Back (horse) - AbsoluteAstronomy.com

The back describes the area of horse anatomy where the saddle

Saddle

A saddle is a supportive structure for a rider or other load, fastened to an animal's back by a girth. The most common type is the equestrian saddle designed for a horse, but specialized saddles have been created for camels and other creatures...

goes, and in popular usage extends to include the loin or lumbar region behind the thoracic vertebrae that also is crucial to a horse's weight-carrying ability. These two sections of the vertebral column

Vertebral column

In human anatomy, the vertebral column is a column usually consisting of 24 articulating vertebrae, and 9 fused vertebrae in the sacrum and the coccyx. It is situated in the dorsal aspect of the torso, separated by intervertebral discs...

beginning at the withers, the start of the thoracic vertebrae

Thoracic vertebrae

In human anatomy, twelve thoracic vertebrae compose the middle segment of the vertebral column, between the cervical vertebrae and the lumbar vertebrae. They are intermediate in size between those of the cervical and lumbar regions; they increase in size as one proceeds down the spine, the upper...

, and extend to the last lumbar vertebra

Lumbar vertebrae

The lumbar vertebrae are the largest segments of the movable part of the vertebral column, and are characterized by the absence of the foramen transversarium within the transverse process, and by the absence of facets on the sides of the body...

. Because horses are ridden

Equestrianism

Equestrianism more often known as riding, horseback riding or horse riding refers to the skill of riding, driving, or vaulting with horses...

by humans, the strength and structure of the horse's back is critical to the animal's usefulness.

The thoracic vertebrae are the true "back" vertebral structures of the skeleton

Skeleton

The skeleton is the body part that forms the supporting structure of an organism. There are two different skeletal types: the exoskeleton, which is the stable outer shell of an organism, and the endoskeleton, which forms the support structure inside the body.In a figurative sense, skeleton can...

, providing the underlying support of the saddle, and the lumbar vertebrae of the loin provide the coupling that joins the back to the hindquarters

Horse anatomy

Equine anatomy refers to the gross and microscopic anatomy of horses and other equids, including donkeys, and zebras. While all anatomical features of equids are described in the same terms as for other animals by the International Committee on Veterinary Gross Anatomical Nomenclature in the book...

. Integral to the back structure is the ribcage, which also provides support to the horse and rider. A complex design of bone, muscle

Muscle

Muscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...

, tendons and ligament

Ligament

In anatomy, the term ligament is used to denote any of three types of structures. Most commonly, it refers to fibrous tissue that connects bones to other bones and is also known as articular ligament, articular larua, fibrous ligament, or true ligament.Ligament can also refer to:* Peritoneal...

s all work together to allow a horse to support the weight of a rider.

Anatomy of the back

The structure of the back varies from horse to horse and varies a great deal by breed, age and condition of the animal.

Skeleton

A horse has an average total of 18 thoracic vertebrae

Thoracic vertebrae

, with 5 located in the withers. Each thoracic vertebra is also associated with a rib

Rib

In vertebrate anatomy, ribs are the long curved bones which form the rib cage. In most vertebrates, ribs surround the chest, enabling the lungs to expand and thus facilitate breathing by expanding the chest cavity. They serve to protect the lungs, heart, and other internal organs of the thorax...

. A horse also has, on average, six lumbar vertebrae

Lumbar vertebrae

. Some breeds, such as the Arabian, will sometimes, but not always, have five lumbar vertebrae and 17 thoracic vertebrae. There appears to be little correlation between back length and number of vertebrae, as many horses with short backs do have the typical number of vertebrae. The length of each vertebra in the lumbar region seems to have the greater influence on the strength of the horse's back.

Muscles and ligaments

The horse has no collarbone. Hence the entire torso is attached to the shoulders by powerful muscles, tendons, and ligaments.
The spine of a horse

Horse

The horse is one of two extant subspecies of Equus ferus, or the wild horse. It is a single-hooved mammal belonging to the taxonomic family Equidae. The horse has evolved over the past 45 to 55 million years from a small multi-toed creature into the large, single-toed animal of today...

