Sacroiliac Pain In The Horse
by Erin Hackney, CEMT
Sacroiliac pain is a common occurence in horses and can be a primary or secondary source of pain causing acute or chronic lameness. The affected area is the sacroiliac joint of the horse's lower back/pelvis, and its surrounding structures. Human use of the horse in sport has contributed in a large way to horses developing this type of pain.
Studies have shown that sacroiliac injury must be considered when investigating any suspected back injury in horses. A University of Minnesota study cited sacroiliac-related problems as the cause of pain in over 50% of horses admitted to their clinic with suspected back injuries over a 5 year period, while researchers at the University of California, upon post-mortem examination of the spines of Thoroughbred racehorses euthanized for unrelated reasons, determined that all of these showed acute injury or degenerative/arthritic changes in their sacroiliac joints (Myhorse.com). In the UK, dressage and jumping horses were reported to be at high risk for sacroiliac region pain by the Animal Health Trust (Myhorse.com), after a 5 year study revealed sacroiliac disease in 74 horses - of which 73 had sacroiliac abnormalities confirmed by nuclear scintigraphy (Dyson and Murray, 2004). Despite these studies into sacroiliac disease in the horse, much is still unknown and diagnosis remains difficult .
The Sacro-Iliac joint connects the sacrum to the pelvis at the ilium. The lumbo-sacral joint is a hinge joint located between the last lumbar and the first sacral vertebrae. It is is the highest joint of the horse's hind limb, and is responsible for determining the amount of power produced by a horse's hind end during movement. The hindquarters of the horse in motion operate under two basic principles: firstly, whatever the stifle does, the hock must do. If the stifle folds, the hock must fold, and if the stifle opens, the hock must open. Secondly, whatever the loins do, the stifle must do. If the loins coil, the stifle must fold, and if the loins flatten, the stifle must open. (Bennet, 1991). Engagement of the hindquarters involves the coxo-femoral joint and, more importantly, the lumbo-sacral joint. The sacro-iliac joint acts as an anchor point, supporting the motion of the lumbosacral joint, and aiding in the stability of the hind end. Little movement occurs at the sacroiliac joint. This area has two sets of ligaments, either of which can become sprained or strained, causing pain to a horse: the dorsal sacroiliac ligaments run from the tuber sacralae (point of hip) to the top of the sacrum, helping to anchor the illium to the sacral spine; the ventral sacroiliac ligaments are located deeper, in the area of the sacroiliac joint itself, and are mainly for stablization of the joint. Additional problems affecting the sacroiliac region may include arthritis, fractures of the iliac wings, and subluxations, although these are considered rare (Myhorse.com). Absence of discs, an indication of ankylosis (stiffness/fixation of a joint by disease) was a common abnormal finding in horses studied by Jean-Marie Denoix, DVM, PhD at the Centre d'Imagerie et de Recherche sur les Affections Locomotrices Equines (CIRALE).
Symptoms of sacroilliac pain can include any or several of the following: asymmetry of the hindquarters, a "hunter's bump" or a tilted pelvis; poor performance, especially at slower paces; intermittent and marked hind limb lameness, stiffness and rigidity of the spine; dragging of one or both toes of the hind leg with a tendency to "plait", a slight dropping of the affected quarter; lack of impulsion from the quarters (Jeffcott, 1998). A horse may obviously favour one lead or frequently cross-canter, have difficulty with cavaletti, be difficult to collect, refuse jumps, jump long, and have difficulty with bascule over fences. There may be uneven muscling, a knocked-down hip, pain on palpation of the area of the tuber sacralae (hip area), sensitivity to palpation of the lower back and sacrum, pain when the leg is pulled back and/or forward. (MyHorse.com); sinking away from the saddle when rider mounts, when saddle is placed on the horse's back, or when the girth is tightened; resistance to forward movement; refusal to jump/break from the starting gate; vigorous tail movements or grinding of the teeth (Sellnow, 2002).
Diagnosis of sacroiliac pain is difficult, for a number of reasons. Back pain in horses is usually considered a secondary, symptomatic issue caused by the horse compensating for injury in a limb - while sacroiliac injury can be a primary source of pain. Because of the location of the sacroiliac joint, underneath layers of heavy muscle, it is difficult to view and assess the extent or even the type of injury that may be present. In order for radiographs to be taken, a horse must be positioned laying on its back, and anaesthetic will most likely be required which can place a horse at risk of injury while returning to consciousness. In addition, if it is a soft tissue injury, radiography will be ineffective and is mostly indicated in the event a fracture is suspected. Nuclear scintigraphy (bone scan)is relatively accurate for determining the presence of sacroiliac problems, however it cannot pinpoint which structures (ligament, joint or bone) are affected, and is expensive for the owner. Diagnostic ultrasound is a more effective way of determining abnormalities in this area; soft tissue damage and asymmetries can be found by viewing the joint with an ultrasound probe in the rectum.
