are present in 80% of
warmbloods, so can be considered normal, and can even help with half-pass and
shoulder in. Toes that don’t point straight ahead are still not ideal due to
the increased stress to the lower parts of the limb, but not serious. Horses
with toe-in or toe-out are often seen competing at higher levels and it’s not
strongly associated with break down, although more extreme examples may cause
problems. Base narrow, toe-out forelimb conformation can increase interference
(brushing) injuries including splints so is often avoided in dressage horses.
For all other activities the addition of brushing boots can go a long way to
minimising this problem!
Toe-in conformation is often
seen with bench (offset) knees, which although common may predispose the horse
to splints and fetlock problems. These horses need to avoid deep surfaces where
possible.
Toed-out hindlimbs are not
the same as a cow hocks (narrower at the hocks). Horses who are only toed-out
and not narrow at the hocks will present a vertically straight hindleg if you
stand behind the point of the hock (and not behind the horse). Look at where
the hoof is pointed, forgive the deviation and stand behind the heel and hock,
then decide if the legs bend in at the hocks or merely point the wrong way. Sickle
hocks are over-bent when the standing horse is viewed from the side. They do
allow a horse to step under himself, but prevent him from being able to carry
that weight effectively and so are rarely seen in elite dressage horses. Poor
hocks, especially sickle hocks and cow hocks, have been associated with
osteoarthritis, bone spavin and back problems, so in these cases it is worth
avoiding occasions that cause a lot of strain – such as a lot of jumping, or
very deep or hard surfaces. Whilst horses with poor hocks might not have the
longest hunting careers, they rarely cause a problem in racehorses.
Hobo has straight but externally rotated hindlimb. Not cow-hocked, but looks similar from this angle.
On the other hand, in the
forelimbs knock-kneed conformation may even be protective and has reduced the
incidence of carpal fractures in racehorses.
Remus as a slightly knock-kneed
youngster (with poor hoof trim).
Straightness in the hindimb
As we reach the hoof, the
research shows that as the heels become more ‘underrun’ (low heels and long toes), the odds increase of
joint problems further up the leg. It is interesting that there is little
evidence that hoof angles affect the likelihood of disease or injury, only
evidence for the effect of hoof balance (differences between front and back).
Head, neck, body, upper legs.
Many aspects of conformation
that relate to the head, neck and body are difficult to measure objectively,
and so can lack scientific evidence, but breed differences in this area show
the effect of selective breeding for different activities. Plough horses and
racehorses look very different for a reason!
There is currently no solid
evidence linking shoulder conformation to injury, only performance. Elite
showjumpers and dressage horses have been shown to have more sloping shoulders
than average, and sloping shoulders correlate well with gait scores in young
horse performance testing.
It is worth remembering when
assessing the slope of the shoulder or croup that in some horses the outward,
muscular appearance does a good job of mirroring and representing the
underlying skeleton, but in many horses it doesn’t. It can be helpful to place
a piece of tape on the upper and lower parts of the shoulder bone to allow you
to stand back and observe the actual line. However a seemingly long and sloping
shoulder with good withers will place the rider in a good position in better
balance with the horse, and so the appearance of the shoulder can be as
important as its real slope.
Judges often use terms such
as “freedom of the shoulders” but high-speed analysis shows that
differences in forelimb movements are mainly influenced by the elbow joint and
not by the shoulder. Consequently a long humerus (upper arm bone) is strongly
correlated with performance in dressage horses, but rarely remarked on.
Elite dressage horses and showjumpers have flatter pelvises
than average riding horses, however again many horses have a flat croup
(muscles) and a steep pelvis (bone) so appearances can be deceptive. A flatter
pelvis assists pelvic rotation, and this is the most important determinant of
gait elasticity and jumping ability. On the other hand pelvic conformation does
not appear to affect longevity in hacking horses, and weakness here is often
compensated for somewhere else.
In the hindleg, a long, forward-sloping femur (thigh bone)
has been reliably and frequently shown to give both soundness and performance.
When we say that a dressage horse should be well “camped under” this
is the leg position that results from a forward-sloping thigh, which places the
hind well under the horse, aiding collection, balance and power transfer. It is
also possible to judge the femur’s position by marking both the point of the
hip and the horse’s knee, to allow you to judge whether the thigh bone slopes
forward or straight down. This is particularly important in hacking and riding
club horses where vertical femurs have been linked to leg and back problems.
Increases in height up to
around 17hh are linked to performance in showjumpers and trotters but not
dressage horses, and in all sports there is a massive variation in successful
horses. Sadly increased height also
comes with decreased soundness. Research confirms the adage that a short back
is a strong, healthy back, and good for performance, but it also predisposes
the horse to overreach injuries so overreach and solid brushing boots should be
considered.
Once we get to the neck, It’s
hard to objectively judge the actual “set” (attachment point), given
variations such as topline muscle, posture and wither height. A low set neck
can make it difficult for the horse to lift the forehand and so higher neck
posture is preferred for dressage. A longer neck can improve jumping
performance, acting as a counter-balance to the hindlegs, but a shorter neck is
common for dressage. Long necks can also increase fetlock problems, but only in
horses that race.
A wide throat latch (jaw) is
thought to facilitate breathing, although there is little evidence on this.
There is evidence that a wider-than-normal poll to throat latch distance is
often seen in elite dressage horses and showjumpers, and thought to help with
collection.
Many frowned-on conformational variables, including being
croup-high and lengths of cannon bones, do not affect the likelihood of injury
or disease, in the research at least. It’s an odds game, all we can do is give
ourselves the best chance we can, and then work with what we have. Other
factors such as temperament are just as influential, and for every solid
conformational rule, they’ll always be a
horse that beats the odds.
Previously we’ve covered how the equine back
works in Part 1, which focussed on the musculo-skeletal structure, Part 2 went into
unmounted exercises to increase balance, strength, range of motion and
stability. Now to complete the equine back biomechanics series we’re going to look a little at ridden exercises and how to
strengthen the back with your schooling.
There are plenty of popular ways to build your horse’s back,
topline and core muscles whilst riding – keep him engaged, ride up hills,
shoulder in, work on transitions, do cavaletti. When it comes to why, how or
what they actually do though things often get a little more patchy. In this
part I want to cover what exactly these exercises do, which ones work, what
muscles they target, how to get the most out of them, and how to design the
exercises that suit you and your horse.
As discussed in Part 1 carrying a rider is a massive challenge
to the equine spine, and muscle activation is required to lift the horse’s back
into a position where it can support a rider comfortably. If the horse attempts
to carry the rider with the spinal column rather than the muscles, this will
hollow the back and cause pain, and potentially spinal impingement and damage. In
Part 2 we discussed trying to activate core muscles and to rotate and flex the
spine to increase range of motion (flexibility), reduce spinal impingement and
to build muscle strength, making it easier for the horse to round and carry a
rider correctly. Then we looked at combining these exercises with challenges to
the horse’s balance to make them more effective. In the ridden horse we have
the chance to again rotate and bend the spine, through less of its range of motion,
but this time with the added challenge to balance and strength of supporting
the weight of a rider.
As with the groundwork exercises the model for our ridden exercises is Meikle Rustler, a Welsh Section D who belongs to Alison Brown and is ridden by her mother Gillian Brown. Rustler and Gillian currently compete at medium level dressage.
Walk
Many people who have used a horse walker have been surprised by
the amount of topline a horse can gain just in walk. In walk the horse’s spine
is very mobile. It must bend in all three axes – flexing as it rounds and
hollows, bending laterally to the side and axially, twisting along its length,
and for all three types of bending its range of motion is dramatically higher
at the walk than in the other gaits. This means that in walk the horse has an
opportunity to address and increase his range of motion and flexibility, target
and release the muscles that move the spine and by stretching the spine and
hence opening up the spinous processes you can prevent and minimise spinal
impingement.