's back is supported by muscle

Muscle

s, three ligament

Ligament

s, and abdominal muscles. The Spinalis Dorsi
Spinalis
The spinalis is the portion of the erector spinae, a bundle of muscles and tendons, located nearest to the spine. It is divided into three parts.-Spinalis dorsi:...

originates on the fourth cervical vertebra

Cervical vertebrae

In vertebrates, cervical vertebrae are those vertebrae immediately inferior to the skull.Thoracic vertebrae in all mammalian species are defined as those vertebrae that also carry a pair of ribs, and lie caudal to the cervical vertebrae. Further caudally follow the lumbar vertebrae, which also...

and inserts beneath the thoracic section of the Trapezius. The Longissimus dorsi originates from the last four cervical vertebrae, and courses along the spine, inserting eventually into the ilium and sacrum. This muscle contracts the spine and also raises and supports the head and neck, and is the main muscle used for rearing, kicking, jumping, and turning. It is the longest and strongest muscle in the body, and is the muscle the rider sits on. The Intercostal muscle
Intercostal muscle
Intercostal muscles are several groups of muscles that run between the ribs, and help form and move the chest wall. The intercostal muscles are mainly involved in the mechanical aspect of breathing...

s begin at the spaces between the ribs and aid in breathing. The external and internal abdominal obliques

Abdominal external oblique muscle

The external oblique muscle is the largest and the most superficial of the three flat muscles of the lateral anterior abdomen.-Structure:...

are attached to the ribs and pelvic bones

Pelvis

In human anatomy, the pelvis is the lower part of the trunk, between the abdomen and the lower limbs .The pelvis includes several structures:...

, and support the internal organs. The Supraspinous ligament
Supraspinous ligament
The supraspinal ligament is a strong fibrous cord, which connects together the apices of the spinous processes from the seventh cervical vertebra to the sacrum; at the points of attachment to the tips of the spinous processes fibrocartilage is developed in the ligament.It is thicker and broader in...

begins at the poll and ends at the croup

Horse anatomy

(sacral vertebrae). It supports the head and neck, and its traction force aids in supporting the weaker thoracic and lumbar areas. It spreads out and attaches to the spines of the cervical vertebrae

Cervical vertebrae

. In the wither and neck area, it is called the nuchal ligament

Nuchal ligament

The paxwax or nuchal ligament is a fibrous membrane, which, in the neck, represents the supraspinal ligaments of the lower vertebræ...

Back conformation

Horses' back shape can vary greatly from horse to horse. The upper curvature of a horse's withers, back, and loin is called the "topline." The line of the belly from elbow to flank is the "under line" or "bottom line." In terms of the back, both are important; a long underine with a relatively short topline is ideal. The underline is where the abdominal muscles are, which, like in humans, can provide tremendous support to the back when well-conditioned. The topline will vary in length and in curvature, with some relationship between the two. When being ridden, a horse's back may either be stiff or relaxed as it moves, depending on the tension and strength of ligaments, muscles or tendons; and is also influenced by training and physical level of condition. The length of the back may affect smoothness of gait, ability to collect and move with agility, limits how much weight the horse can carry, and can impact if a horse might be capble of being laterally gaited

Ambling

The term amble or ambling is used to describe a number of four-beat intermediate gaits of horses. All are faster than a walk but usually slower than a canter or gallop...

. The height of the withers also varies and affects freedom of shoulder movement, length of stride, and is a major area of concern in proper saddle fitting.

A horse's back and ribcage in cross section is often described as "deep" or "narrow" (sometimes "shallow"), depending on the width of the ribs and the depth of the heartgirth. It can be a "pear" shape, an "apple" or inverted "U" shape, may be wide or narrow, short or long, or combinations of these characteristics. Wider but shorter ribs and loins will usually be stronger than long and narrow ribs and loins. If the ribs "fall off" of the back sharply, the back will be narrow, whereas if the ribs are well sprung, the back will be wide.

The average horse can carry up to approximately 25% of its body weight, but body build and, particularly, back structure, may allow it to carry somewhat more or less. Physical condition also plays a role. A horse that is in good physical condition, with well-developed abdominal and back muscles, will be able to carry more weight for a longer time than one that is not in shape.

There are two primary flaws in back conformation, a "too-straight" or "roach" back and its opposite, a too low or "sway back" (lordosis

Lordosis

Lordosis is a medical term used to describe an inward curvature of a portion of the lumbar and cervical vertebral column. Two segments of the vertebral column, namely cervical and lumbar, are normally lordotic, that is, they are set in a curve that has its convexity anteriorly and concavity...