Some horses may be conformationally pre-disposed to developing sacro-iliac conditions. Large-framed horses with long lumbar spans and weak quarters tend to be more at risk. Some horses may suffer a traumatic event, such as a fall backwards, which may cause injury to the hindquarters and sacroiliac pain.
Human use and management can also play a significant role in the development of sacroiliac disease. The horse's musculoskeletal system was designed to cover ground efficiently and to quickly escape predators when required (Anderson). Under natural conditions, horses would sometimes spend hours moving from one source of water to the next, often at a trot. The back displays very little movement during trotting, making this a very efficient, sustainable gait for travelling over long distances (Anderson) while during a canter, the back shows much more flexion and the horse is enabled to quickly sprint away from danger - but this gait is best suited to short, "emergency" situations and not intended to be sustained by the horse for extended periods of time. The horse's back is the "true source of motion, equilibrium, and co-ordination" (Denoix, 1997). The hind limbs of the horse are often compared to the engine of a car, and the horse's sacroiliac joint is considered the transmission. Contractions of the pairs of antagonist muscles in this area produce protraction and propulsion of the horse's hind limbs. Movement is transferred forward down the horse's back, the thoracic and cervical spine aiding the horse in keeping its balance.
Human use of the horse for pleasure or competitive purposes counters the horse's evolutionary design in that horses must perform work at the canter often, and for longer durations, than a horse would naturally. During a course of jumps or a dressage test, a horse must canter for often lengthy periods of time, performing repetitive movements which it would never perform under natural conditions, such as lengthy periods of collected work, or the act of clearing jump after jump in succession -- all while balancing the weight of a rider on its back. Horse sports today are designed to challenge both horse and rider, and horses are often pushed beyond their physical limits, leaving them vulnerable to injury and disease.
This problem is worsened if an animal is not properly conditioned to perform the work being asked of it. In his book, Physical Therapy and Massage for the Horse, Jean-Marie Denoix points out that "the weight of the rider hinders lumbo-sacral flexion". A rider on the horse's back adds weight and exerts a downward force on the muscles of the horse's back, which yield away from this pressure, becoming tense and rigid. If a rider is tense, this emotional energy is transferred to the horse, and if ill-fitting tack is used, pain is amplified. An uneven rider can put uneven weight on a horse's spine, and an uneducated rider may use many mechanical aids excessively or incorrectly , in many cases causing undue pain and suffering to the horse. Devices which force a horse's head down, such as tie-downs, martingales, side reins adjusted too tightly, draw reins used too often or by inexperienced riders, and certain controversial training techniques such as "rolkur" in dressage, are all factors which can negatively affect a horse's well-being and may contribute to an animal developing sacroiliac injury. In the horse, as in the human, "emotional and psychomotor problems reveal themselves in the back"(Denoix, 1997). A sore, tense or fatigued horse has rigid movement, often with its head thrust skywards and its back stiff and "hollow". Vertebral pathologies are the result of continuation of these conditions, and in order to avoid further damage to the spine, careful preventative measures should be employed.
When selecting a horse, conformation should be analyzed to determine if a mount is suitable for the task it will be asked to perform. Form must suit function: an animal with a short back relative to its total body length, and short lumbo-sacral span is able to coil its loins with greater ease than one who has a long back and a lumbo-sacral span measuring in excess of 4 inches (to determine lumbo-sacral span, one must locate on the horse, the lumbo-sacral space - this can be felt as a small "dip" just before the highest point of a horse's croup. Using a piece of string or even simply drawing a line across the top of the rump with a finger from hip to hip, a triangle can be formed from hip to hip, hip to LS joint and from LS joint to the other hip. The distance from the LS joint to the midline of the triangle is the lumbosacral span. Ideally, this space should be less than 4 inches, and for a well-coupled animal capable of much athleticism, it can be around 1-2 inches or less.) This type of animal is more suited to performing the advanced level collected movements required during competition such as dressage and showjumping, and is likely to be much more athletic in general.
When a horse's hind end is correctly engaged (in dressage terms, when he is working "through"), his abdominal muscles are held tight, and his longissimus dorsi muscle is flexed upward, supported by the iliopsoas muscle running from the pelvis under the spine. His neck is arched, and the so-called "chain of muscles" is at work. He is better able to support the weight of a rider, provides a more comfortable gait for the rider to sit, and is less likely to suffer pain or injury as a result. Conversely, if a horse is unable to flex at his lumbo-sacral joint due to the way he is put together, he is unable to engage the ventral chain, and his abdominal and back muscles are likely to suffer.
