Good conformation is fundamentally what is anecdotally or scientifically regarded as the most efficient spread of:
- Weight
- Force
- Energy transfer
In your horse.
On the whole, the better symmetry within/between/around the horse and their legs, the less chance of injury. Less good for my job, very good for your horse 😉
In theory we want a horse that divides evenly in to 1/3rds, as this indicates an even distribution of weight carrying and weight pushing capacity, good straight joints when looking front on, but well angled shoulders, stifles and hocks when looking from the side. A well-proportioned neck and head complete the picture. In short, achieving correct proportions and conformation indicates correct and balanced distribution of weight, forces applied and movement through the horse. Keeping this in balance reduces the injury risk.
This means that there is no obvious asymmetry BETWEEN, or WITHIN limbs and landmarks of the body.
Balance front to back:
A horse naturally carries at least 60% of its weight on its forehands, and 40% through its hindquarters. One of the aims of Dressage is to encourage greater active weight carriage on the hindlimbs in order to encourage better balance, particularly for the harder movements associated with Grand Prix dressage, as well as an improved expression in the movement. In my limited experience, show jumpers also seem to require a light and nimble balance, in order to get that horse to take off over those ridiculous obstacles 😉
The forelimbs are essentially struts to carry weight, (imagine they function like a pogo stick does – bouncing again and again when you put the power through your body). The head and neck behave as a ballast which can accentuate and aid movement (this is where you start throwing your body forward on the pogo stick to move around) and energy created by the engine: the hindlimbs (your legs which act to create energy and movement in the pogo stick).
A match in power versus carrying capacity must be achievable (alongside training designed to aid this), in order for the horse to develop correctly, with good muscles. A horse that naturally achieves this will naturally find training easier compared to those who don’t.
The angle of the shoulder indicates the ease with which the forelimbs can be protracted (pulled forwards). The more sloped this angle is, the better protraction power that limb is expected to have (which means better toe flick for your dressage test, or height for your jump 😉)
Excessively long pasterns: are increasingly popular as they seem to give horses a very expressive/floaty trot. Something we all have an obsession with I imagine, however, long, thin pasterns reduce the stability with which the whole limb is balanced on…
…Imagine Jenga blocks, these represent the bones that make up the pastern and lower limb: your tower gets taller and thinner as you remove blocks and it loses stability. Putting your hand at the top of them helps to stabilise the tower. That act of compressing the blocks creates stability. That same compression can be mimicked by the tendons… These can actively contract and tighten the Jenga blocks (or distal limb bones) together, creating stability. However, this means you increase the tension in tendons before you’ve even asked for increased workload.
Increased tendon tension = increased risk of injury = increased risk of breakdown, tears, vet bills and “WHY DO I DO IT” (note: author’s personal experience) 😉
So: Short, wide pasterns provide a good sturdy base for the horse’s large weight, plus you, plus the movements you are demanding.
Balance between limbs:
Left to right balance encourages symmetry under saddle and reduced likelihood of one being overloaded (and increased risk of injury). Mechanical abnormalities can be mistaken for lameness, which is where experience and understanding biomechanics is crucial to understanding your horse (and trusting practitioners working with your horse!). Increased load on one limb increases the load and strain more than its natural capacity can handle. This can also create training problems (those days when you feel like rigor mortis has set in on one side of your horse sounding familiar?), and injuries, because increased strain does that to living tissues.
Balance within limbs is just as crucial:
Even spread of weight and pressure thanks to a symmetrical joint means balanced strain on the tendons and ligaments surrounding that joint capsule, and reduced risk of damage and injury to all these structures. If however the joint between two bones is asymmetrical, that difference can create increased compression on one side of the joint, and reduced pressure on the other. This results in greater risk of arthritis and greater strain on tendons, because they can be stretched asymmetrically and have to work harder to compensate for this pattern.
Science buffs: An experiment was designed to test this – wedges were placed at the side of hooves (to force asymmetry on joints), and joint mechanics were recorded. Reduced joint flexion was observed as a result: Meaning that tendons and ligaments intervened and actively compensated for the new force being applied. This was to reduce the asymmetrical force applied to the limb, and reduce the abnormal movement which would result, and which would increase risk of injury and pain. This increased tendon strain however… that was likely to damage it long term. Many studies have tested different elements of this to determine similar conclusions: tendons will actively compensate for asymmetry and asymmetrical forces applied, and this definitely exacerbates their risk of damage and deterioration.
Straight hocks and stifles: indicate poorer shock absorption, and poorer movement efficiency generated by the hindlimbs. With the amount of power generated in the hindlimb, poor angles (aka straight limbs) means less efficient and effective shock absorption, and a higher likelihood of arthritis. Higher chances of arthritis in the hocks indicates increased pressure on the backs, particular the lumbar back region, and can cause secondary problems with stifles (as mentioned previously with either over-active or underactive quadriceps muscles) and eventually hindlimb tendon pathologies/problems. In summary: Not good.
Long backs often create a lovely softer ride, and these horses seem to develop a lovely rhythm (albeit a slow one commonly). However this long back can mean increased strain on the stifles, as they compensate for an unnaturally long wheel base, and the horse finds it harder to push underneath and carry weight behind. Stifle inflammation is likely to occur as a result of overworked quadriceps muscles, or inefficient function of Quadriceps. (Pokemon is a prime example of quite a long back, and I was forever teaching him to sit and weight, strengthening his back and encouraging him to lift his front end.) The lumbar back region is the point of transfer of power from the hind end, along the back to propel the forelimbs forwards. If this is excessively long, instability can occur, resulting in pain and compensations. Furthermore, this part of the back is not supported by a rib cage, and is therefore responsible for supporting a portion of the abdominal cavity “unaided” so to speak. Increased weight and/or increased back length will make this function far more difficult.
It can be hard to spot asymmetries, particularly if you’re not trained to do so. Horse hooves can highlight red flags both in terms of confirmation, and movement. Next weeks post will be heavily focussed on hooves. As a precursor, “no hoof no horse” is a common mantra in the horse world, and yet I have only in the last week truly understood and experienced quite how much a difference that can make.