Equestrian sport and horse racing are sports where, in the blink of an eye, events can be won or lost, explains equine musculoskeletal therapist Laura Stephenson.
Sport and racehorse health and performance can be significantly affected by subtle problems which lead to poor performance and loss of progress. This slows horses down and costs money.
An understanding of biomechanics and how muscles work can help keep horses sound and fitter for longer periods. Optimum performance requires all body systems to function at, or close to, maximum capacity. Hence the horse’s body comes under greater stress and strain from intensive training.
Being able to identify problems early allows for quicker preventative intervention, enabling the horse to maximise his/her athletic potential sooner rather than later.
Human athletes benefit from support teams that recognise and treat athletic injuries such as muscle fatigue, stiffness, soreness, and micro-tears before they interfere with training. With horses, it is less acknowledged that muscle injury can be a reason for unsoundness and poor performance.
Lameness is not always a response to pain but can be a compensatory mechanism because of unloading affected limbs or structures.
Unlike people, horses cannot tell us when they are experiencing discomfort. Musculoskeletal pain is often missed or misread, leading to chronic pain sites and loss of performance.
Prioritising musculoskeletal health
Musculoskeletal health is fundamental for a horse’s mobility and dexterity, and a good indicator of their overall health.
Muscles act by contracting and changing the angle of joints to create the body’s internal and external movement. Movement is initiated through the combined effect of the activities of skeletal muscle, tendons, and ligaments. Not only do muscles work in pairs, they, work in chains to facilitate precise and continuous flowing movement. Deep muscles and those close to joints are postural muscles, responsible for supporting and stabilising joints. When one muscle group contracts and flexes the opposite muscle group extends and relaxes.
When there is a restriction in a muscle or in one part of the chain, the horse will experience musculoskeletal pain or discomfort and tend to engage different parts of their body to avoid using sore areas. This habit of “compensation” overloads precision structures such as tendons, ligaments, and joints.
Youngsters born with or acquiring an abnormality that affects the musculoskeletal system will need immediate help to grow and respond without compromising future ability.
If not remedied early, irregularities will place excess strain on joints and ultimately interfere with speed and agility.
Flat racing horses are raced from 2 years old or younger and the amount of force and impact of galloping at high speeds causes concussion on immature joints and still-developing soft tissues. Repetitive concussion results in an imbalance and the domination of a favoured limb will lead to tears, chips, and fractures. It is not uncommon to see conformation changes in lower limbs from “back at the knee” to slightly “over at the knee” between the weanling and 3-year-old.
Maintaining a healthy flow of synovial fluid, in and around joints, is crucial. When fluid becomes either too thick or thin, it cannot lubricate to protect joints. Specific therapy techniques increase the range of movement of joints by lengthening and stretching out adjacent muscles. This encourages the synovial membrane to release fluid thus allows articulating bones to move freely over each other with reduced friction and pain.
As a holistic therapist I consider the following compensatory movements when assessing a horse’s mobility:
(i) Tight shoulder muscles transfer tightness to upper limb muscles, eventually down to flexors and tendons. Inevitably, the horse will suffer tendon injury.
(ii) A horse with pain in its lower forelimb (hoof, pastern, fetlock, or knee) will experience compensatory tension in the upper limbs. Upper limbs control movement but when limited through discomfort the horse is unable to lengthen its limbs. This will cause a decreased stride length and if unnoticed/untreated can manifest into the shoulder and further.
(iii) A horse with inflamed hocks is injected with anti-inflammatory medications by a vet. This helps reduce pain and inflammation temporarily but will not address the underlying reasons. Upper body areas such as the spine, sacroiliac, lumbar, pelvis, gluteals, stifle and hamstrings will experience secondary pain and restrictions because of gait compensations caused by hock pain.
(iv) Tightness in adductor muscles that stabilise the pelvis. Tension in these muscles can instigate pelvic asymmetry with secondary compensations in gluteals and hamstrings. Horses will have difficulty flexing hip and stifle joint thereby restricting the range of motion.
Balancing sound structures
It is important to start the horse’s training with longevity at the fore of priorities. Young horses often develop asymmetrically, and this creates weak areas in the body. Changing undesirable posture into a functional one not only helps relieve physical discomfort but encourages more efficient body and brain use. Whilst they may appear to be willing, back and core muscles are still developing. To ensure symmetry, it is relevant that appropriate muscles need to be strengthened and conditioned.
Young horses experience inconsistent and awkward growth and development stages. From an early age, a right/left preference develops. Repetition of constant weight-bearing will make muscles on this preferred side become more developed and stronger. The imbalance will generate fatigue, an apparent decline in performance and an increased risk of injury.
The most efficient horse has a range of motion in the forehand that corresponds to the range of motion in the hindquarters; but not all horses have strides that match. Thoroughbreds have specific conformational traits to help with stretch and length of stride.
In racing, the burst of acceleration the horse needs to push out of the stalls, causes hindquarter muscles to become hypertonic and tight. Rather than engaging the hindquarters to push forward, the racehorse uses its neck to pull the rest of the body forwards. This results in a heavy forehand and typically the horse is weaker around the back and hindquarters. Locomotor muscles become weak because of the focus on stamina and speed.