Walking actively, particularly up and down slopes tones the
abdominal musculature and prepares the horse for increased engagement and more
challenging work. Walk is also the ideal pace for exaggerated stretches, such
as asking the horse to walk a five metre circle around a cone or imagined spot,
with his nose very low on a long rein and an exaggerated bend, flexing to the
inside and out, to target spinal flexion and mobility, helping to increase
range of motion and loosen any tight spots.
Walking the circle. The
spine twists along its length to allow the near hip to raised and the near
shoulder lowered, bends in flexion, and laterally to the inside.
Trot
In trot the horse’s spine is mobilised with less range of
motion than in walk. The spinal muscles are activated and the ventral core
muscles such as the abdominals are recruited to control the movement. This
makes trotting with a rider on board an excellent work out for equine back
health. If the horse carries a rider correctly in trot, the muscles and spine
should continue to gain in strength and flexibility.
The addition of trotting poles or cavaletti increases the range
of movement at the trot, so increases the intensity of the work out, balance
challenge and stretching.
Rotating the shoulder in
trot, whilst bending on a circle.
Cavaletti
Cavaletti is often used just as another word for trotting poles
or pole work. Whilst it’s important for showjumpers, it’s also important for
dressage horses, or any horse that’s planning to use its back to support a
rider. Traditionally cavaletti were fixed poles suspended between cross-shaped
wings, which could be rotated for variable height poles, but these days people
mostly mean “getting the horse to step over things on the ground, in walk, trot
or canter.” What it doesn’t mean is jumping, just literally stepping over poles,
sometiems raised, usually in sets. Cavaletti/poles are great, they develop the
paces, the rhythm, the balance, the cadence, whether you follow showjumpers
like Scott Brash or dressage riders like Charlotte Dujardin and Carl Hester
you’ll hear an exhortation to do cavaletti. However pole work doesn’t just give
you a big rhythmic trot because the horse gets in the habit of picking his feet
up, it actually improves muscle tone, balance and flexibility.
Trotting poles or cavaletti in trot increase flexion in all the
horse’s leg joints and increase the amount of movement through the horse’s
back. This builds strength in the muscles and flexibility in all the joints, as
well as aiding muscular control and coordination. Unlike using weighted boots, tactile
stimulators or pastern weights, trotting poles also increase the amount of
flexion at the hip, activating the horse’s hip flexors. Similarly horses do not
have an ability to habituate to the poles, as no matter how many times they do
them, they still need to clear the poles, whereas horses can learn to ignore
pastern weights and other worn stimulators.
The height of the limb flexions shown and the amount of spinal
bending is proportional to the height of the trotting poles, and so these can
be increased as the horse becomes more advanced and more confident in his
visual coordination and synchronisation.
A single pole or single poles scattered all over the school are
constructive, but you can also get a more sustained work out by asking your
horse to walk and then trot over sets of four or more poles. For a walk
distance you need to move the poles in to be about 0.9 metres (a yard) apart,
in trot they should be 1.2 metres (4 foot) apart. After that there is no real
wrong solution with trot poles, you can use your imagination to create
interesting patterns. You might start by placing four poles out evenly and
change the rein after trotting over them to approach from different directions,
and build up to riding a figure of eight with trot poles along the diagonals,
and then even a serpentine with trot poles along each short side. You can miss
out a middle pole, leaving a gap of 2.4m so the horse trots a couple of steps
between poles, or ask him to follow the line of a curved set of poles. As long
as the horse is trotting actively forward he will continue to improve his back
strength and health whilst finding the work interesting and gaining confidence.
Charlotte Dujardin and Valegro,
using cavaletti in the warm up at the 2015 European Championships (photo Barbara
Schnell)
Shoulder in, shoulder
fore and lateral work
In shoulder in the horse is asked to bend to the inside whilst
continuing to travel forwards with impulsion, leaving the horse travelling
“on three tracks” when viewed from behind. Shoulder fore is a similar
exercise but with around half the amount of bend to the inside, making it a
useful building block both in terms of muscle development and the horse’s
education, confidence and understanding. These exercises are normally initially
performed along a wall or rail, by maintaining the bend as you come out of a
turn. The lumbo-abdominal flexion involved in shoulder in and shoulder-fore
shorten and challenge the abdominal muscles, particularly the internal oblique
and hence this is another exercise which is very effective in strengthening and
rehabilitating the back. The horse builds his muscles as he uses them to stay
in balance, and so it is better to achieve a small amount of bend in a balanced
way than to push the horse beyond what he can achieve correctly.
Once shoulder in is established further lateral work like
haunches in, leg yielding and half passes can continue to challenge these
muscles. As lateral work targets one side at a time (and should therefore always
be done in both directions) it is particularly effective in muscle development.
Lateral work targets lumbosacral mobility and hindlimb engagement (iliopsoas),
the ability to lift the forehand (pectoral muscles), and the difficult to
activate spinal control (multifidus muscles), and so it is often seen as a form
of rehabilitation for the back, in both a preventative and curative sense. It
does however put a lot of strain on the collateral ligaments around the pastern
and hoof, so should not be overdone.
Hill work
Hill work increases the challenge by making the horse work
against gravity. Hills can be incorporated not just into aerobic fitness, but
into schooling and muscle building exercises. For example you can ride a slow 15m-20m
circles in trot on the side of a hill, asking the horse to lower his nose and push
up the hill using his extensors of the hip and back (gluteal and paravertebral)
and then control his balance against the slope when going back downhill using
eccentric muscle contractions of the abdominal and hip flexors. For an advanced
horse you might even put a pole or very small jump on the hill, and incorporate
it into the slow 20m trot circle, and trotting poles on the lowest part of the
circle to increase flexion and rhythm.
Whilst this type of hill work comes highly recommended as a
rehabilitation exercise for the equine back and core, and can greatly improve
muscle strength and coordination, you shouldn’t underestimate how challenging
it is for the horse and initially it should not be continued for more than
fifteen minutes. I find this a nice exercise, without the poles, to incorporate
into my hacks, just throwing in a quick trot circle or two on a slope, trying
to keep the topline extended, before I charge off up the hill.
Canter
Canter involves the flexion and extension of the back (in the
hollowing and rounding direction), but not the lateral bending or axial
twisting seen in trot or walk. Work at
canter therefore does not have the same level of benefit of stimulating the
deep multifidus muscles or increasing the flexibility of the spine or strength
of the spine stabilisers as some of the walk and trot exercises. This doesn’t
mean that you don’t need the same spinal strength to canter, just that canter
alone is not the most effective way to build total back health. Canter does have
a large amount of active lumbo-sacral flexion and so is useful in building
strength in the abdominal and sublumbar muscles, which in turn support the back.
In canter the abdominal muscles contract concentrically,
shortening the rib cage and rounding the back. Depending on the leading leg
either one oblique abdominal muscle or the other is the main support. As well
as maintaining the flexion in the spine the abdominal wall muscles (rectus and
oblique) cause the pelvis to tilt downwards, tucking the hind end under. The
sublumber muscles (iliopsoas) flex the hip joint lending impulsion and further
flexing the pelvis and back. Finally the thoracic sling works to lift the
forehand. This means that whilst it doesn’t involve the same range of motion as
trot and walk, a correct canter with the additional weight of the rider,
requires a lot of strength and effort from the horse.
In counter canter the abdominal and sublumbar (rectus and iliopsoas)
muscles maintain the position and flexion of the hip, whilst the abdominal
(oblique) muscles shorten the trunk, and so this requires a lot of strength and
coordination from the abdominal girdle. Counter canter is a great exercise for continuing
to build strength once the horse is sufficiently advanced, but if attempted too
early it can cause tensions and rigidity which is counter-productive.