). Horses may also have "well-sprung" ribs or be too narrow, called "slab-sided." A horse may also have very high bony withers, which is not generally a flaw, though they can make a saddle hard to fit. Too low withers, called "mutton withers," can make it difficult to keep a saddle on without rolling or slipping, and may be correlated to a shorter stride.

A roach back is less common, but is characterized by a back that has insufficient curvature. Such animals will have difficulty with flexion and are often rough-gaited. Conformational defects such as straight shoulders often are correlated with a roach back.

When the span of the back dips excessively in the center, it is called swaybacked (other names include saddle-backed, hollow-backed, low in the back, "soft" in the back, or down in the back). It is the far more common condition, particularly in older horses. A low back may make a horse more prone to a stiff head and neck carriage and usually causes stiffness in the back and difficulty collecting. A horse with a long back and loin, while often considered a trait associated with smooth gaits

Horse gait

Horse gaits are the various ways in which a horse can move, either naturally or as a result of specialized training by humans.-Classification:...

, is prone to developing a sway back sooner than average. Swayback is caused in part from a loss of muscle tone in both the back and abdominal muscles, plus a weakening and stretching of the ligaments. It is often seen in a broodmare that has had multiple foals; an older horse whose age leads to loss of muscle tone and stretched ligaments; overuse or injury to the muscles and ligaments from excess work or loads; or premature work on an immature horse. Less often, a long-backed horse that in poor condition may develop a sway at a younger age simply due to lack of exercise, particularly if kept in a stall or small pen for long periods without turnout. A sway back often makes it harder for the horse to collect, particularly for dressage

Dressage

Dressage is a competitive equestrian sport, defined by the International Equestrian Federation as "the highest expression of horse training." Competitions are held at all levels from amateur to the World Equestrian Games...

and any event that involves jumping. A sway back can also cause soreness to a horse's back because most saddles will "bridge," putting the rider's weight only on the front and the back of the saddle, creating abnormal pressure points, especially over the shoulders and loins. A heavy rider may also put additional strain on already weakened ligaments and muscles. A swaybacked horse is less able to achieve rapid impulsion; which may cause problems in such sports such as horse racing

Horse racing

Horse racing is an equestrian sport that has a long history. Archaeological records indicate that horse racing occurred in ancient Babylon, Syria, and Egypt. Both chariot and mounted horse racing were events in the ancient Greek Olympics by 648 BC...

, rodeo

Rodeo

Rodeo is a competitive sport which arose out of the working practices of cattle herding in Spain, Mexico, and later the United States, Canada, South America and Australia. It was based on the skills required of the working vaqueros and later, cowboys, in what today is the western United States,...

and polo

Polo

Polo is a team sport played on horseback in which the objective is to score goals against an opposing team. Sometimes called, "The Sport of Kings", it was highly popularized by the British. Players score by driving a small white plastic or wooden ball into the opposing team's goal using a...

. With a properly fitting saddle, a swaybacked horse still can be used as a pleasure horse and as a horse for teaching students.

Length of Back

Ideally, the length of a horse's back from the peak of the withers to the point of the hip should be 1/3 of the horse's overall body length (from the point of the shoulder to the point of the buttock, excluding head and neck). A horse's back is called "long" if the length exceeds 1/3 and "short" if less than 1/3. Long backs are more often seen in "gaited"

Ambling

The term amble or ambling is used to describe a number of four-beat intermediate gaits of horses. All are faster than a walk but usually slower than a canter or gallop...

horses, such as Saddlebreds

American Saddlebred

The American Saddlebred, formerly known as the American Saddle Horse, is a breed of horse that was developed in Kentucky by plantation owners. Today, in the horse show world, they are most commonly seen under saddle in Saddle seat style riding, and in various types of driving, including pleasure...

or Tennessee Walker

Tennessee Walker

The Tennessee Walker or Tennessee Walking Horse is a breed of riding horse. The breed was originally bred in the Southern United States to carry the owners of plantations around their lands...

s. They are sometimes, but not always, associated with long, weak loins. The advantage to a long back is that it is flexible, making the movement of the back flatter, quieter, and makes a smoother ride. Even horses that are not gaited often have a smoother trot and long strides, making them comfortable to ride. On the other hand, it makes it harder for the horse to lift or "round" the back to develop speed or engage the hindquarters for high levels of collection. It takes longer to develop the muscles in a long back, and they are more prone to muscular strain and swayback as they age.