A horse with a long lumbo-sacral span may be more comfortable for the novice rider, as its gaits will be flatter and therefore easier to sit for a rider with an inexperienced seat; however, this type of horse will have trouble with any exercises where it must collect itself such as rollback turns, advanced dressage movements, barrel racing, quick stops and turns, going down steep hills, etc. Horses with long lumbo-sacral spans tend to jump longer and flatter, and for this reason may be favoured in the entry levels of the hunter show ring. Different breeds have developed with different requirements for back lengths, although there are always variations within a breed. For example, the standardbred horse, bred for trotting or pacing distances of 1 mile in under 2:00, tends to have a long back and long lumbosacral spans are frequently seen also. Some of the fastest horses have had this sort of conformation, which has influenced most of the horses we see racing today. The standardbred was developed to cover flat racetrack surfaces efficiently at high speed, and races are contested over oval-shaped tracks with two long straight-aways and two gradual turns. A horse with a longer back may have a greater stride length, and so will cover more ground, which can pay off in a flat race. Many of these animals show very little lateral flexibility, and many are not capable of much vertical flexion in their hindquarters compared with their warmblood counterparts, but for their intended purpose, these traits are not always necessary. While it is not impossible to condition a Standardbred to perform efficiently under saddle when its racing days are over, it may take a longer time and very likely a lot more effort on the part of the rider, especially in the initial stages. Many off-track standardbreds tend to excel at endurance riding, trail riding and as school horses due to their excellent temperaments and tough competitive natures. The level to which a member of this breed may rise in competitive circles may hit a plateau at some point, simply due to the fact that the intended purpose for which a Standardbred was designed is different than that of an animal bred specifically for jumping or dressage, but there are always exceptions to the rule, and while particularly well-coupled Standardbreds do exist, they are perhaps not often favoured by trainers looking to race on the flat.
In summary, if looking to avoid sacroiliac pain, one should avoid horses with excessively long backs and weak-looking hind ends as this type of conformation will put excess stress on the underlying tissues and joints, eventually leading to injury. For competitive purposes, riders should select horses with the best conformation for their sport that their pocketbook will allow, and attention must be paid in particular to hind end conformation, as this is the source of the horse's power. There are no guarantees, and no perfect horses, but conformation assessment prior to purchase can be key to preventing sacroiliac pain.
Proper saddle fit is very important to preventing pain in the horse's back, but is not recognized as a primary cause contributing to sacroiliac dysfunction as the structures involved in sacroiliac disease are mainly located further back than the area on which a saddle sits. A poorly fitting saddle is more likely to produce secondary sacroiliac pain, as soreness in the longissimus muscles supporting the spine may refer pain to the sacroilliac area.
A proper warm-up and cooling out period are essential in the prevention of equine back injuries. Most riders would agree that a warm-up period under saddle is a necessary and important part of a horse's fitness program, but many may not consider that the muscles of a horse's back and hind end should be warmed up and stretched prior to weight being placed upon them; this can be an important preventative maintenance technique. For prevention of sacroiliac pain, a rider should pay particular importance to stretching the hind legs, back and hip area in order to maintain suppleness of the soft tissue in this area. Once a rider has mounted, active stretching exercises may be practiced to increase strength and suppleness and to ease an animal into more advanced movements. When muscles work, they become shortened. To maintain flexibility, they must be stretched to their original, pre-workout length. A sufficient cool-down period of walking, either mounted or in-hand, and post-workout stretching helps a horse to maintain suppleness and reduces lactic acid buildup in the muscles which speeds up a horse's recovery time. Cold muscles should never be stretched, as this can cause injury: but turning a horse out prior to work, or handwalking/light lunging prior to performing passive stretching exercises such as belly lifts to warm up the horses' back prior to exercise, may lessen the chance of injury to a horse's back and sacroiliac area by helping to maintain muscular tone and flexibility. A rider must constantly observe and get to know what is normal for each individual horse, and know when a horse has reached its limits. This is vitally important to preventing injury. A rider must know when to stop pushing an animal.
Equine massage therapy, physiotherapy, and many other forms of bodywork are useful tools for a rider to employ in order to prevent sacroiliac injury. A trained equine massage therapist or bodyworker with a good knowledge of equine anatomy uses touch to detect heat, pain, tension, tenderness, or even energy imbalances over a horse's back. Being aware of a problem is the first step to correcting it. Getting to know what is normal for each horse's back will allow a rider to recognize the first signs of trouble and take steps toward correcting a small problem before it develops into a major issue.
Working a horse properly may be the most important step in preventing sacroiliac pain. A horses' muscles work in opposing pairs to produce movement, and all locomotor muscles are connected in what is sometimes called the "chain of muscles". It is very important for these muscles to be allowed to strengthen and develop gradually, as well as symetrically, and from several angles. Too much work in one direction, such as always working a horse to the left, can cause uneven muscle development, eventually leading to strain and injury. The adductor and abductor muscles of the horse must be developed through use of lateral exercises incorporated into the training programme. Strenghtening the abdominal muscles of the horse can help to strengthen the lower back muscles which support the spine and the sacroiliac area. A few useful exercises to help prevent sacroiliac pain in horses include: riding on hills (increase of speed uphill/decrease of speed downhill); work over poles on the ground or raised slightly above; gymnastic exercises and cavaletti; backing up (reinback).
