Equine Symptomatic Lameness
By Jochen Schleese, CMS, CSFT, CSE
Why is my horse lame?
Why does he keep stumbling?
Why does he seem to trip over his own feet?
The horse suffering from back pain or injuries can exhibit symptomatic lameness, which can also manifest as behaviour issues including stubbornness or resistance. When the horse is displaying symptoms of lameness and logical treatments are not working, the horse’s owner may turn to injections, anti-inflammatory creams, or chiropractic adjustments at the sacroiliac joint. But by observing horse and rider at various gaits, the horse owner may perceive another cause of lameness – poor saddle fit.
Symptomatic lameness often appears as a problem in the right hind leg. We have found that horses with symptomatic lameness in the right hind fall into the majority of horses (70 percent) more strongly muscled on the left shoulder. This unevenness can be easily seen by viewing the horse over its rump. There are many theories concerning the natural asymmetry of horse musculature – some scientists think there is a natural genetic predisposition, or that it is due to the way the equine embryo grows in the womb. It can also be exacerbated as a result of the influence of domestication and training of the horse. Regardless of the origins, this asymmetry has definite implications for saddle fit.
Above and Below: This saddle’s gullet channel is too narrow and the saddle has shifted to the left. Photos: Schleese Saddlery
When the horse is in the cross-ties, the average fitted saddle appears to fit well. A chain reaction starts when the horse moves, beginning with a scapular rotation upwards and backwards. Saddles that are not adjusted to properly fit the larger shoulder will be tight and put more pressure on it. Additionally, the larger shoulder will push and therefore twist the saddle to the right. This has further implications for the rider’s position and balance, but this article will focus on the repercussions for the horse.
Shoulder-blade rotation and movement during different foreleg motion. It is obvious that a saddle with an incorrectly adjusted tree angle, incorrect tree width, or when its tree points are angled forward, as in this illustration, can cause potentially serious issues at the shoulder.
The shifting of the saddle to the right causes the left panel to impinge against the left side of the horse’s spine, reducing proper function, with resulting inflammation over the sacroiliac. This also occurs in the opposite direction, although less often.
To compensate for the saddle twisting to the right against the spine, the rider leans to the left to maintain balance, causing increased pressure on left side of the horse’s back. This may result in a subluxation at the sacroiliac joint and pelvic intersection, causing a misalignment of the horse’s back.
Infrared thermographic imaging showing increased temperature in the region of the upper right sacroiliac joint due to sublaxation.
By understanding the key points of saddle fit, the horse owner can recognize the basics and help determine the causes of symptomatic lameness and how they can result in behavioural issues if the saddle fits poorly. Most important to recognize are the tree points (width and angle) and the saddle support area of the horse. Although most riders know there should be two to three fingers’ width of clearance at the withers, there also must be sufficient clearance all around the withers. The tree point angle at the gullet plate needs to be parallel to the shoulder angle – not the wither angle – in order to allow the shoulder to properly move. The cartilage will protect the shoulder bone as it moves between the deep-lying spinalis, rhomboid, and longissimus muscles and the superficial trapezius during motion of the horse. However, if the tree points are forward facing or too narrow, this cartilage can be severely and irreparably damaged over time. One behaviour that can result from poorly adjusted tree points is what is termed stubbornness.
In addition to two to three fingers clearance on the top of the withers, a saddle must allow enough clearance on the sides of the withers to accommodate the shoulder rotation and allow full and free range of motion. Photo: Schleese Saddlery
Remember, this area over the withers is where the stallion bites the mare to immobilize her and prepare her for breeding. It’s the same result (with different inputs) – the rider is on top urging the horse forward – reflexively however, the horse doesn’t want to move.
If the saddle is too long for the saddle support area, the most commonly affected vertebrae are the last two thoracic and the first two lumbar (T17-T18-L1-L2). Additional issues arise when the panels twist or fall to the side and shove the vertebral spinous processes to the left or the right because of greater muscling at one shoulder. The resulting pain also causes the horse to protectively tighten the back muscle (longissimus dorsi), which further pulls the vertebrae out of alignment. Therefore, either direct trauma or secondary muscle traction are to blame for a resulting occurrence of lameness.
One of the most common reasons for the indication of a subluxation in the spine or SI joint is because the gullet plate (tree points) have not been fitted to accommodate the larger shoulder (left here). This twists the saddle to the right, puts excess pressure on the back of the left panel and left side of the spine, which the horse tries to avoid by deviating to the right through the right shoulder.
If correctly fitted and centered, the channel of the saddle protects the dorsal spinous processes. However, when the rider sits too far back or the panels of the saddle are too long, the horse may experience tremendous pain over the lumbar transverse processes, which are not designed to carry the weight of a rider and saddle. The horse then hollows its back, hyperextends, and the result is sacroiliac, hock, and stifle problems. Although there could be health related issues not caused by saddle fit, it is worth considering the saddle as instigator before investigating other potential causes.
The saddle should sit in your horse’s saddle support area, with the tree points behind the shoulder, and no further back than the 18th thoracic vertebra. Photo: ©CanStockPhoto/Zuzule
Many veterinarians have not been trained in saddle fitting and may actually not recognize the consequences of poor saddle fit. Veterinarians are generally called in when the symptoms have become so dramatic and obvious that even a readjustment of the saddle may not immediately result in positive changes. The horse will need time to heal, and for some of the problems a chiropractic adjustment may prove more effective in eliminating an uneven gait, which is the visual manifestation of lameness.
What is muscle atrophy and what role does it play in lameness? If a saddle puts too much pressure on a muscle because of being out of balance, the horse wants to avoid and lessen this pressure – resulting in a protective postural change which affects his gaits and causes muscle contraction. These muscles then begin to atrophy, as they will experience circulatory inhibition and receive less necessary nutritional supplements. When the problem is fixed, the picture can change for the better.
Muscle definition can be considered either positive or negative, since muscles can develop correctly through training, or incorrectly as the result of adopting a protective posture as a measure against saddle pressure.
For more information, visit www.saddlesforwomen.com, or read Suffering in Silence: The Saddle Fit Link to Physical and Psychological Trauma in Horses, by Jochen Schleese.
Main article photo: Flickr/Just Chaos
This article was originally published in the August 2015 issue of Canadian Horse Journal.