Most people involved with horse training would be aware of the basic skeletal structure of the horse. As a quick recap of some aspects that are important for this article: the horse has a leg in each corner, 2 front legs and 2 back legs. The backlegs are connected to the trunk via a true joint, so there is a boney connection between back legs and the vertebral column and pelvis. This is important for the propagation of forward and upward pushing & carrying power during the horse’s locomotion and when carrying a rider.
The front legs, however, are NOT connected via any joints, since the horse - unlike people - does not have a clavicle bone (or 2 in fact, one on the left of the sternum and one on the right of the sternum, in people).
Why is that, you might ask? This is a really good question. Given that nature is rather clever and usually does not put things into place for no reason - or, as in this case - leaves something out for no good reason. But this is a topic for another article.
So for now, let’s just consider what is there instead of a bony/joint connection.
What structures take over the function of holding the front legs to the side of the chest and ribcage?
These structures are mainly muscles with their tendons and fascia and the situation is much like that of a cradle. The chest, or thorax can “swing”, rock, lift and fall, just like a cradle, relative to the position of the shoulder blades and the front legs
This interesting arrangement enables the horse to literally lift itself up by its “boot straps” or better, by its muscles around the chest and shoulder blades and grow some inches. We have all seen it, when your horse gets excited and suddenly appears a hand taller - well, that is what actually happens. Maybe not a whole hand, but easily an inch, and that has been shown in various studies.
Conversely, it can also sink “in between the shoulder blades”, so the muscles and connective tissue structures relax and the chest sinks closer to the ground relative to the shoulder blades. Suddenly your horse appears not to have much of a wither at all and looks like it has “shrunk” in size.
For riding and training purposes, this ability of raising the chest relative to the shoulder blades is vitally important. Not just because as a dressage rider and/or general trainer you want your horse to “come out of the withers” and “grow in front” (this is a true sweet spot when you get this feeling in your training and it feels like sitting on a cloud), but more importantly, being able to do this is important for the horse’s health and ongoing soundness. In fact, it is SO IMPORTANT, that any horse training under saddle for any discipline should seek for this to happen to safeguard the horses front legs for future soundness. Not paying attention to this is equal to asking a totally unfit person to run a marathon and lift ridiculously heavy weights and then wonder why their bodies break down and they end up with tendon and ligaments strains and muscle tears.
So let’s explore why that is and what has to happen for this lifting to occur - this is where one muscle comes into focus, the serrate muscle (or more precisely, the ventral serrate muscle because there is also a dorsal serrate muscle, but that is not important for our discussion here).
Firstly, where is it located and what can it do?
This muscle has 2 parts, one is located on the trunk ( serratus ventralis thoracis), behind the shoulder blade. The other part is located at the side and base of the neck (serratus ventralis cervicis).
The thoracic part originates on the side of the first 8 to 9 ribs and run to the inside (or underside) of the shoulder blade. Together they form an elastic support to help suspend the chest in between the front limbs. If one side acts by its own, it either pulls that limb closer to the chest or brings the chest (and thereby the horse’s weight) further over the limb on that side.
This muscle if often very tendinous on its surface (ie it has a lot of tendon fibres/ie fascia) and is linked via that same fascia tissue to the external oblique muscle.
Picture created with Biosphera.org
What does that mean, if a muscle has high proportion of tendinous tissue? Any muscle that has a high proportion of fascia/tendon tissue it means that when the muscle relaxes (this is done via the muscle tissue only), it still helps to suspend the horses chest (ie weight) in between the front limbs even if the actual “muscle” relaxes. It also indicates that muscles like this have an important function not just in locomotion but in functional & positional stability. I am putting this bit of information out here, because there are other muscles like that in the horses body.
The cervical portion originates on the transverse processes of the last 4-5 neck vertebrae and also inserts on the inside of the shoulder blade.
The two portions when acting together help to LIFT the chest in between the shoulder blades. When they do not act together, they work antagonistically (in opposite way), the cervical portion draws the forelimb forwards and the thoracic portion draws the limb backwards, facilitating the swing of the limb.
How does this relate to correct horse training?
This muscle is likely the most important muscle that we need to target in the early training of a young horse or likewise in the retraining of a horse in rehabilitation after injury or a horse that has been out of work for any length of time for other reasons. This also should include mares that have been out on pasture used as broodmares and brought back into training.