Treatment options for sacroliiac pain in the horse are limited, can be expensive, and are of varying effectiveness. Injections into the sacroiliac joint have been attempted with varying rates of success - possibly due to lack of adequate diagnosis. Many people inject SI joints to avoid the cost of diagnosis, as it can be less expensive to inject than to undergo a nuclear scan or rectal ultrasound.
Acupuncture is a treatment option which has proven to be successful for many horses. Chiropractic techniques are another area which may be of some benefit, again depending upon the root cause of the pain. In order to resolve a sacroiliac issue, treatment must be practiced in conjunction with a careful physical and lameness examination(Sellnow, 2002) and the training program of the horse must be brought under review as well.
In Canada at present, both acupuncture and chiropractic treatments for horses must be practiced by a licensed veterinarian or human chiropractor, while body work, energy healing, and massage therapy are currently unregulated by any governing body. In this regard, horse owners must choose carefully a practitioner of so-called "alternative" therapies, in order to avoid further injury and to allow their animals a greater chance of recovery.
For minor sacroiliac pain, there are many hydrotherapy techniques which can be used relatively safely, again with varying results. Magnetic therapy (using magnetic blankets over the horse's back) may help to maintain a horse with chronic sacroiliac pain. Magnets are said to increase circulation to an area, thus relieving pain, and may be most effective in cases of pain due to arthritis/bone issues. The effectiveness of magnetic therapy lack significant scientific proof, and much of the support for it has been anecdotal. Applying poultices or ice to the back in the case of acute injury, or sweating the back by applying liniments and a plastic bag are other techniques of varying effectiveness which may be reccommended by a veterinarian/alternative practitioner in treating sacroiliac pain.
Complete stall rest may be recommended for some horses, for instance in the case of ligamentous damage, etc. Alternatively, a program of physical rehabilitation/therapy may be reccommended, in the case of chronic pain or pain caused by arthritis, etc. It may be helpful to look at a horse's diet to determine if there are nutrients lacking which may aid in the formation of certain tissues or in proper bone/cartilage formation of the horse. This is why proper diagnosis is so important in the case of sacroiliac pain, and also why it is such a difficult problem to treat.
Due to the nature of sacroiliac pain in the horse, it is much easier to prevent injury in the first place, through careful selection of animals and proper management of a horse's fitness routine, than to treat an animal once injured. Riders should do as much as possible to educate themselves on conditioning animals for their chosen sport, and should do everything in their power to ensure that animals are not pushed beyond their fitness levels in order to maintain sacroiliac and overall soundness for as long as possible.
References
Back Pain and the Sacroiliac Joint in Horses, author and date unknown, MyHorse.com featured article,
http://www.myhorse.com/back-pain-and-sacroiliac-joint-horses.html
Pain associated with the sacroiliac joint region: a clinical study of 74 horses. Dyson, S. and Murray, R. Equine Vet J. 2003 May;35(3):240-5. From: PubMed.gov http://www.ncbi.nlm.nih.gov/pubmed/12755425?dopt=Abstract
Pain Associated with the Sacroiliac Joint Region: A Diagnostic Challenge, S.J. Dyson, in: In: 50th Annual Convention of the American Association of Equine Practitioners, 2004 - Denver, CO, USA, (Ed.). Publisher: American Association of Equine Practitioners, Lexington KY. Internet Publisher: International Veterinary Information Service, Ithaca NY (www.ivis.org), Last updated: 4-Dec-2004; P1463.1204 found at: http://www.igloo.lv/horses/harm/sacroiliac.html
Principles of Conformation Analysis, Volume III. Deb Bennett, PhD. 1991. Gaithersburg, MD: Fleet Street Publishing Corporation.
Physical Therapy and Massage for the Horse. Jean-Marie Denoix & Jean-Pierre Pailloux. 1997. North Pomfret, Vermont: Trafalgar Square Publishing.
Equine Back Problems. Leo Jeffcott, BVetMed, PhD, FRCVS, DVSc, MA, DSc. The Horse.com - May 01 1998, Article #491. http://www.thehorse.com/Print.aspx?ID=491
The Equine Spine -- Back To Work. Stephanie L. Church, Editor-in-Chief. The Horse.com - March 1, 2001 Article #59. http://www.thehorse.com/Print.aspx?ID=59
Your Horse's Back. Kathy Anderson, PhD. From Equus Magazine online. http://www.equisearch.com/horses_care/health/anatomy/horse_back_112009/2
Stretch Exercises for your Horse: The path to perfect suppleness. Karin Blignault. 2003. London: J.A. Allen.
by Erin Hackney, CEMT
Sacroiliac pain is a common occurence in horses and can be a primary or secondary source of pain causing acute or chronic lameness. The affected area is the sacroiliac joint of the horse's lower back/pelvis, and its surrounding structures. Human use of the horse in sport has contributed in a large way to horses developing this type of pain.