Jumping is a very different movement from that of trotting over
cavaletti, involving a flight phase, so whilst canter poles can be an important
part of the horse’s education and muscle development, they are very different
as muscle training exercises from trot poles. Canter poles are more similar to
small bounce fences causing flexion of the spine and putting great demands on
the muscles without requiring too much impact. Bounce jumps or canter poles
selectively increase the strength of the thoracic sling and upper neck muscles
through the abrupt loading and lifting of the forehand between the jumps. During
the flight phase, spinal flexion comes primarily from the thoracic spine and
lumbosacral joint, due to contraction of the abdominal and iliopsoas muscles,
and induces stretching of the supraspinous ligament and erector spinae muscle which
run along the top of the spine. This makes this an effective exercise in
opening up the spine in this direction, but also means that the horse must be
very well warmed up before bounces are attempted to avoid muscle or ligament
strains. The hip flexors and abdominal muscles also work to provide propulsion for
the poles or jumps, but these are most challenged by the increased engagement
at landing in the bounce, required so the horse can begin to lift his front end
before the hind end has landed, rather than the effort of take off itself.
In general if a horse is carrying a rider, his back is already
working, and great progress can be made merely from hacking out in an active
walk, and occasionally asking your horse to stretch down, and to flex left or
right, to open up his spine. By including a variety of the exercises mentioned
here, you should have a happy, healthy horse that continues to increase his
ability to carry a rider, becomes more powerful and balanced, and either
recovers from or prevents any back injury or soreness.
Photography: Abby Cook Photography, copyrighted to Sian
Townson.
There’s growing research evidence that improving your seat off the horse is a great thing to do because a) it’s effective – who doesn’t want a better seat – and b) you can correct muscle patterns more easily when you and the horse aren’t encouraging each other’s asymmetries. Get your core stability correct, it’ll be easier to get your horse correct. You can spend hours fighting not to collapse at the hip, to sit straighter, deeper, drop your thighs down, toes in and get the horse engaged, to stay with him over jumps, but it’s never going to be as effective as just correcting your own muscle weakness before you start.
Also in exciting news I broke my ankle and so unmounted exercises are quickly becoming my thing. A broken ankle is pretty common in horse riders so this should also help my fellow sufferers whose days are currently filled with repeating “can I ride yet?” I can’t get you back on the horse yet, but at least we can make sure that when you do you haven’t lost all semblance of riding ability, and might even have improved a bit. Might come in handy if your horse has been laying off while you recuperate!
Step 1) Caring: I haven’t broken anything, why do I need to strengthen my own core?
The rider’s seat is an active process. “Sitting on a horse” sounds passive but an engaged seat requires a lot of muscle strength and coordination. Phrases like “go with the movement” are not that helpful as it makes you feel like you just have to find the right kind of wibbly wobby relaxation.
Find something now: a bouncy ball, a sweet wrapper, anything lying around that you can put in your hand and trust to stay completely relaxed. Now, with your object on your palm, bounce your hand sharply up and down, and see how fast you can go whilst it stays in a deep contact by just going passively with the movement. How’s that working out for you?
Imagine an enthusiastic horse bouncing along in trot or canter. Gravity & relaxation are not enough to keep you in the seat when the moving horse bounces you upward. When the horse reaches the downward part of his bounce gravity will pull you back down too but only once you’ve completed your upward trajectory – shortly after the horse stops pushing you up. This means you’ll be catching up with the horse’s back, coming down onto the horse’s back as it starts to re-ascend, with a painful bump. Then he’ll tense up, you’ll tense up, we’ve all been there. Nasty. If you actually tried the bouncy hand exercise, you may have also discovered the urge to slow down to reduce bouncing. Or as we call it “lazy” or “behind the leg”.
You may have known a horse that can go the other way too – rush at a jump unless held by your core. You can try holding them with your arms, good luck with that! To be honest it’s hard to do anything with your arms until you have a stable core anyway, never mind keep your hands soft and following the horse in trot or canter or over a jump.
We the ambitious riders who’d like to own happy horses, want even more than a deep seat that stays on the horse, we want to control our muscle use so that we can move with the horse, even shift our pressure and tension and use it as an aid. No other sport attempts to reach this level of fitness, strength and coordination by just doing the sport. We need to release muscles we’d naturally tighten and tighten muscles we’d not normally use. We need exercises.
Step 2) Addressing the muscles Iliopsoas: Psoas & iliacus.
The iliopsoas group of muscles is the deepest & arguably the most important part of your core. It’s made up of the psoas major and iliacus. Most people can’t be bothered to say iliopsoas, so they say psoas (the ‘p’ is silent) and mean the whole group, leaving others to get confused and starting to wonder if iliopsoas is yet another muscle. Don’t let it bother you. Similarly some people get het up about psoas minor, but in bipeds (that’s you) it’s so small that it’s often absent, so functionally it’s not the place to focus. We’ll worry about psoas minor when we talk about a [four-legged] quadruped.
Psoas (major) runs from the spine (lumbar vertebrae) to the inside of the femur (or thigh bone), so it flexes the hip and turns the leg out. Ditto iliacus, running from the pelvis to the same femoral attachment, having much the same effect. If you sit in a chair, car seat or anything that leaves you in that thighs up position for an hour or two, your iliopsoas shortens and contracts. So if you have or had a desk job rather than a sitting-on-horses job you’re likely to have issues here. You may even be sleeping for hours every night in a lovely cosy foetal position – or worse, with one leg bent. I’m pretty good at guessing someone’s sleeping position by looking at them on a horse.
If you contract your psoas sitting on a chair, you stay on the chair, albeit with back pain. If you contract your iliopsoas sitting on a horse, you end up with a forward-tilted pelvis, a hollow back (and a hollow horse), and a flexed and outward-turned hip. This means that you can’t get the thigh down or the knees to turn in, because your hip flexors and rotators are jammed on, and to avoid tipping forward you’ll try to sit up by hyperextending & bracing the back. You’re working very hard co-contracting muscles to fight yourself but all you can get is tense, stiff and nasty. Your horse is actually being asked to hollow and you look like a frog.
Even within the very elite, Carl Hester for example has noticeably tighter iliopsoas muscles than his pupil Charlotte Dujardin and so has to work harder to get the same results.
If you’re really unlucky you spend a lot of time sitting in a chair asymmetrically. If you pull more on just one psoas, just on one side, you bend the spine & hence trunk to that side, collapse that hip and are left wondering why you just can’t sit straight on a horse.
If you want to be able to move synchronously with the horse so, for example, in walk your pelvis rocks side to side as your horse does, allowing him to use his back then you need to use your iliopsoas correctly, from a relaxed state.
The iliopsoas group are your most powerful hip flexors. If you’ve ever done knee ups or sit ups thinking you were strengthening your abdominals, chances are these are the muscles you were working. Good news is once you’ve released your iliopsoas muscles your abdominals and inner thigh will naturally strengthen as they’ll actually have to do some of the day-to-day work themselves.
ironically most people’s iliopsoas are both
both tight and weak, because they’re not using the full range of movement. There are lots of exercises online for strengthening the iliopsoas/psoas. Don’t do them. First we want to lengthen and release. There are a lot of yoga videos online on “psoas” release and most of these are very useful.
As the iliopsoas is so close to the diaphragm just breathing can help, and that’s one of the reasons that breathing correctly has such an effect on your horse. Similarly if you tilt your pelvis posteriorly, as if you were trying to tuck your bottom under you and round your lower back, your psoas will already start to stretch and you may feel any lower back pain ease.