A moderately short back is generally a desirable trait and can be seen in any breed, though are more common in American Quarter Horse

American Quarter Horse

The American Quarter Horse is an American breed of horse that excels at sprinting short distances. Its name came from its ability to outdistance other breeds of horses in races of a quarter mile or less; some individuals have been clocked at speeds up to 55 mph...

s, Arabians

Arabian horse

The Arabian or Arab horse is a breed of horse that originated on the Arabian Peninsula. With a distinctive head shape and high tail carriage, the Arabian is one of the most easily recognizable horse breeds in the world. It is also one of the oldest breeds, with archaeological evidence of horses...

, and Morgans

Morgan horse

The Morgan is one of the earliest horse breeds developed in the United States. Tracing back to the stallion Figure, later named Justin Morgan after his best-known owner, the breed excels in many disciplines, and is known for its versatility....

. The advantage to a short back is that the horse is quick, agile and strong, able to change direction with ease. A horse with this conformation is less likely to have back pain associated with the weight of the rider, especially if well-muscled. A short back is usually associated with being "short coupled," that is, short in the loin, making a horse of this conformation ideal for such agility sports as polo, roping, cutting, and reining. However, a short back can be less flexible if too short, and even ideally-conformed horses with short backs can have "springy" gaits that may cause difficulties for inexperienced riders. A too-short back can lead to spinal arthritis if the horse has difficulty bending.

Fitting saddles to the back

Each horse is different regarding saddle

Saddle

fit, though minor problems can be compensated for with saddle blanket

Saddle blanket

The terms saddle blanket, saddle pad and saddle cloth refer to blankets, pads or fabrics inserted under a saddle. These are usually used to absorb sweat, cushion the saddle, and protect the horse's back. Saddle blankets have been used for many centuries with all types of saddles...

s or pads. As a horse's muscles change with age or conditioning, one saddle may not fit during its entire life, and all saddles do not fit all horses. A properly fitted saddle should have enough height in the gullet to clear the withers of the horse and not be so wide as to press on the spine, but not be so narrow as to pinch the back and shoulders of the horse. It must not be so long in the tree that it interferes with the horse's hips, though a too-short tree may also create abnormal pressure points, particularly when it is too small for the rider as well. Professional saddlers and saddle-fitters may be able to make small adjustments in better-quality saddles to help them better fit an individual horse, but the underlying structure of the saddle tree cannot be changed and must have an adequate fit from the outset.

Causes

Back pain in a horse

Horse

may be caused for a variety of reasons. Saddle

Saddle

fit, poor riding

Equestrianism

Equestrianism more often known as riding, horseback riding or horse riding refers to the skill of riding, driving, or vaulting with horses...

technique, lack of conditioning, overwork, accidents, or lameness

Lameness (equine)

Lameness in horses and other equidae is a term used to refer to any number of conditions where the animal fails to travel in a regular and sound manner on all four feet...

can all contribute to back pain. A saddle that is not fitted properly on the horse may lead to immediate, acute pain, or chronic, long-term damage. A saddle of ill fit will repeatedly bruise, pinch, or rub the underlying soft tissue or spinal processes. A horse

Horse

that is not athletically fit may also experience back pain. Abrupt changes in work, footing, or terrain can make even a fit horse suffer soreness. Accidents, missteps, or awkward jumps all lend themselves to strain. Compensating for any type of limb, joint, or hoof

Horse hoof

A horse hoof is a structure surrounding the distal phalanx of the 3rd digit of each of the four limbs of Equus species, which is covered by complex soft tissue and keratinised structures...

injury can make a horse

Horse

put extra stress on its back, which can lead to back problems in addition to lameness if not treated promptly. A rider with a poor seat can put abnormal pressure directly on a horse's back, or may indirectly cause back pain in other ways: An ill-fitting bit

Bit (horse)

A bit is a type of horse tack used in equestrian activities, usually made of metal or a synthetic material, and is placed in the mouth of a horse or other equid and assists a rider in communicating with the animal. It rests on the bars of the mouth in an interdental region where there are no teeth...

and bridle

Bridle

A bridle is a piece of equipment used to direct a horse. As defined in the Oxford English Dictionary, the "bridle" includes both the headstall that holds a bit that goes in the mouth of a horse, and the reins that are attached to the bit....

or bad hands

Riding aids

Riding aids are the cues a rider gives to a horse to communicate what they want the animal to do. Riding aids are broken into the natural aids and the artificial aids.-Natural aids:...