Studies have shown that sacroiliac injury must be considered when investigating any suspected back injury in horses. A University of Minnesota study cited sacroiliac-related problems as the cause of pain in over 50% of horses admitted to their clinic with suspected back injuries over a 5 year period, while researchers at the University of California, upon post-mortem examination of the spines of Thoroughbred racehorses euthanized for unrelated reasons, determined that all of these showed acute injury or degenerative/arthritic changes in their sacroiliac joints (Myhorse.com). In the UK, dressage and jumping horses were reported to be at high risk for sacroiliac region pain by the Animal Health Trust (Myhorse.com), after a 5 year study revealed sacroiliac disease in 74 horses - of which 73 had sacroiliac abnormalities confirmed by nuclear scintigraphy (Dyson and Murray, 2004). Despite these studies into sacroiliac disease in the horse, much is still unknown and diagnosis remains difficult .
The Sacro-Iliac joint connects the sacrum to the pelvis at the ilium. The lumbo-sacral joint is a hinge joint located between the last lumbar and the first sacral vertebrae. It is is the highest joint of the horse's hind limb, and is responsible for determining the amount of power produced by a horse's hind end during movement. The hindquarters of the horse in motion operate under two basic principles: firstly, whatever the stifle does, the hock must do. If the stifle folds, the hock must fold, and if the stifle opens, the hock must open. Secondly, whatever the loins do, the stifle must do. If the loins coil, the stifle must fold, and if the loins flatten, the stifle must open. (Bennet, 1991). Engagement of the hindquarters involves the coxo-femoral joint and, more importantly, the lumbo-sacral joint. The sacro-iliac joint acts as an anchor point, supporting the motion of the lumbosacral joint, and aiding in the stability of the hind end. Little movement occurs at the sacroiliac joint. This area has two sets of ligaments, either of which can become sprained or strained, causing pain to a horse: the dorsal sacroiliac ligaments run from the tuber sacralae (point of hip) to the top of the sacrum, helping to anchor the illium to the sacral spine; the ventral sacroiliac ligaments are located deeper, in the area of the sacroiliac joint itself, and are mainly for stablization of the joint. Additional problems affecting the sacroiliac region may include arthritis, fractures of the iliac wings, and subluxations, although these are considered rare (Myhorse.com). Absence of discs, an indication of ankylosis (stiffness/fixation of a joint by disease) was a common abnormal finding in horses studied by Jean-Marie Denoix, DVM, PhD at the Centre d'Imagerie et de Recherche sur les Affections Locomotrices Equines (CIRALE).
Symptoms of sacroilliac pain can include any or several of the following: asymmetry of the hindquarters, a "hunter's bump" or a tilted pelvis; poor performance, especially at slower paces; intermittent and marked hind limb lameness, stiffness and rigidity of the spine; dragging of one or both toes of the hind leg with a tendency to "plait", a slight dropping of the affected quarter; lack of impulsion from the quarters (Jeffcott, 1998). A horse may obviously favour one lead or frequently cross-canter, have difficulty with cavaletti, be difficult to collect, refuse jumps, jump long, and have difficulty with bascule over fences. There may be uneven muscling, a knocked-down hip, pain on palpation of the area of the tuber sacralae (hip area), sensitivity to palpation of the lower back and sacrum, pain when the leg is pulled back and/or forward. (MyHorse.com); sinking away from the saddle when rider mounts, when saddle is placed on the horse's back, or when the girth is tightened; resistance to forward movement; refusal to jump/break from the starting gate; vigorous tail movements or grinding of the teeth (Sellnow, 2002).
Diagnosis of sacroiliac pain is difficult, for a number of reasons. Back pain in horses is usually considered a secondary, symptomatic issue caused by the horse compensating for injury in a limb - while sacroiliac injury can be a primary source of pain. Because of the location of the sacroiliac joint, underneath layers of heavy muscle, it is difficult to view and assess the extent or even the type of injury that may be present. In order for radiographs to be taken, a horse must be positioned laying on its back, and anaesthetic will most likely be required which can place a horse at risk of injury while returning to consciousness. In addition, if it is a soft tissue injury, radiography will be ineffective and is mostly indicated in the event a fracture is suspected. Nuclear scintigraphy (bone scan)is relatively accurate for determining the presence of sacroiliac problems, however it cannot pinpoint which structures (ligament, joint or bone) are affected, and is expensive for the owner. Diagnostic ultrasound is a more effective way of determining abnormalities in this area; soft tissue damage and asymmetries can be found by viewing the joint with an ultrasound probe in the rectum.