It’s very hard to stretch a muscle before it’s warmed up or contracted (despite older advice telling you to stretch before you start exercise) so the best way to start with your iliopsoas is to lie on your back, bring one bent knee up to your chest so that the hip flexors are really short and active. In that position hollow and round your lower back so that you can really target the muscles. Then slowly lengthen your leg out from there until it is flat on the floor and you’ve stretched as tall/long as you can be. Hold for a few seconds. Repeat this a few times on both sides, seeing if you can feel a longer stretch each time.
The second exercise to try is half kneeling and is a little similar to a lunge. Kneel on one knee with the other foot on the floor in front of you, as if you’re going to propose. Then keeping your body upright try to push forward slightly onto your front leg opening your trailing hip to leave the bent leg behind you. This is close to the crescent lunge in yoga, and stretches the iliopsoas of the trailing leg. Same effect can be reached standing up, by putting the front foot on a box/wall/sofa, if like me you find quick standing exercises easier to con yourself into. Just please don’t fall over.
With both exercises repeat 2-4 times both sides, 3 or 4 times a week or as needed.
There are plenty of variations of these and other exercises. It’s ideal to just to think about where the muscle is, and just move in a way that stretches it within your own current ability.
Abdominals
The abdominal muscles get a lot of attention: they’re right on the surface, make your clothes look good and more importantly for us they’re certainly a big factor in making a rider effective. The effortless riders that seem to be doing nothing are using a lot of abdominal muscle strength. Go on, scroll back up to have another look at Charlotte, relaxed but certainly not passive, using a massive amount of abdominal tone to keep Valegro off his forehand and her own body in an effective position. This, along with the pelvic floor, is what is helping pull her down into the saddle even though her horse has pushed her up, and keeps her still so her aids are clear and hands independent.
The tricky part in trying to strengthen your abdominals is that many traditional exercises make it easy to cheat and just use your iliopsoas muscles, leaving you with even more back ache. We’re already great at shortening the iliopsoas, and it’s making us sucky riders. So instead of sit ups and crunches let’s engage core stability and make the abs work in a targeted, lengthened position. If you don’t have a broken ankle you can start the infamous plank – on your hands and knees or hands and feet, as straight as you can as if you’d just completed a push up, but just hold it. Start with ten seconds or two minutes, whatever feels right. Tomorrow you can go ten seconds longer. It’s important to stay within what feels comfortable as if you try to hold it for too long you’re likely to lose the straight back, neutral spine position, and won’t be targeting the muscles as well as you could. If you’re not ready for a full plank you can always use an incline – arms on a sofa or even the wall rather than the floor.
The second exercise to try is similarly starting on your hands and knees, straight back, knees directly below hips. Then lift one hand and one leg straight out and hold it. As with the horse’s exercise the abdominals are working dynamically to keep you stable and balanced, making this a very effective exercise. Similarly if you lift one leg from the plank pose you’ll add a lot of extra challenge to the exercise. In both cases don’t forget to switch and work both sides!
Good news
The great thing about core muscles is that they are unusually quick to train, and not too hard to maintain. The hard part is just the getting started, and you should see results as quickly as the second week.
There is a little more to say about core strength and stability but as ever I’ve already gone on long enough and both family life & paid writing are calling, so I’ll return to this topic in a Part 2. Worth mentioning though, that whilst I’ve used dressage pictures, the core is particularly relevant to the showjumper as it is what keeps you in balance over a jump in a fold. If you struggle with getting ahead or behind your horse, over a jump or in any discipline, or getting him to engage or respond to your aids, a lack of core stability is usually to blame. Ditto ending up exhausted and out of breath when you ride. Often people are just tired because they’ve mostly been fighting themselves. But now we’re going to fix that. Yey us.
The previous post covered a fair bit about the back’s structure, bones and the issues of carrying a rider. Now I’ll go a little more into the function of the soft tissues and groundwork exercises (keep scrolling) and eventually in Part 3 we’ll get to more on spotting and addressing asymmetry, ridden exercises, and my personal favourite cavaletti.
Musculature
The muscles of the vertebral column can be divided into those running deepest next to the spine, including the multifidus, and those nearer the surface, including the longissimus and iliocostalis. The deepest multifidus muscles run along 2 or 3 vertebrae each, overlapping all the way and connecting the vertebrae to provide support, stabilisation and motor control. They have a lot of innervation so give the feedback that keeps track of spinal position and motion. The more superficial muscles are larger, less innervated and provide gymnastic motion – extension, rotation and lateral motion of the spine. As we covered in Part 1, the interlocking of the vertebrae means that the spine doesn’t really have the ability to bend laterally without also rotating, so these movements require the entire spine, and very little bending at any one single joint.
As well as these muscles that run along and above it, the spine is supported by the ventral muscles running beneath it (flexors) including the abdominal muscles and the sublumbar muscles (iliopsoas muscles). By finding an equilibrium between the two sets of muscles the horse is able to move efficiently by holding the spine in enough tension to support a rider and transfer power from the limbs. The pelvic stabiliser muscles such as biceps femoris and the gluteal muscles help with balance and power transfer from the hind legs and are essential for collection and jumping.
Finally the thoracic sling muscles, such as the trapezius and pectorals, hold the forelimb onto the trunk, and hence when the forelimbs are on the ground can affect the position of the trunk.
If only one side of the thoracic sling is active the position and straightness of the shoulder is affected. Muscle tension through both sides at the same time lifts the withers and sternum, and helps create an uphill horse, lifting the weight off the forehand and rocking it to the hind end.
The thoracic sling is also anchored to the rib cage and used in breathing. This is fine when the horse is still, but when the horse is cantering, for example, he must breathe in time with his stride, and hold his breath when he jumps. Imagine then the problem of a horse trying to relax but not ridden in an regular rhythm.
The model for our groundwork and ridden exercises is Meikle
Rustler, a Welsh Section D who belongs
to Alison Brown and is ridden by her mother Gillian Brown. Rustler competes at
medium level dressage and practises stretches and groundwork exercises
frequently and so has a large amount of muscle tone, making it easier to spot
his muscles activating in response to the activities. Here are some sample pictures of Rustler, who I’ve failed to stand square. I hope they give you an idea of how you can spot these muscles activating during the groundwork exercises discussed below these pics.
Standing ready to
start with muscles relaxed.
Thoracic lift
Stretching
Groundwork exercises
There’s a lot of support in the research for using groundwork exercises to strengthen the back and mobilise the joints both before introducing ridden work to prepare for carrying the weight of the rider, and throughout the career, particularly after injury or time off. They help to improve strength, self carriage, balance, flexibility and the stability needed to collect or jump.
Injured or weak back muscles often do not self-correct and need to be specifically targeted or the horse will attempt to find other ways to compensate, usually by overusing the opposite side, increasing their own asymmetry rather than addressing it. Groundwork exercises can build these muscles back up. Similarly stiff joints and the spinal impingements can often worsen due to continued contact if the joints are not adequately opened and stretched, and range of motion maintained. In the more advanced horse these exercises can improve balance and power needed for collection or jumping.
Groundwork exercises can be roughly divided into three types: mobilising the joints (horse yoga), activating and strengthening core muscles (horse bodypump) and improving dynamic balance (horse pilates). All three are important for a healthy horse. A young horse that hasn’t yet carried a rider, or a horse recovering from injury, would benefit greatly from building up his muscle tone and spinal alignment first but should be careful not to push it too far. At the other end of the scale a horse competing at high-level dressage will need to continue to build these muscles unmounted, but will need to increase the difficulty of the exercises to really challenge his muscles and balance.