A large percentage of overall body weight is carried by the shoulder. Saddle load is concentrated over the withers, which is especially sensitive to pressure – a problem exacerbated by the rider standing in the stirrups. Gaits can become uneven and the length of stride correspondingly shorter. Tension in shoulders and withers is often linked to tension in the neck and back. Horses will lack impulsion from behind since the shoulders need to be free for hindlimb engagement. If this is not treated, it can lead to soft tissue strain and lameness.
Large superficial muscles of the hindquarters provide the propulsive forces required for speed. Hindquarters become imbalanced because of the need for quick power to push from the starting stalls. Neurological communication to the hind end is limited compared to muscles in the front which makes it difficult for the horse to be aware of muscles it is using in the hind end.
If there is discomfort, lack of balance, poor conformation or injury, the horse easily compensates by overusing other muscles. Compensatory patterns in the hindquarters place stress further up the spine, compromising the sacroiliac (SI), ligaments and tendons, subsequently overloading the forelimbs predisposing further injury.
As hindquarters are incorrectly used the hamstring muscle group becomes over-developed (hypertonic) to help balance the body. Through this lack of development gluteal muscles atrophy (weaken). The absence of strength in the pelvic structure and the dysfunction of deep stabilising muscles often triggers postural and performance problems. Teaching the horse to use its core stabilises and supports the pelvic region by helping the horse use lumbar muscles more appropriately.
The horse’s spine governs the overall co-ordination of limbs and gait. The combination of weak and overtight muscles can cause a deviation in posture and in the skeletal system.
Tightness through the back influences the horse’s ability to bend and can greatly affect hindlimb movement and neck posture, while incorrect positioning of the head and neck can restrict breathing and result in airway disorders.
Connective tissues in this area directly attach to the front and hind legs which mean any tension here will cause short and stiff strides. Movement of the soft palate because of a fixed head/neck set will also make breathing difficult. Massage and cranio-sacral techniques can offset these issues.
Horses will continue to move and perform with muscle strains or spasms, but during exercise, these small spasms recruit more fibres until increased discomfort begins to affect posture, gait, attitude and performance. Restrictions will continue until the horse receives appropriate bodywork.
To practically assess whether the horse is functioning as it should, I look at key areas to build up the ultimate picture. Observing static and dynamic postural observations, movement analysis, examining muscle recruitment patterns and evaluating joint range movement, allow me to bring all elements together – pain, function, balance and posture.
These sequences are repeated until I feel comfortable that the posture exhibited is consistent. Addressing postural and biomechanical dysfunction easily helps to identify common physical one-sidedness. Behaviour and postural changes may signal an insignificant or temporary issue or may indicate the first signs of a serious injury.
Therapeutic interventions are natural, drug-free and allow the opportunity to palpate and isolate areas that have become tight, imbalanced, sore, or restricted through training. Thorough palpation of the horse’s superficial muscles assesses temperature, texture, tenderness, and tension across the body when looking for muscular dysfunctions. This differentiates the areas that need focus.
Trigger points are very common and using deeper palpation we find muscle soreness within muscle groups rather than in isolated areas and within the fascia, the body’s entire connective tissue. Blood flow and circulation are automatically improved when there is more space for blood, oxygen, nutrients and water to transport to the cells throughout the horse’s body.
Conditioning for performance
If we focus on the science of building better athletes, we can develop a better racehorse.
Strengthening and conditioning muscles equally, bestows full range of motion, correct skeletal alignment, maintains correct biomechanics of joints and maintains comfort. This reduces the risk of soreness and injury.
It is evident from working with racehorses where the emphasis is put on fast work, that many lack balance, flexibility and suppleness. There is an absence of core strength which could crucially result in the development of kissing spines (impingement of the dorsal spinous processes). The inability will cause tension and curvature of the spine and pelvic tilt, often seen in thoroughbreds.
“Impinging spinous processes (ISP) have been found in 86-92% of racehorses at post-mortem and in 37% in normal horses. Lameness results in reduced ability to use the thoracolumbar muscles normally. Saddle slip to one side occurs in approximately half of horses with hindlimb lameness which is likely due to asymmetric thoracolumbar movement or muscling. Osseous spinal pathology has been shown to cause measurable left/right asymmetry in the multifidus at, or close to the level of pathology in thoroughbred racehorses”. (Jackson, AF; 2020; Evaluation and Treatment of Horses with Back Pain).
Conditioning grants the body time to adjust and provides a much safer, more measured response to exercise. It is less exhausting on the cardiovascular system and will lessen the chances of injury, allowing time for musculoskeletal tissues to respond. A strong core reacts quicker, offers more control over the centre of gravity and generates more power.
Abdominal muscles and deep back muscles play a vital role in stabilising the spine, back and pelvis. and this helps create more propulsion from hindlimbs.
Isometric exercise can be implemented without eliciting additional pain and joint damage by realigning the body from the inside out. This approach builds strength and stability and couples the horse’s natural movement, enhancing vertebral joint range of motion by rounding (flexion), hollowing (extension) and side to side (lateral bending). Incorporating these exercises will contribute to more effective training and improve the horse’s performance, thereby, reducing the risk of injury. Performed from the ground, they improve core stability and assist ridden work.
All these common performance-limiting issues are preventable and treatable, with correct therapy administered at the right time.
Laura Stephenson EMAP, MIRVAP (MT) is a British Registered Equine Musculoskeletal Therapist. Laura treats horses worldwide and can be reached by email: email@example.com.