Some horses may be conformationally pre-disposed to developing sacro-iliac conditions. Large-framed horses with long lumbar spans and weak quarters tend to be more at risk. Some horses may suffer a traumatic event, such as a fall backwards, which may cause injury to the hindquarters and sacroiliac pain.
Human use and management can also play a significant role in the development of sacroiliac disease. The horse's musculoskeletal system was designed to cover ground efficiently and to quickly escape predators when required (Anderson). Under natural conditions, horses would sometimes spend hours moving from one source of water to the next, often at a trot. The back displays very little movement during trotting, making this a very efficient, sustainable gait for travelling over long distances (Anderson) while during a canter, the back shows much more flexion and the horse is enabled to quickly sprint away from danger - but this gait is best suited to short, "emergency" situations and not intended to be sustained by the horse for extended periods of time. The horse's back is the "true source of motion, equilibrium, and co-ordination" (Denoix, 1997). The hind limbs of the horse are often compared to the engine of a car, and the horse's sacroiliac joint is considered the transmission. Contractions of the pairs of antagonist muscles in this area produce protraction and propulsion of the horse's hind limbs. Movement is transferred forward down the horse's back, the thoracic and cervical spine aiding the horse in keeping its balance.
Human use of the horse for pleasure or competitive purposes counters the horse's evolutionary design in that horses must perform work at the canter often, and for longer durations, than a horse would naturally. During a course of jumps or a dressage test, a horse must canter for often lengthy periods of time, performing repetitive movements which it would never perform under natural conditions, such as lengthy periods of collected work, or the act of clearing jump after jump in succession -- all while balancing the weight of a rider on its back. Horse sports today are designed to challenge both horse and rider, and horses are often pushed beyond their physical limits, leaving them vulnerable to injury and disease.
This problem is worsened if an animal is not properly conditioned to perform the work being asked of it. In his book, Physical Therapy and Massage for the Horse, Jean-Marie Denoix points out that "the weight of the rider hinders lumbo-sacral flexion". A rider on the horse's back adds weight and exerts a downward force on the muscles of the horse's back, which yield away from this pressure, becoming tense and rigid. If a rider is tense, this emotional energy is transferred to the horse, and if ill-fitting tack is used, pain is amplified. An uneven rider can put uneven weight on a horse's spine, and an uneducated rider may use many mechanical aids excessively or incorrectly , in many cases causing undue pain and suffering to the horse. Devices which force a horse's head down, such as tie-downs, martingales, side reins adjusted too tightly, draw reins used too often or by inexperienced riders, and certain controversial training techniques such as "rolkur" in dressage, are all factors which can negatively affect a horse's well-being and may contribute to an animal developing sacroiliac injury. In the horse, as in the human, "emotional and psychomotor problems reveal themselves in the back"(Denoix, 1997). A sore, tense or fatigued horse has rigid movement, often with its head thrust skywards and its back stiff and "hollow". Vertebral pathologies are the result of continuation of these conditions, and in order to avoid further damage to the spine, careful preventative measures should be employed.
When selecting a horse, conformation should be analyzed to determine if a mount is suitable for the task it will be asked to perform. Form must suit function: an animal with a short back relative to its total body length, and short lumbo-sacral span is able to coil its loins with greater ease than one who has a long back and a lumbo-sacral span measuring in excess of 4 inches (to determine lumbo-sacral span, one must locate on the horse, the lumbo-sacral space - this can be felt as a small "dip" just before the highest point of a horse's croup. Using a piece of string or even simply drawing a line across the top of the rump with a finger from hip to hip, a triangle can be formed from hip to hip, hip to LS joint and from LS joint to the other hip. The distance from the LS joint to the midline of the triangle is the lumbosacral span. Ideally, this space should be less than 4 inches, and for a well-coupled animal capable of much athleticism, it can be around 1-2 inches or less.) This type of animal is more suited to performing the advanced level collected movements required during competition such as dressage and showjumping, and is likely to be much more athletic in general.
When a horse's hind end is correctly engaged (in dressage terms, when he is working "through"), his abdominal muscles are held tight, and his longissimus dorsi muscle is flexed upward, supported by the iliopsoas muscle running from the pelvis under the spine. His neck is arched, and the so-called "chain of muscles" is at work. He is better able to support the weight of a rider, provides a more comfortable gait for the rider to sit, and is less likely to suffer pain or injury as a result. Conversely, if a horse is unable to flex at his lumbo-sacral joint due to the way he is put together, he is unable to engage the ventral chain, and his abdominal and back muscles are likely to suffer.