Mobility (Stretches)
When a horse is challenged to stretch his spine it opens up the spinous processes and reduces the risk of impingement, and builds the small multifidus muscles that control and stabilise the spine, but often become wasted or uneven as they are not easily activated.
It’s common when doing these exercises that a horse find one side easier than another, and that’s OK, that’s partly why we’re doing them. Better to stay within the range of motion the horse can achieve correctly, then push him too far and encourage him to cheat by stepping or tilting his head. Keep an eye that his ears stay level, and accept that his flexibility, strength, balance and symmetry will improve with repetition. It is not normally worth forcing a horse into a position using manual pressure, as the horse needs to use his own muscles in order to strengthen them, and you risk pushing the horse beyond his current comfortable level of movement if you force it yourself. As with yoga, each stretch should be slow and relaxed, and aim to hold the end position once it’s achieved for a few seconds.
Using a carrot stick or other favourite bait the horse can
be asked to follow the carrot and do the following stretches. Firstly, start
with the stretches which stimulate flexion of the neck muscles, work on his rounding and abdominal muscles and
extend the spine, opening up the processes.
Using the carrot he should be tempted to:
1) bring his chin to his chest,
2) bring his chin down to and/or between his knees and
3) bring his chin down to and/or between his fetlocks.
Start by aiming just to ask the horse to reach towards these
positions, and then with a bit of practise you’ll be able to go further into
the stretch, for example moving his chin between and beyond his knees rather
than just towards his knees. If necessary having a helper put a hand on the
noseband will encourage the horse to keep his head straight, but remember to
tempt him rather than pull him into position.
The second type of stretch are the lateral bending exercises.
These show up asymmetry and further challenges the spine stabilising muscles
and the horse’s rounding and bending muscles. These can be tested by asking him,
by following you with his nose, to one side and then the other, from the front to reaching backwards and
downwards to:
4) bring his chin to his girth,
5) bring his chin to his flank and
6) bring his chin towards his hind fetlock.
It may be helpful to stand next to the horse and ask him to
reach around you to encourage an even bend through the neck and spine. These
exercises can be very revealing as without the added complications of a rider,
and with the motivation of a carrot or other treat, it is much easier to see if
there is a marked difference between the left side and the right. If you have a
helper it can be useful to have them stand at a safe distance behind the horse,
ideally on a stool, to see if the horse bends evenly through his body to both
directions. If you’re not sure if there’s a difference then they’re probably
isn’t, but it helps to take a photo of each direction to help compare them.
Occasionally you’ll see a horse who tries to keep his body straight and just
use his neck on one side, but is happy to bend his entire spine in the other
direction. This is the type of sign of injury or soreness from saddle fitting
or ridden work that may needs further investigation and is worth highlighting
to your vet in the first instance. Every horse will however prefer one side to
the other, particularly if he’s not been challenged to build these muscles
before. An uneven ability to each side but with similar technique is not
necessarily any cause for concern and should improve with practise as these
exercises will greatly increase his range of motion. The horse may initially
attempt to “cheat” by stepping around to face the carrot that he’s
reaching for. It is not worth over-correcting this, after all it’s a fairly
efficient solution to the problem of needing to stretch and wanting to reach
the carrot. Just patiently put him back into position and start again, using a
wall or second person to help hold his hind end still. One he realises which
behaviour wins the carrot he’ll be more compliant in future and eventually
you’ll be able to work in the field, and won’t need to keep lining him up with
the wall.
There are entire books on carrot stretch technique, and they give you an insight into the most accurate targeted activation of specific muscles, but be encouraged that if your horse is moving under his own muscle power whatever you’re doing you will not be hurting him. Even if your technique is different from the next person’s, or doesn’t target the muscles you had in mind exactly as accurately as it could, your horse is still benefiting from doing a stretch.
Correct rounding
Rustler “cheats”
by stepping forward and tilting his head. He still achieves rounding but he has
reduced the difficulty of the exercise.
Lateral bending to the flank. Here we
have a little too much twisting of the neck, whereas ideally his ears should be
level with each other.
Balance
When a horse is forced to keep his balance against a pushing
hand or due to a lifted leg, he must work his core muscles correctly to
maintain his position, just as we would in a sit up, pull up or push up. Young
horses can even struggle to even keep their balance when one hoof is lifted,
and this can be interpreted as irritability at having hooves maintained when
often it is just anxiety combined with a lack of muscle tone and experience
with this sort of exercise.
If the stretches listed above are combined with a lifted
hoof the horse must work to keep his balance, further activating his core
muscles and improving his muscular control. This increases the difficulty of
the exercises so should only be introduced once the horse is already
comfortable with the stretches, and is used to having his hooves picked out.
A hand pressed on the horse’s shoulder or chest for a few
seconds will force him to work his core muscles to maintain his balance. You
may not see him move as you press, but if he’s working correctly you should
notice him rock forward again once your hand is gone. In the advanced horse,
like Rustler, you can combine this with a lifted hoof to increase the
difficulty. You can lift either the front or back leg, but always push towards
the tail, or the opposite hind hoof.
At the other end gently pulling on the tail to one side then
the other can force the horse to resist using (and building) his pelvic
stabiliser muscles. The pelvic stabilisers are the muscles that allow the power
to be efficiently transferred from the hind legs, and help to keep the horse
balanced and off his forehand. As with the chest press, the aim of this
exercise is not to move the horse, but to encourage him to activate his muscles
to keep his balance and resist the movement.
Rounding with a lifted hoof.
Balance exercise, pushing
on the shoulder with a lifted hind leg.
Strength
For further strengthening work of the core muscles, you could look to sternal lifts and “butt tucks”.
If you run your hand, pressing quite hard, along the sternal ridge that is the central line running underneath the horse between his forelegs, past the girth, and back towards the back of his stomach, you should see the corresponding parts of his back lift as he tightens his core muscles. In a less toned horse the difference is less obvious you should be able to see some effort from any horse. The amount of pressure required varies, particularly the first time whilst he works out what you’re on about. You’ll know when you have it right. On some horses it can be easier to use the blunt end of a
hoof pick rather than fingers to increase the targeted pressure to start with. Rest
assured that you are not hurting the horse, particularly if he hasn’t yet
responding by moving away from the pressure.
Activating the sublumbar and abdominal muscles to tuck the hind end under is an excellent strengthening exercise but can take a bit of trial and error. Stroke up the spine from the top of the tail with your thumb until the horse lifts his back, engaging his hindquarters. In an advanced horse you (and a friend) can do this at this same time as lateral bending and/or the thoracic lift. As with the previous exercise, you will be able to spot a
reaction when you get it.
In the very strong advanced horse you can combine these exercises with the balance exercises above, by lifting a hoof or adding a backward push.
Thoracic lift
Your horse may look at you with great confusion when you
start doing all these exercises, but they usually figure out what is required
fairly quickly. I find that in my horses, once they’ve tried the exercises and
come to associate them with treats, they are very enthusiastic about them. Mine
even occasionally offer an unprompted stretch in the hope of winning a prize.
You may also find that as your horse gets more experienced you can then do
several stretches to the reward, rather than having to load up on so many carrots
or pieces of his dinner.
I’ll post a photo series with more detailed guidance on groundwork exercises for people who are interested soon. I’m waiting for a magazine article or two (by me) to come out first so that I don’t scoop myself. In Part 3 I’ll cover ridden exercises, asymmetry and cavaletti.
Photography: Abby Cook Photography, copyrighted to Sian
Townson.
Kissing spines, straightness, and the equine back: how does the back work, and how do you keep it strong & healthy?
This series of posts covers the structure and function of the healthy and pathological equine back, how to detect soreness, recover from injury, and improve strength. The equine back is a massive topic, and one that research is only just starting to reveal. This is a dramatically under-researched area, but recently the field has moved forward so fast that we have been able to discount many theories that once seemed very credible. This can make life a little confusing, but at least we do now have some good evidence behind our understanding of the back.
