Core Body Strength A horse s natural centre of gravity is slightly behind the shoulder and approximately one third of the way down it s body. In order to accommodate the weight of the rider, we need to ask the horse to adjust it s centre of gravity and balance. To do this, you need core body strength. In most recent years, much research in fitness training has discovered the value of core training. The body's core includes the vertebral column, four main abdominal muscles, the sublumbar muscles, the pelvic floor muscles, the epaxial muscles, the thoracic sling, and the neck muscles. Collectively, these muscle groups keep the back straight and strong.
The abdominal muscles: These four muscles cause the body to move forward and back, up and down, and to bend from side to side. They also round the back and flex it laterally. No other muscle group provides such a diverse group of functions. 1. Rectus abdominus - Flexes and stabilizes the thoraco-lumbar and lumbar-sacral parts of the spine, and contributes to bending to the same side. 2. Transverse abdominus - Contracts the abdomen upwards, and assists in stabilization and flexion of the spine. 3. Internal Obliques Raises the abdomen upwards, stabilizes and assists in flexion of the thoraco-lumbar region. Contributes to bending. 4. External Obliques - Raises the abdomen upwards, stabilizes and assists in flexion of the thoraco-lumbar region. Contributes to bending. 2 1
3 4 The sublumbar muscles: These muscles work with the abdominal muscles to round the back, and stabilise the spine. They both cause flexion of the hip joint and sacro-iliac joints. They also cause rotation of the lumbar spine and lateral rotation of the hind leg. 1. Iliopsoas 2. Psoas minor 1
The pelvic floor muscles: These muscles help with stability of the pelvis and hip. They can have a strong influence on balance. 1. Sublumbar muscles (as shown above) 2. Gluteal muscles Causes extension & flexion of the hip and contributes to protraction, abduction and rotation of the hind limb. 3. Tensor fascia latae Assists in flexion of hip, extension of stifle ad protraction of the hind limb. 4. Biceps femoris Flexes the stifle joint, extends the hip, stifle and hock joints and contributes to abduction of the hind limb. 5. Semitendinosus - Causes flexion of the stifle and extension of the stifle and hock joints as well as medial rotation and adduction of the hind limb. 6. Adductor (inner leg) Causes adduction and retraction of the hind limb and assists in extending the hip joint. 7. Sartorius (inner leg) Causes flexion of the hip joint, protraction and adduction of the hind limb, and extension & flexion of the stifle. 2
Gluteal Biceps femoris semitendinosus Tensor fascia latae The epaxial muscles: These are very deep muscles. These muscles contain the extensor muscles of the spine and are used to stabilise the spine, cause lateral bending and rounding. When they contract on both sides they cause extension of the spine, but when they contract on only one side they cause lateral bending. The multifidus is the main muscle, which stabilize and align the vertebrae. This muscle atrophies in horses with back pain. These muscles are all very important for working in a collective frame. 1. Multifidus Supports and stabilizes the spine and assists in extension. 2. Longissimus Assists in extension of the back and bending of the spine. 3. Iliocostalis these are divided into cervicus and thoracis. The iliocostalis cervicus extends the neck and bends the spine laterally and the iliocostalis thoracis extends the back, stabilizes the lumbar vertebrae and contracts the rib cage. The thoracic sling:
These muscles affect the position of the wither and ribcage. They join the legs to the trunk. 1. Serratus ventralis - Assists in bringing the scapula forward, raising the neck and stabilizing the trunk. 2. Pectoral muscles Causes adduction of the leg. And stabilization. 3. Subclavius Suspends the trunk, stabilizes the shoulder joint, and assists in adduction of the forelimb. Serratus ventralis cervicus Serratus ventralis thoracis Subclavius Pectorals The neck muscles: These muscles affect the horse s balance and weight distribution. 1. Splenius Elevates and extends the neck, and can cause rotation and bending of the neck. 2. Spinalis Extends the poll and stabilizes the neck. 3. Brachiocephalicus Flexing and bending the neck and head and protracting the forelimb. 4. Trapezius Causes elevation and abduction of the shoulder and leg, also assists in flexion of the neck. 5. Sternomandibular Opens the mouth, flexes the poll and neck and stabilizes the neck. Also causes flexion of the neck to the side. 6. Rhomboids Causes elevation and abduction of forelimb, as well as elevation and flexion of the neck. 7. Serratus ventralis cervicus Assists in bringing the scapula forward, raising the neck and stabilizing the trunk.
Spinalis Brachiocephalicus Splenius Serratus ventralis cervicus Rhomboids Sternomandibular Trapezius Like an accordion, these core muscles contract and release with each step to pull the legs forward, aid in breathing, and maintain stability to the trunk. Because they are attached to the ribs, the femur, and the hip, they are prone to overuse and can suffer athletic injury just like the limbs. In core strength and flexibility training for your horse, care should be given to a proper warm up before implementing difficult strength work. Muscles should always be quite warm before beginning aggressive strength training, and stretching should be done before the cool down. Massage therapy can be beneficial in maintaining the necessary flexibility to these important muscles. The fascia woven through the muscles often becomes stuck to the tissue beneath and can be mobilized by gentle massage. Be aware that the flank is a ticklish area and that you should be aware of your safety when working in this area. Stay Apparatus The stay apparatus of the horse is what enables it to sleep standing up. In the wild, horses do not spend a large amount of time lying down in case they need to escape from predators quickly. The stay apparatus enables them to relax their entire body whilst still remaining standing. It stabilizes both the front and hind legs and involves a system of tendons, ligaments and muscles in the horse's leg. The stay apparatus of the hind leg is slightly more complicated and involves three different elements. 1. The first element, the stifle joint locking mechanism, allows the weight of the caudal body to rest, essentially, on the locked joint.
2. The second element, the reciprocal mechanism, ensures that the stifle and hock joints will move in unison, and the leg will move in a smooth, coordinated manner. The first and second elements work together. 3. The third element involves other ligaments/tendons in the distal limb." The stay apparatus is very complicated with 32 individual soft tissues involved. Below is a picture of the hind limb stay apparatus. University of Pennsylvania