A horse with a long lumbo-sacral span may be more comfortable for the novice rider, as its gaits will be flatter and therefore easier to sit for a rider with an inexperienced seat; however, this type of horse will have trouble with any exercises where it must collect itself such as rollback turns, advanced dressage movements, barrel racing, quick stops and turns, going down steep hills, etc. Horses with long lumbo-sacral spans tend to jump longer and flatter, and for this reason may be favoured in the entry levels of the hunter show ring. Different breeds have developed with different requirements for back lengths, although there are always variations within a breed. For example, the standardbred horse, bred for trotting or pacing distances of 1 mile in under 2:00, tends to have a long back and long lumbosacral spans are frequently seen also. Some of the fastest horses have had this sort of conformation, which has influenced most of the horses we see racing today. The standardbred was developed to cover flat racetrack surfaces efficiently at high speed, and races are contested over oval-shaped tracks with two long straight-aways and two gradual turns. A horse with a longer back may have a greater stride length, and so will cover more ground, which can pay off in a flat race. Many of these animals show very little lateral flexibility, and many are not capable of much vertical flexion in their hindquarters compared with their warmblood counterparts, but for their intended purpose, these traits are not always necessary. While it is not impossible to condition a Standardbred to perform efficiently under saddle when its racing days are over, it may take a longer time and very likely a lot more effort on the part of the rider, especially in the initial stages. Many off-track standardbreds tend to excel at endurance riding, trail riding and as school horses due to their excellent temperaments and tough competitive natures. The level to which a member of this breed may rise in competitive circles may hit a plateau at some point, simply due to the fact that the intended purpose for which a Standardbred was designed is different than that of an animal bred specifically for jumping or dressage, but there are always exceptions to the rule, and while particularly well-coupled Standardbreds do exist, they are perhaps not often favoured by trainers looking to race on the flat.
In summary, if looking to avoid sacroiliac pain, one should avoid horses with excessively long backs and weak-looking hind ends as this type of conformation will put excess stress on the underlying tissues and joints, eventually leading to injury. For competitive purposes, riders should select horses with the best conformation for their sport that their pocketbook will allow, and attention must be paid in particular to hind end conformation, as this is the source of the horse's power. There are no guarantees, and no perfect horses, but conformation assessment prior to purchase can be key to preventing sacroiliac pain.
Proper saddle fit is very important to preventing pain in the horse's back, but is not recognized as a primary cause contributing to sacroiliac dysfunction as the structures involved in sacroiliac disease are mainly located further back than the area on which a saddle sits. A poorly fitting saddle is more likely to produce secondary sacroiliac pain, as soreness in the longissimus muscles supporting the spine may refer pain to the sacroilliac area.
A proper warm-up and cooling out period are essential in the prevention of equine back injuries. Most riders would agree that a warm-up period under saddle is a necessary and important part of a horse's fitness program, but many may not consider that the muscles of a horse's back and hind end should be warmed up and stretched prior to weight being placed upon them; this can be an important preventative maintenance technique. For prevention of sacroiliac pain, a rider should pay particular importance to stretching the hind legs, back and hip area in order to maintain suppleness of the soft tissue in this area. Once a rider has mounted, active stretching exercises may be practiced to increase strength and suppleness and to ease an animal into more advanced movements. When muscles work, they become shortened. To maintain flexibility, they must be stretched to their original, pre-workout length. A sufficient cool-down period of walking, either mounted or in-hand, and post-workout stretching helps a horse to maintain suppleness and reduces lactic acid buildup in the muscles which speeds up a horse's recovery time. Cold muscles should never be stretched, as this can cause injury: but turning a horse out prior to work, or handwalking/light lunging prior to performing passive stretching exercises such as belly lifts to warm up the horses' back prior to exercise, may lessen the chance of injury to a horse's back and sacroiliac area by helping to maintain muscular tone and flexibility. A rider must constantly observe and get to know what is normal for each individual horse, and know when a horse has reached its limits. This is vitally important to preventing injury. A rider must know when to stop pushing an animal.
Equine massage therapy, physiotherapy, and many other forms of bodywork are useful tools for a rider to employ in order to prevent sacroiliac injury. A trained equine massage therapist or bodyworker with a good knowledge of equine anatomy uses touch to detect heat, pain, tension, tenderness, or even energy imbalances over a horse's back. Being aware of a problem is the first step to correcting it. Getting to know what is normal for each horse's back will allow a rider to recognize the first signs of trouble and take steps toward correcting a small problem before it develops into a major issue.
Working a horse properly may be the most important step in preventing sacroiliac pain. A horses' muscles work in opposing pairs to produce movement, and all locomotor muscles are connected in what is sometimes called the "chain of muscles". It is very important for these muscles to be allowed to strengthen and develop gradually, as well as symetrically, and from several angles. Too much work in one direction, such as always working a horse to the left, can cause uneven muscle development, eventually leading to strain and injury. The adductor and abductor muscles of the horse must be developed through use of lateral exercises incorporated into the training programme. Strenghtening the abdominal muscles of the horse can help to strengthen the lower back muscles which support the spine and the sacroiliac area. A few useful exercises to help prevent sacroiliac pain in horses include: riding on hills (increase of speed uphill/decrease of speed downhill); work over poles on the ground or raised slightly above; gymnastic exercises and cavaletti; backing up (reinback).