First let’s get the basics down.
The back, like all musculo-skeletal structures, is made of hard tissue (bone and cartilage), and soft tissue (muscles, tendons, ligaments and connective tissue). If you like tendons you’ll love my last post (link here) but for now let’s start with the bone: the spinal column.
Anatomy: hard tissue
The spine is made up of vertebrae, and these little building blocks fit together like lego. They run from the head to tail and have different shapes according to their region: vertebrae can be cervical (neck), thoracic (with ribs on), lumbar (small of back, behind the saddle) and sacral (fused region running through pelvis) and coccygeal (tail). For now let’s ignore the coccygeal vertebrae of the tail. Trying to hold your spine stiffly enough to carry a rider is hard, most animals can’t, and with all that to cover your horse’s ability to swat flies is not the crocodile nearest the boat. The tail is not completely irrelevant and can give us clues, but let’s address those another day.
The number of vertebrae in any spinal region can vary, but the total number in the spine (without the tail) is pretty constant. Long backs are normally due to long vertebral bodies rather than having extra vertebrae. Each type of vertebra has a distinctive shape, although weird transitional vertebrae with characteristics of two adjoining areas are quite common. Each part of the spine is adapted for different functions and brings its own unique problems.
The spinal cord, a bundle of nerves carrying the messages from brain to body, runs down the spinal column through a line of holes called the vertebral arch. The arch is roomy compared to the cord so normal movement doesn’t compress it, even when the spine flexes and rotates the cord is protected in this bone-encased canal. You wouldn’t know it’s there unless you needed to block a nerve, but osteoarthritis or fractures can narrow the canal and crush the cord, leading to seemingly-unrelated neurological symptoms.
The nerves branch off the spinal cord and exit through holes called the Intervertebral foramina, along with blood vessels and various other things. Occasionally a second pair of holes, the lateral foramina carries nerves. These holes are created if the caudal arch calcifies to divide the foramina and pinches on the spinal nerves. This means that even spotting the existence of lateral foramina justifies looking for spinal impingement.
Rising out of the vertebrae like sharks’ fins are the dorsal spinous processes (DSPs, black arrows in above). There’s a change in inclination of the DSPs (Picture b, below), as their role changes from supporting the soft tissue pull of head, neck and forelimbs (Picture a) to supporting the hind legs (Picture c). DSPs normally have spaces between them and usually don’t come into contact with each other. In some cases on lateral x-rays the spinous process can look like they are overlapping, but even then they are often not actually touching as they are not quite in the same alignment – i.e. in an side-on X-ray they look like they overlap, but in fact are out of plane i.e. one is to the left of the next, and neither is in the central sagittal plane. Sometimes, however, there is contact, and remodelling, and even false joint formation. This is the dreaded kissing spines.
The vertebrae also have protuberances called articular facets, and these interlock, stabilising the spine and through their joints allow different movement at different regions. Thoracic regional mostly allows lateral bending and axial rotational, lumbosacral mostly about dorsoventral motion (rounding and hollowing). An incredible 83% of horses have asymmetrical facets, and yet we’re surprised if one rein is easier.
The final fins coming out the spine worth noting are transverse processes. These provide stabilisation for the spine and lever arms for muscle attachments. In horses these have their own joints between them but not at every vertebrae. The amount of these joints not only varies between horses but these too are asymmetrical, which is pretty weird and probably something you should think about. The only other mammal this variability is seen in is the rhinoceros, and no one ever tried to make a rhino into a symmetrical athlete. Intertransverse ankylosis, a sort of arthritis in these joints, is really common, found in 50% of horses. It’s not clear whether this actually causes back pain. Watch this space, and we’ll see how the research pans out on this one.
The sacrum is made of five vertebrae that fuse at around the age of five years, and two centres of ossification (growth plates) that also fuse at 5.5 and 5 years, give or take 1.5 years. The sacroiliac joint is where the vertebral column articulates with the pelvis, and where the push from the hindlimbs is communicated to the spine. It’s a specialised shape to cope with transferring this much load – most moving joints have interlocking shapes that help hold them together but this joint is made up of flat surfaces held together entirely by very strong ligaments, and yet is a key site of flexion/extension in athletic function. As a result this is a common site of problems and pain, with degeneration often undiagnosed until post-mortem. In the pictures below of Sox jumping, the sacroiliac extension then flexion is seen, just behind the numnah.
Growth plates in the pelvis fuse around 5.8 years. By around I mean again +/-1.5years, and give or take 1.5 years is a lot of variation. When we give a 1.5 year standard deviation (+/-1.5years) this means that a 4 year old horse may already have completed this growth, and equally a 7.5 year old horse that had not would still be in the normal range. Tuber sacrale and tuber coxae are the highest and widest points of the pelvis respectively, and also the last to fuse. This means that they can suffer a little of knocked in the young horse. Otherwise, contrary to popular belief, I wouldn’t lose sleep over unfused bones.
Disc problems such as slipped discs are common in humans and dogs but not horses, who only have a small amount of disc material between each vertebrae, and a relatively immobile spine. Very occasionally disc degeneration is seen, but almost never herniation (slipped discs).
Conformation
A flatter pelvis has been associated with improved soundness (trotters), and improved performance (showjumpers and dressage) and yet a less flat pelvis (higher L5 angle) is linked to a higher range of motion and tendency to flex and extend this region more. Using a greater degree of motion in the region seems to push the supporting structures to the limit and cause more injuries. Other conformational aspects such as length and curvature of back contribute to the amount of motion, and so risk of injury. The vertebrae are interlocking and any relative movement causes a strain on the structures.
Soft tissue
The movement and support of the back is achieved by many layers of muscles, and there are many ways to group them. The muscles of the vertebral column can be divided into those running next to the spine (juxtavertebral muscles) and those nearer the surface (paravertebral muscles). The juxtavertebral muscles or intrinsic back muscles connecting the vertebrae provide support, stabilisation and motor control. These muscles have a lot of innervation so give the proprioceptive feedback that keeps track of spinal position and motion. The paravertebral muscles are larger, less innervated and provide gymnastic motion – flexion, rotation and lateral motion of the spine. The interlocking of the vertebrae means that the spine doesn’t really have the ability to bend laterally without also rotating, so these movements require the entire spine, and very little bending at any one single joint.
The spine is supported by the muscles that run along and above it (extensors), and the ventral muscles running beneath it (flexors) including the abdominal muscles and the sublumbar muscles (iliopsoas muscles). By finding an equilibrium between the two sets of muscles the horse is able to move efficiently by holding the spine in enough tension to support a rider and transfer power from the limbs.
Factors contributing to injury: carrying a rider
Carrying a rider’s weight can lead to many spinal lesions including impingement of the spinal processes and arthritis of the facet joints. Carrying an uneven rider and trying to do sports can add muscle strain to these.
Walk, trot and canter require a lot of passive movement from the spine, with the muscles mostly act in a restraining fashion. As the limbs move the spine extends and twists most at the points of common pathology. The precise spinal movement varies a lot between horses (large interhorse variability), but is very consistent in any one individual (intrahorse). Extension and twisting are particularly seen in diagonal support at trot and canter, where strong hip extensor muscles and abdominal muscles are essential to restrain the movement and avoiding strain on spine from movement.