Biomechanically, it is the most important muscle acting like a buffer or shock-absorber for the weight of the horses trunk into its legs. So it becomes obvious, that if untrained, it will be weak and most of the weight will go straight down into the horse’s front legs. The next structure, or the lowest structure that is designed to take on this weight is the “suspensory apparatus”. I say “apparatus” because it is a group of structures on the back of the horse’s lower leg, which includes the suspensory ligament.
When the horse only has to balance and carry itself, this kind of weight is usually not an issue. The problem starts when we ask the horse to do things nature has not intended it to do: this includes working in circles a lot with the expected round way of turning and obviously being ridden, let alone jumping.
If you ride your horse without conditioning this muscle PRIOR to riding, you overwhelm the shock absorbing ability and all the weight will go down into the suspensory area and the joints of the lower limb - often leading to microtrauma and later on the potential for tendon and ligament failure.
One other aspect of the function of this muscle is that by acting as a shock absorber it has a certain amount of “bouncing” activity. This is not just a cute little detail but gives us valuable clues as to the way to train and condition this muscle.
IF we create a certain amount of “bounce” without over taxing the tissue, it will lead to strengthening of this muscle and thereby increased upward support ie the muscle is more able to hold the chest up in between the shoulder blades. This is what we want to achieve with our training. If you practice yoga, think “cat” where you are pushing your chest toward your shoulder blades to stand as far away from the ground as possible in a kneeling position and not have your weight jam into your wrists.
The best way to gradually train and strengthen the “bounce” is by trotting in working trot. Incidentally, the working trot is THE classical gait for early/ remount training. And now we have one of the biomechanic reasons why this has been done and considered important for many decades.
The walk, whilst equally important in the horses training, is far less suitable for this specific purpose, so is used for other reasons (maybe in another article)
So what about the canter? The canter can also be utilized but only after a few weeks or months of initial strengthening in the trot. The reason being that the muscle has to have some initial strength already in order to support the full weight especially during the phase of the canter stride which only is supported by one front leg. If the muscle is insufficiently conditioned and you canter too much too early, you force an enormous amount of weight into one front leg which leads to early damage of some of the above mentioned structures and will shorten the athletic lifespan of your horse.
Use the canter sparingly and later on, you can canter more because by then it will be beneficial, specially for the higher phase of the shock absorber action of this muscle, which is the posture that your horse will need to achieve during an active forward canter jump to carry its trunk forwards and upwards toward the rider’s hands. But again, this is not something you can expect the horse to do safely in the early stages of its training.
I have a young horse (or an unconditioned horse), its been backed and what do I do now? Do I put the saddle on, hop on and start trotting?
Well, yes and no! You should first lunge you horse in a specific position to do the very initial pre-riding conditioning work that helps the horse to find its new balance (on a circle) and train its correct posture WITHOUT the rider. When that is well established - and this period could last for 3+ months), then you can start riding. The riding has to be done in exactly the same posture as you have practiced on the lunge. So with a green broke horse, you should still hop on and ride, but only for a very short period (5-10 minutes max) and possibly only in walk. More to ensure the horse is still happy to be ridden and you can do some early balancing work to keep it going straight. The majority of the postural, muscle conditioning work is done on the lunge.
Again, this is what was done in classical training by the old Masters who knew from experience what to do to train a horse for soundness and longevity.
And as a final comment: the reason why training this way might take more time initially is due to the fact that we are training not for muscle power strength but for postural stability. This training involves and targets those muscles that have a higher proportion of fascia (tendinous tissue). As most of you might appreciate from possibly having had to wait for a tendon or ligament injury to heal, this tissue takes a longer time to adapt. Hence your training has to be short and often and for a longer time period. Remember, the actual training, the period of time that you work the horse, is just the “stimulus” for the tissue, putting it under stress for a short time. The “rest” period after the work is the time the body will use to adapt the tissue to the new demands. That is the time when actual adaptation happens. So it is important to understand that any training should never be so long that the horse gets tired. Fatigue is the enemy of healthy tissues, and it is during times of fatigue that tissue will fail and injure.
We will talk about this position and how to establish a correct “working trot” for each horse in the next article.
Coming up: Train for future soundness Part 2: Aspects of correct lunging and early work under saddle
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