Treatment options for sacroliiac pain in the horse are limited, can be expensive, and are of varying effectiveness. Injections into the sacroiliac joint have been attempted with varying rates of success - possibly due to lack of adequate diagnosis. Many people inject SI joints to avoid the cost of diagnosis, as it can be less expensive to inject than to undergo a nuclear scan or rectal ultrasound.
Acupuncture is a treatment option which has proven to be successful for many horses. Chiropractic techniques are another area which may be of some benefit, again depending upon the root cause of the pain. In order to resolve a sacroiliac issue, treatment must be practiced in conjunction with a careful physical and lameness examination(Sellnow, 2002) and the training program of the horse must be brought under review as well.
In Canada at present, both acupuncture and chiropractic treatments for horses must be practiced by a licensed veterinarian or human chiropractor, while body work, energy healing, and massage therapy are currently unregulated by any governing body. In this regard, horse owners must choose carefully a practitioner of so-called "alternative" therapies, in order to avoid further injury and to allow their animals a greater chance of recovery.
For minor sacroiliac pain, there are many hydrotherapy techniques which can be used relatively safely, again with varying results. Magnetic therapy (using magnetic blankets over the horse's back) may help to maintain a horse with chronic sacroiliac pain. Magnets are said to increase circulation to an area, thus relieving pain, and may be most effective in cases of pain due to arthritis/bone issues. The effectiveness of magnetic therapy lack significant scientific proof, and much of the support for it has been anecdotal. Applying poultices or ice to the back in the case of acute injury, or sweating the back by applying liniments and a plastic bag are other techniques of varying effectiveness which may be reccommended by a veterinarian/alternative practitioner in treating sacroiliac pain.
Complete stall rest may be recommended for some horses, for instance in the case of ligamentous damage, etc. Alternatively, a program of physical rehabilitation/therapy may be reccommended, in the case of chronic pain or pain caused by arthritis, etc. It may be helpful to look at a horse's diet to determine if there are nutrients lacking which may aid in the formation of certain tissues or in proper bone/cartilage formation of the horse. This is why proper diagnosis is so important in the case of sacroiliac pain, and also why it is such a difficult problem to treat.
Due to the nature of sacroiliac pain in the horse, it is much easier to prevent injury in the first place, through careful selection of animals and proper management of a horse's fitness routine, than to treat an animal once injured. Riders should do as much as possible to educate themselves on conditioning animals for their chosen sport, and should do everything in their power to ensure that animals are not pushed beyond their fitness levels in order to maintain sacroiliac and overall soundness for as long as possible.
References
Back Pain and the Sacroiliac Joint in Horses, author and date unknown, MyHorse.com featured article,
http://www.myhorse.com/back-pain-and-sacroiliac-joint-horses.html
Pain associated with the sacroiliac joint region: a clinical study of 74 horses. Dyson, S. and Murray, R. Equine Vet J. 2003 May;35(3):240-5. From: PubMed.gov http://www.ncbi.nlm.nih.gov/pubmed/12755425?dopt=Abstract
Pain Associated with the Sacroiliac Joint Region: A Diagnostic Challenge, S.J. Dyson, in: In: 50th Annual Convention of the American Association of Equine Practitioners, 2004 - Denver, CO, USA, (Ed.). Publisher: American Association of Equine Practitioners, Lexington KY. Internet Publisher: International Veterinary Information Service, Ithaca NY (www.ivis.org), Last updated: 4-Dec-2004; P1463.1204 found at: http://www.igloo.lv/horses/harm/sacroiliac.html
Principles of Conformation Analysis, Volume III. Deb Bennett, PhD. 1991. Gaithersburg, MD: Fleet Street Publishing Corporation.
Physical Therapy and Massage for the Horse. Jean-Marie Denoix & Jean-Pierre Pailloux. 1997. North Pomfret, Vermont: Trafalgar Square Publishing.
Equine Back Problems. Leo Jeffcott, BVetMed, PhD, FRCVS, DVSc, MA, DSc. The Horse.com - May 01 1998, Article #491. http://www.thehorse.com/Print.aspx?ID=491
The Equine Spine -- Back To Work. Stephanie L. Church, Editor-in-Chief. The Horse.com - March 1, 2001 Article #59. http://www.thehorse.com/Print.aspx?ID=59
Your Horse's Back. Kathy Anderson, PhD. From Equus Magazine online. http://www.equisearch.com/horses_care/health/anatomy/horse_back_112009/2
Stretch Exercises for your Horse: The path to perfect suppleness. Karin Blignault. 2003. London: J.A. Allen.