When a horse takes a rider the weight of the rider naturally hollows the horse’s back, putting it under threat of damage such as spinal impingement. Muscular effort is needed to round the back and to stabilize it in this position, making it more able to carry the rider’s weight, to step under with the hind legs, and to transfer the push from the hind legs effectively. To achieve this the horse needs a large amount of muscle tone. For example abdominal and short back muscles are also particularly important for stabilising the back to allow propulsion from the hindlegs for collected movements, flying changes, and jump take off. In dressage horses pectoral muscles control the descent of the forelimb during extension – and can become overstretched and damaged if extension is not controlled. Similarly as the horse has no collar bone, movement at the shoulder, including bending or landing, requires a stabilized spine for the shoulder muscles to anchor to. The muscles of the shoulder are particularly common but overlooked sites of injury in the showjumper – taking the brunt of the landing by supporting the trunk in a sling of muscle between the forelimbs. The same shoulder muscles, particularly the trapezius and rhomboid muscles, can be common sites of anxiety related tension. The jumping pictures are of Sox an outwardly calm but inwardly worried showjumper, with me his slightly podgy, unbalanced rider. His trapezius gives him a lot of trouble.
Reducing the risk of and recovering from injury
Symptoms of back-related problems can vary from none to dramatic. The majority of horses with back pain show only poor performance and many sacroiliac problems are only diagnosed post-mortem. Horses might show “behavioural problems” such as rearing, bucking or avoiding the saddle or rider in the case of kissing spines, and restricted range of motion in the case of arthritis or muscle lesions, muscle wastage or hind limb plaiting in the case of sacroiliac pain, etc. Quite often back problems get missed, just because the symptoms are so diverse. Even when a back issue is suspected it can be hugely complex to diagnose.
During episodes of back pain the multifidus muscles, running along the spine, are selectively affected, and lose symmetry and size. Even after pain resolves, they do not naturally return to their previous size without intervention. This is turns increases the trouble that the horse is having, as they are no longer able to support the problematic area effectively. It is entirely possible that the cycle starts with localised wasting of one muscle, which then fails to stabilize the spine effectively causing back pain, which in turn leads to muscle spasm, shortening and disuse. In humans performing exercises to strengthen these muscles reduces long term recurrence of back pain, and it’s been shown to that strengthening the muscles that move and stabilize the spine has similar effects in horses.
Research has suggested that there’s benefit in starting core exercises of these spinal support muscles – of the spine abdomen and back – before the start of ridden work, and continuing them throughout the horse’s career, in particular during lay off or after injury. Many back injuries occur as the horse has no means of communicating a minor injury or stiffness, whereas a human with lower back pain would be allowed to rest. Jean-Marie Denoix is fond of saying both “engagement is the only way of exercising a horse without making it suffer” and “no abdominals, no back”.
Core mobilization exercises in horses include the exercises commonly referred to as carrot stretches – asking the horse to reach forward, down, and to his side using a target such as a carrot. On first inspection these stretches don’t appear to do much and hence these were much derided when introduced as ways to increase suppleness and relieve boredom in the stabled horse. However over the last few years research shows that these exercises require the horse to use his spinal muscles to maintain his balance whilst he holds each new position and so both strengthen these muscles and correct asymmetry. As such they are some of the most important tools in the rider kit. To start with the horse is asked to reach his head to his chest, between his knees, to his elbow, and to his stifle. These stretches target different muscle groups and open up different facets of the spine. In other cases a hand pressed on the sternum, side or rump of the horse as resistance can encourage muscle use. I’ll cover exercises and mobilisation in more detail in the next post.
Mobilisation exercises can be combined with work on a slope to develop strength and suppleness through the back. This is not necessarily the aerobic fitness work of cantering up hills, but for example a slow deliberate trot on a 20m circle, ideally the lunge or with a standing rider so that the back is free, using both the slope up and down hill, and even poles to encourage cadence and rhythm. The horse’s topline needs to be extended, nose lowered. Side reins aren’t going to help, although a chambon can encourage stretching and understanding. This is the type of exercise that when used twice a week can show a great improvement in horses with weak or damaged backs. As with all strengthening work, little and often is the most useful approach.
Back problems can come from a variety of causes – lack of warm-up, rushing the undeveloped horse to attempt activities or movements too early, asymmetry in the rider, “natural” asymmetry in the horse, tweaks during activity that aren’t allowed to rest. Problems in the limbs frequently lead to problems in the back, as any woman that has tried to walk in heels will tell you. The difference is that in horses we need to spot and correct these problems through our own vigilance.
Part 2 and Part 3 will cover the back musculature, function and dysfunction in more detail, detecting muscle soreness or weakness, the effect of training aids and discuss how to apply hill work, exercises, stretches, therapy and massage. Please note that this site constitutes discussion of athletic development and performance, and does not give clinical advice.
My last post covered a little about tendon structure, hysteresis and crimp and what all this means for the equine digital flexor tendons (link here). This time I’m going a little deeper into how tendons work, tendon creep, and how to make tendons (and ligaments) stronger. The main tissues I’m going to talk about are the superficial digital flexor tendon (SDFT), deep digital flexor tendon (DDFT), and the suspensory ligament or third interosseous muscle
(SL), which despite its confused names is usually classed as a tendon. These form the suspensory apparatus, and I’ve talked a bit about what they do in the last post, but I’ve put a picture above so that we’re all on the same page (from one of my previous papers Lawson et al., 2007). The picture also has the main bones of the distal limb marked – the third metacarpal (MC3), proximal sesamoid bone (PSB), distal sesamoid bone (DSB), P1, P2 and P3.
Tendons are made up of a lot of different proteins, but the two main ones are collagen which resists loads and elastin which allows stretching. In tendons the collagen fibres are mostly parallel. This makes them effective in resisting forces from one predictable direction, and in turn being exposed to unidirectional forces encourages fibres to align and be more parallel, and we have a happy cycle. The collagen fibres in ligaments are less organised, as they can be pulled from more than one direction (see picture below of my lovely collateral ligament model). This makes ligaments weaker if we’re comparing stretching in one direction. In tendons and ligaments, collagen fibres are crimped when not under load, so they have an increased ability to lengthen and resist force without failing when they’re aligned in the right direction, more about that in the earlier post.
The amount a tissue can stretch compared to its original length is measured using strain (the ratio of new length to original length). The other thing we’re fond of measuring is stress, which is the load it’s exposed to as a proportion of its size (force per area). The amount a tissue will deform for any given load (stress divided by strain) is called the modulus of elasticity. This varies between tendons, and is one of the properties that will determine ultimate strength. The stress vs strain graph pictured shows the effect of modulus of elasticity on point of failure (ultimate tensile strength). The more a tendon can lengthen, the more load it can take before it fails.
So as tendons are not equally strong in all directions (anisotropic),
the chance of them failing partly depends on the direction of the force and partly on the tendon’s (modulus of) elasticity. The final important factor is how quickly a force is applied (viscoelastic properties).
Creep is the effect that allows tendons to progressively lengthen under the same force which has the effect of releasing tension. It’s the reason you can get further if you hold a stretch and keep stretching. Does it matter? Well, it means that tendons are great with constant pull, lousy with sudden impact. This is the reason that I talk a lot about the initial impact spike of hoof hits ground, and its effect on the digital flexor tendons, despite the fact that peak tendon strain occurs in mid-stance (for SDFT and SL) or end-stance (DDFT). Sudden changes in length such as a tendon struck (and stretched) by a hoof or an unexpected footfall from uneven ground – whether that’s rabbit holes or inconsistent arena surfaces, this is what causes a lot of injuries. I have a deep resentment of inconsistent/patchy all-weather surfaces.
