Dressage is seen by many as the ultimate equine discipline. It was originally confined to the military, where soldiers would train their horses to perform movements used in battle. It became an Olympic sport in 1912, where only military officers could compete until 1952 when entries were opened to the public. Throughout the twentieth century dressage has developed into a sport which can be enjoyed at all levels, from grass roots to International Grand Prix, and with ambassadors for the sport such as Valegro, its popularity continues to grow.
Dressage demands total harmony between horse and rider, and requires the equine athlete to have balance, suppleness, power and focus. To enable the dressage horse to be collected, have balance and freedom of movement, extra load is taken onto the hindquarters, which in turn increases the strain on the skeleton and soft tissue structures in these areas. To try and prevent injury, the aim of training is to develop and strengthen muscles to cope with the increased load, and to maintain flexibility and suppleness in ligaments and tendons to cope with the demands of the more complicated movements. Despite training, injury does often occur. Due to the nature of the discipline certain injuries are more commonly seen in dressage horses than others. Four of the most commonly seen are; damage to the suspensory ligament in both the fore and hindlimbs particularly in the upper area (proximal suspensory desmitis (PSD)), problems associated with the coffin joint (distal Interphalangeal joint (DIPJ), osteoarthritis of the hock joints, and thoracolumbar and sacroiliac pain.
The suspensory ligament is a broad fibrous structure that lies beneath the flexor tendons of both the fore and hind limbs. It originates from the top of the cannon and continues down between the splint bones dividing into two branches which attach at the level of the fetlock joint. The main function of this is to prevent over extension of the fetlock at rest and during exercise. Dressage requires the horse to increase the load on the hindlimbs, especially at advanced levels, and so greatly increases the strain on the suspensory apparatus.
Damage to the upper portion of the suspensory ligament (Proximal Suspensory Desmitis (PSD)) of the hind limb is thought to be caused by an accumulation of repetitive strains in this area. This will often cause a mild lameness that may affect both hindlimbs, and as a result the injury is not often noticed as lameness as such, but a loss of performance. PSD of the forelimb, is more often seen in younger horses in training. These injuries are often acute and present as a unilateral lameness. Often horses that are over expressive with their forelimb movement will sustain this injury by over extending their knee during movements such as extended trot.
‘Foot pain’, resulting from synovitis or osteoarthritis within the coffin (or distal interphalangeal joint (DIPJ)), is a commonly diagnosed problem in horses competing in all disciplines. Within the rigid hoof capsule, the DIPJ has to cope with the load of the horse, along with the push and pull of different forces applied by the attaching ligaments and tendons. This alone is thought to be a reason why inflammation and resultant lameness is so common in the area. Any change in arena surface or poor foot conformation, such as mediolateral or dorsopalmar/plantar foot imbalance can also predispose the horse to problems. If the forces applied to the DIPJ are uneven or change suddenly this cause inflammation of the joint capsule and disruption of the joint surface which can result in arthritis if not treated.
Another area commonly affected by joint pain in the dressage horse is within the two lower hock joints. These are low motion joints with take considerable load during common dressage movements. When any joint inflammation arises it causes pain and a resultant lameness. This lameness will often be subtle and bilateral, often picked up as a shortened stride, struggling to perform a collected canter or a general loss of impulsion. The degree of arthritis in the joint is not directly proportional to the degree of lameness, as some horses that are significantly lame, with pain originating from this area, have little to no changes on their radiographs. This subtle bilateral lameness may also mimic back pain, another common finding in the dressage horse.
Thoracolumbar and sacroiliac pain is a problem often encountered in the dressage athlete and can be a primary or secondary issue. These areas of the spine are located beneath the back of the saddle, continuing to the sacroiliac joint where the spine meets the pelvis. This area needs to be strong and supple to enable the horse to appear effortless when floating through a test. Pain here may present as general poor performance, an unwillingness to move forward or to perform certain movements, resenting the saddle or becoming nappy and irritable. Primarily, several issues can result in back pain including muscular strain, an ill- fitting saddle, osteoarthritis, sacroiliac disease or a combination of these. It can additionally be secondary to concurrent or previous hindlimb lameness. Diagnostically it can be a challenge, requiring assessment of tack and rider, and using imaging such as radiography, nuclear scintigraphy or thermal imaging.
Overall dressage as a discipline can be enjoyed by everybody at every level. To allow them to perform a good test the horse or pony must be finely tuned and faultlessly functioning. Any mild lameness can cause a problem and so it is important to train and prepare well, ensure good foot confirmation and keep an eye for any change in behaviour or gait.