, resulting in mouth pain, can cause secondary back pain as the horse lifts its neck and stresses its back to avoid the pressure to the mouth.

Diagnosis

A veterinarian or experienced horse owner can palpate the back of a horse to pinpoint sources of pain and from there assess the most likely cause. Radiographs (X-Rays) can be used to diagnose potential problems with cracked vertebrae, some forms of arthritis, impinging dorsal spinous processes (kissing spines), and other skeletal problems, although with large, heavily muscled animals this diagnostic modality is limited. Certain types of soft tissue injury can be assessed with other modern diagnostic imaging techniques, such as ultrasound

Medical ultrasonography

Diagnostic sonography is an ultrasound-based diagnostic imaging technique used for visualizing subcutaneous body structures including tendons, muscles, joints, vessels and internal organs for possible pathology or lesions...

. In addition, Scintigraphy

Scintigraphy

Scintigraphy is a form of diagnostic test used in nuclear medicine, wherein radioisotopes are taken internally, and the emitted radiation is captured by external detectors to form two-dimensional images...

is often very useful in localising either bony or soft tissue disorders.

For mild problems, it is sometimes useful to ride the horse in a different saddle or without a saddle to see if the problem goes away, but usually a veterinarian or saddle fitter can determine if an ill-fitting saddle is the problem in fairly short order. Failure to obtain a reliable veterinary opinion can lead to further damage if the horse is worked while in pain.

Treatment

Like humans, back pain in horses may be treated by acupuncture

Acupuncture

Acupuncture is a type of alternative medicine that treats patients by insertion and manipulation of solid, generally thin needles in the body....

, massage therapy

Equine Massage

Equine massage is a topic of increasing importance as a natural approach to horse care. Professional and recreational horse owners use it to improve performance, increase mobility and range of motion, and free up the horse's poll, neck, shoulders and back to improve jumping, bending, turning, and...

, chiropractic

Chiropractic

Chiropractic is a health care profession concerned with the diagnosis, treatment and prevention of disorders of the neuromusculoskeletal system and the effects of these disorders on general health. It is generally categorized as complementary and alternative medicine...

treatments, ultrasound

Ultrasound

Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Ultrasound is thus not separated from "normal" sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is...

, simple rest, or a combination of any of the above. Drug treatment may also be advised, particularly the use of NSAIDs

Non-steroidal anti-inflammatory drug

Nonsteroidal anti-inflammatory drugs, usually abbreviated to NSAIDs or NAIDs, but also referred to as nonsteroidal anti-inflammatory agents/analgesics or nonsteroidal Anti-inflammatory medicines , are drugs with analgesic and antipyretic effects and which have, in higher doses, anti-inflammatory...

, or other anti-inflammatory and analgesic

Analgesic

An analgesic is any member of the group of drugs used to relieve pain . The word analgesic derives from Greek an- and algos ....

medications. In all cases, the first step is to eliminate the root cause of pain to the horse

Horse

so that the animal is not reinjured after treatment. Degenerative or arthritic

Arthritis

Arthritis is a form of joint disorder that involves inflammation of one or more joints....

back pain is much harder to treat, so prompt attention is advisable in order to avoid a long-term problem.

If it seems the back pain is caused by an ill-fitting saddle

Saddle

, the saddle should be changed or adjusted, though as an interim measure a horse

Horse

can be ridden without a saddle

Saddle

or with a saddle pad that is either thicker or thinner, as needed to reduce saddle pressure. To avoid causing back pain caused by lack of athletic fitness, gradually build the horse's athletic agility until it is strong enough to avoid getting sore in the back. Back pain related to stress or injury may require rest and time without being ridden, with a gradual return to work.

External links

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