To try and understand how to develop stronger tendons, a lot of research has compared foals raised in stables and given different formal exercise regimes with those kept in fields. Pasture-kept foals, that live out 24/7, consistently grow stronger tendons not just in the short term but actually develop tendons with more collagen fibres – i.e. with a higher potential strength that they can achieve through training. Whilst increasing exercise in stable-kept foals does lead to stronger tendons, in all studies 24/7 pasture exercise induces more strengthening changes than controlled exercise combined with stabling. Foals that are shifted from box-kept to being field-kept will to some extent catch up, but are unlikely to ever reach the same extent of collagen structure and tenocyte metabolism as foals that have always been in the field. It’s worth mentioning that in research tests horses that live in but have access to 2-4 hours of field time a day are considered to be stable-confined. You just can’t get the same amount of stimulation in 3 hours as you can in 24. Similarly pasture-kept horses are rarely in “natural” conditions, as pasture-size and herd-size tends to be limited, which reduces the amount of movement horses experience. You get the picture.
Research looking at the effect of training on tendons of horses of different ages supports this. Contrary to popular belief early training whilst immature can reduce the risk of injury in the older horse, as younger tendon has a strong ability to adapt to exercise and older (mature) tendon less so. The equine digital extensor tendons do grow (hypertrophy) with sprint exercise, but not so much the flexor tendons. The SDFT and SL, with their role in elastic energy storage, do not appear to gain in collagen content or diameter with exercise once fully mature, and these tendons are mature by the time the horse reaches about two years old.
After maturity tendons get weaker with age, and so become more likely to fail at a lower strain rate. When the horse is 5 years old the SDFT has already started to degenerate, with changes in crimp angle and collagen levels causing a reduced total strength. From here on in exercise accelerates this age-related degeneration.
Some studies have shown exercise-induced increases in SDFT diameter in 2yo thoroughbreds (but not warmbloods), but not an improvement in crimp angles or biomechanical properties – in other words tendons got bigger but not stronger. Tendons can grow due to pathological changes, so in research studies an attempt is usually made to rule these out by biopsy or ultrasound (as it was in this case). Tendon can also increase in volume just due to gains in water content, which is an exercise-induced response, but not one that helps. In immature warmbloods, all tendons and ligaments adapt, improve and strengthen in response to exercise, all apart from the SDFT. In all horses the SDFT just behaves a little differently.
In elastic-energy storing tendons such as the SDFT, increased size
increases stiffness so an increase in size actually reduces function. In these tendons being able to lengthen elastically rather than snap is more important, and so too much stiffness is dangerous. The improvement in the common digital extensor tendon with exercise is more helpful in improving the performance of the SDFT as these two tendons work together to help the SDFT hit the right stiffness for elastic-energy storage from hoof strike to push off. As I covered in the last post, the introduction of scar tissue in the tendon from overuse or previous injury is another potential source of increased stiffness.
Compared to hugely-responsive tissues like bone, tendon adapts slowly to exercise, and possibly not at all once mature. It may be that research in this area just isn’t precise enough at the moment to detect changes and predict optimal training regimes. In the great hierarchy of research funding, grants are keenly fought over and some excellent projects will always go unfunded. Understanding equine tendons is not the crocodile nearest the boat for many funding bodies, and not all human research can be directly translated as equine tendons are so unique. Research continues; slowly.
Images from my own research and graphs as before from Robi et al. 2013.
When I first studied anatomy I was told that tendons had a very specific job – they attach muscle to bone, and so transmit the force of the muscle pulling to the bone, often creating movement at a joint. Ligaments, I was told, attach bone to bone and create stability at joints, holding it all together. However in horses there are some special cases where the tendons start at a bone, travel a long way and then have accessory ligaments anchoring them back to another bone; only part of the tendon is actually attached to any muscle at all. Anatomists can get very excited about which structures are tendons and which are ligaments, but we can agree that sometimes tendons have other jobs, and the muscle is just there to help adjust their tension.
Long tendons are part of what make a horse so interesting to study, and one of the ways in which the horse is specialised for locomotion. Horses don’t walk on flat feet like humans, they walk on their toenails. The muscles that control their legs are placed right at the top of the limbs, leaving the lower or distal parts to be lightweight, fast, and full of shock-absorbing joints and long tendons to store and release elastic energy. The digital flexor tendons of a horse are familiar to most horse owners because they include the most common sites of injury, as they take the brunt of impact and are predominantly stretched by the movement of the joints rather than tension in the muscles. These tendons are not there to transmit muscle pull and cause movement, they’re there to absorb motion, stretch like a rubber band as the hoof hits the ground and then ping back to length as the heel comes off, pulling the leg along with them.
In humans most tendons are short, strong and transmit force by acting like a rope. In horses’ legs these tendons are longer and more elastic. The digital flexor tendons and suspensory ligament run down the back of the horses’ legs. A sesamoid bone at the fetlock acts as a pivot and allows the tendon to transmit tension smoothly around the joint. As the hoof hits the ground, usually with enough force to break the cannon bone, the joints of the leg flex, and only the hoof feels the full brunt of the impact. The hoof travels fast and when it hits the ground it stops suddenly. Ideally the surface allows some slipping, but if the horse is wearing studs then the hoof stops very suddenly indeed. This deceleration causes an impact force. Flexing of the joint above the hoof (distal interphalangeal joint) allows the pastern bones (medial & proximal phalanx) to decelerate more slowly and flexing at the fetlock allows the cannon bone (metacarpal bone) to decelerate more slowly still, so these bones experience less impact. As the joints flex they stretch the digital flexor tendons, storing elastic energy. As soon as the heel leaves the ground the superficial digital flexor tendon can start to spring back to its shorter length, releasing this elastic energy, and helping the leg bounce along in very efficient way. Similarly the deep digital flexor tendon will recoil at toe off and return to its former length.
Except sometimes they don’t. Tendons need to be springy and elastic, but not stretch so far that they fail. One of the ways they do this is by not being straight: their collagen fibrils form a tight wave pattern – they are literally crimped. Tendon crimp means that whilst the tendon is never slack its initial bit of stretching just involves straightening out – the toe region of a length force graph. The more pronounced the crimping, the more force and stretch a tendon can take before it fails. Similarly as the horse warms up its tendons “become more able to” straighten out ready for work and are capable of sustaining larger forces and longer stretches without failure. Generally tendons are expected to work within this toe or linear region. Even within the elastic region that the tendon is capable of working in, not all the elastic energy is returned and some of it is lost as heat (hysteresis, shaded in pic). Heat build up in tendons is another major cause of damage and the reason that many old fashioned brushing boots have become unpopular.
Lesions and microtrauma in the tendon show up as imperfections in the crimp pattern, making it irregular, disturbed or with less crimp angle. These range from micro-lesions to full on blown tendons leaving big lumps of scar tissue, and as you’d imagine they all affect the tendons ability to stretch. Micro-lesions are built up by pushing the tendon to the point where individual fibres start to fail, and if not allowed to recover eventually these may cause complete failure of the tissue. The majority of catastrophic failures though require some external influence to push the length beyond the limits – such as an over-reaching hoof kicking into the tendon whilst it is already stretched.
With use tendons become stronger, more elastic, with their fibres better aligned. Basically they can withstand more before they fail. However with overuse or just plain ageing damage makes tendons weaker. The trick then, is to give a tendon plenty of training within its current elastic capabilities. Training actually affects different tendons in different ways, and responses to age-related degeneration and exercise are actually very different between for example the common digital extensor tendon and the superficial digital flexor tendon in the same leg of the same horse. Similarly there is a certain limit in how strong and elastic any given tendon will develop, based on getting the magic optimum amount of exercise in the foal. These posts sit on my desk unfinished for a long time if I try to include too much in them, so let’s stop there and cover those topics next.
Images courtesy of Jean-Marie Denoix, Ecole National Veterinaire d’Alfort, and from Robi et al., in Hamlin et al., 2013, with thanks.
