Why Is An Understanding Of Biomechanics Important?

See an article I published in Horse Magazine

Losgelassenheit - Suppleness and relaxation

For any progress to be made in building up the horses upper neck and back muscles, he must be working correctly over his back. The long back muscle must be swinging rhythmically, one side, then the other. That is, he must be losgelassen.

LOSGELASSENHEIT or suppleness  – A prerequisite for ANY work in a contact, or on straightness, impulsion or collection. Without losgelassenheit, attempting work on these things creates tension and resistance.

Only a back which has been well developed through training will be able to raise the forehand in trot. This is why the swinging back which allows the rider to sit in the medium and extended trot is the test of a well ridden horse.  If the rider is thrown up out of the saddle, this is an example of a rigidly held back that does not swing.

A section of the large rump muscles is joined to the long back muscle by a large tendinous sheet – the fascia. This means both the muscles work together during movement meaning that the hindlegs cannot stride out freely when the back is held tense. This also means that the back muscle cannot function properly if the hindlegs are restricted in their natural rhythm by the riders incorrect leg and hand aids. From the fascia also extends the broad muscle of the back, which runs from the lumbar area in an angle towards the ribs and upper arm.  If the long back muscle is held in cramped tension, this is transferred to the broad back muscle, restricting the action of the foreleg. As the long back muscle is also attached to the ribs, when it is tense it stops the horse from breathing freely. When the horse stops being tense and cramped and swings rhythmically, it can breathe and snorts. Snorting (deep exhalation) indicates a horse is relaxing.

The first thing that disrupts the function of the horses back is the incorrect seat of the rider. A rider pounding on the back in trot forces the muscle to become tense and cramped. The rider should sit lightly forward ie in the direction of the fibres of the long back muscle (These run from the top at the back to forward at the front). The back will relax even quicker is less weight is placed on it, therefore it is a good idea to begin training sessions in riding trot and only go into sitting trot when the back is supple and swinging and allows the rider to sit.

THE PRIMARY GOAL AT THE START OF ANY TRAINING SESSION IS TO ACHIEVE A SUPPLE BACK.

Exercising muscles of the back

Canter transitions, long canter sessions while out hacking, climbing hills. The canter is much more important and builds more strength than the trot.

Raising the back

Some basic anatomy

 

The horses back is a bridge between the forehand and hindquarters. It is composed of many individual bones called vertebrae. The neck has 7 cervical vertebrae, these are connected to 18 thoracic vertebrae, followed by 6 lumbar, 5 fused sacral and around 20 tail vertebrae. The sacrum is an integral part of the pelvic girdle and it is this joint (the sacroiliac joint) that the vertebral bridge receives the entire thrust from the hindquarters which gets transferred over the back as forward movement.

 

All the vertebrae have prominent spinous processes which project upwards. The spines of the front half of the back point backwards and those of the back half point forwards. The tops of the spinous processes are connected by a tendinous ligament (the supraspinous ligament which becomes the nuchal ligament as it extends from the withers to the head. This is the upper brace of the vertebral bridge. The lower brace, running from the breastbone to the pelvic girdle is made up of a mass of tendons which fuse into the central linea alba.

 

The horses back is often likened to a suspension bridge with levers at both ends. The front lever is made up of the neck (the nuchal ligament and upper neck muscles) and these do the job of pulling the backwards facing spinous processes forward and thus raising the back.

 

 At the other end, muscles of the hindlimbs and the abdominal muscles working via the sacro-iliac joint, raise the back from behind by pulling on the spinous processes of the vertebrae further back which are oriented facing forwards. 

 

 

Muscle function

MUSCLE FUNCTION

 

Muscles are the organs responsible for movement. Attached to two or more bones and extending across one or more joints, skeletal muscles are generally considered to be under conscious control. This is not strictly correct. Although a movement begins with a conscious decision, it sets off a chain of reflex reactions in associated structures that are not under conscious control.

The interlinking of parts of the anatomy mean that tension in one area is spread over a wide area (eg a tense back prevents the hindleg being able to be drawn forward fully as the long back muscle is connected to the gluteal muscle via a large sheet of connective tissue).

 

Different muscles of the body have differing amounts of tendon inlaid.

Some contain muscle fibres composed entirely of muscle cells arranged in parallel (fleshy fibres) and have little or no tendon component. These muscles are designed to contract strongly and then relax, through being stretched by antagonistic (or opposing) muscles. These muscles produce strong thrust and are primarily for forward movement. These muscles tire very quickly and build up with toxins when they are required to remain contracted (ie when they are tense). They then swell up due to poor drainage of lymphatic fluid and cannot receive sufficient nutrients. The more rhythmic the cycle of contraction and relaxation, the better the blood flow, removing waste products and reducing tiredness.

 

Other muscles have varying amounts of tendon fibre inlaid. Tendon fibres can withstand a high level of strain and muscles with a large amount of tendon inlaid can act as elastic supporting bands for long periods of time. They do the work that requires sustained even tension or stretching. They make it possible for the horse to hold itself in a raised posture and to carry the rider and balance with the riders weight.

 

One important point to realise is that a muscle cannot increase in strength (that is grow in size) if it is worked under a state of cramped tension. This tension leads to swelling and the muscle being inadequately supplied with nutrients. Instead of increasing in size, it will atrophy (become smaller).

On the other hand, muscles that work in a relaxed and rhythmic way have a good blood supply therefore receive sufficient nutrients and are able to grow larger as a result of correct work.

 

So, the first requirement for successful training in relaxation. 

Core strength and balance

 

Exercise is necessary for the horse as muscular strength is required not only for movement but effective athletic posture or carriage. Good performance is dependent on a good self carriage. In human sports, effective use of the limbs depends on a strong, stable core; therefore it makes sense that a good posture should be attained before the strength of the limbs is developed. This principle applies just as much to the training of horses.

 

The horses centre of gravity is not located halfway between its nose and its tail but, as the forehand weighs more than the hindquarters it is located more towards the front, just behind the withers.  The horse cannot change the weight of the two halves, but while running free he can alter the balance by changing the length of the neck in front of the centre of gravity or by rounding the loin and engaging the hindquarters behind it.

The horse offers correct posture as a result of balance and relaxation. The appearance of a "correct frame" can be created by force but the horse's posture will not be an honest reflection of its state of balance and relaxation.

 The horse can find its balance most efficiently when free of tension. Yet, as the horse's balance improves, tension diminishes. This is why rhythm and relaxation are the first two steps on the training scale – the very foundation on which the remainder of the work is built.

When the horse's nose is behind the vertical, the thrusting energy of the hind legs does not travel through to the poll. It only makes it to the spot in the neck where the vertebra are 'broken', at which point the energy is stifled by the heavy head and remaining neck that are hanging downward off the front. The weight of the already overburdened forehand is increased. Lifting of the forehand becomes more difficult and the imbalance creates tension, diminishing the performance.

Additionally, tension is required for the horse to keep its head behind the vertical. Either the horse must use incorrect neck muscles in order to hold the position or the rider must actively hold the horse behind the vertical. Either way, working with the face behind the vertical is an unnatural way of going for the horse that creates imbalance and tension.

When a horse has been trained to keep his head down, no matter how much he loses balance, how tricky something is or how interfering the rider is, that horse scores better in a dressage test, compared to one ridden on the fine line between collection and liberty.
That is because the horse ridden "at liberty on parole" occasionally shows his momentary loss of balance by throwing his head up. A rollkured horse has learned that opposing the rider will not improve his situation, to put it mildly.