Equine sports medicine has evolved over the past several decades to optimize equine performance and to provide rehabilitation from injury. Just as human athletes are offered a myriad of strategies to help with injury repair, horses have also been afforded the benefit of a variety of therapeutic options. Specific rehabilitation centers are springing up throughout the country to accommodate this fast-developing facet of the equine industry.
Each horse has its individual set of problems requiring attention, so a rehabilitation program is tailored with those specific issues in mind. There is no single recipe for rehab, and there is no guarantee as to the outcome—much depends on the injury as well as the owner’s commitment to the necessary duration and logistics of treatment. Progressive stages of rehabilitation and conditioning require monitoring and evaluation using objective criteria. In some cases, diagnostic imaging is helpful to inform about a horse’s progress and to develop and modify rehab protocols.
Rehabilitation works best by limiting the use of immobilization as much as possible while also protecting against overuse during recovery. Rest and confinement have a role, but it is important to optimize tissue healing and remodeling, neuromuscular control, coordination, flexibility, strength and endurance so that soft tissue structures are able to function properly as more effort is added to a rehabilitation program.
A dedicated rehabilitation facility usually has an atmosphere conducive to healing, with good ventilation, natural light, optimal ambient temperature and safe footing. Multiple modalities are offered, each with its own set of benefits. Many equine sport venues (USEF and FEI for example) have specific regulatory requirements for use of certain modalities, and this should be considered when managing competition horses.
A very basic, non-invasive rehabilitation procedure is massage therapy, which helps to relieve muscle strain, spasms and tension. Relaxed muscles also im-prove the range of motion of joints and other soft tissue structures, along with the opening of blood vessels to improve oxygen delivery to the tissues and removal of metabolic waste products.
Most horses enjoy massage therapy and respond with relaxation, reduced tension and lowering of overall stress.
Stretching, Mobilization and Manipulative Therapy
Mobilization uses passive range-of-motion techniques to restore movement to soft tissue structures and joints to reduce pain and improve function. Stretching exercises improve a horse’s flexibility and the range of motion of limbs, neck and back, as well as having a role in increasing core strength. Passive stretches can be accomplished with carrot treats to encourage a horse to bend its neck and trunk.
Stretches are also achieved using elastic resistance materials such as Equiband or with side reins or long lines to stimulate a horse to engage core muscle groups.
The use of cavalletis or ground poles also helps a horse improve proprioception; strength in the abdomen, back and limbs; and to increase joint range of motion. Studies show that the best flexion and hoof elevation is achieved when poles are about eight inches off the ground.
Chiropractic techniques provide higher velocity manipulation of tissues, particularly in the spine and tissues along the back. These actions are reported to improve flexibility, relieve muscle tension and lessen pain.
Care must be taken to apply mobilization and manipulation to address a specific diagnosis, and to refrain in the case of fracture, joint disease, bone infection, neurologic disorders, cancer or bleeding disorders.
Hand walking is the gold standard for getting an injured horse moving without concussion impact or trauma to musculoskeletal structures during prolonged layup. This exercise begins with five to 10 minutes and is slowly increased as injury monitoring and progress allows. Gradual increases in duration and intensity of exercise enable soft tissues and bone to heal without undue stress. As rehab progresses, a horse might be ponied from another horse, and usually by three to four months a horse can be ridden under saddle with progressive increases in pace and time.
Negotiation of slight inclines, going both up and down, is also helpful for muscle strengthening of rear limbs.
The use of athletic tape is becoming more common on horses with the objective of reducing pain, improving proprioception and improving muscle activation. Lifting the skin with tape might decompress underlying blood, lymph and nerve vessels while also stimulating mechanoreceptors in the skin.
Heat and Cold Therapy
Cryotherapy (Cold Therapy): An acute injury or surgery—within the initial two to three days—often benefits from cold therapy to decrease metabolic demands and to reduce pain, inflammation, swelling and edema, and to limit hemorrhage. Soft tissue structures—muscles, tendons, ligaments—respond especially well to cold therapy.
Cold can be delivered via cold water hosing, with ice water immersion or with simple devices such as commercial ice boots, cold packs or frozen vegetable packs placed over the injury and wrapped into place. It is important to place a layer of light fabric over wetted skin to prevent skin freezing yet still allow cold to penetrate. Treatment is applied for 20-30 minutes and repeated every two to four hours during the initial days of injury.
Commercial devices (such as Game Ready or Soft-Ride Ice Spa) that use a mechanical pump to deliver cold with or without compression work exceptionally well to reduce edema and to improve blood circulation.
Heat Therapy: Once inflammation has settled down from an acute injury, a next step is using heat therapy to improve circulation, dilate blood vessels, reduce edema and amplify metabolic processes (including nutrient acquisition into tissues). Metabolic rate in tissues is increased two to three times when tissue temperature is warmed to 104–113 degrees Fahrenheit. Higher temperatures result in tissue damage and horse discomfort.
Heat therapy applied for 15–30 minutes is particularly useful for muscle strain or spasms, tendonitis, bursitis and arthritis. Tissue stretch, elasticity and joint range of motion improve with warmth. This is accomplished using heat packs, heat blankets or achieving deep heat with therapeutic ultrasound.
Acoustic energy used at higher frequencies of ultrasound than what is used for diagnostic purposes is able to generate heat. Applied to an injury, this therapy warms deeper tissues and increases metabolic activity to depths beyond 5 cm for repair of wounds, muscles and tendons.
In addition to tissue thermal changes, there are non-heating effects such as increased blood flow, increased cell membrane permeability with amplified movement of blood and lymph through the area, and collagen synthesis and tissue regeneration.
Therepeutic ultrasound further improves joint range of motion, as well as mobility and repair of connective tissue. It is also reported to reduce pain by as much as 47% (in human studies), but similar results are not yet reported for use on lower limbs of horses.
Therapeutic ultrasound can also be used for its beneficial heating effects on soft tissue structures prior to exercise or for mobilization procedures. Heating effects are relatively short-lived—i.e., in minutes—so to optimize advantages, perform stretches immediately following therapeutic ultrasound.
For best results, clip hair away and use ultrasound gel for optimal transmission of sound waves from the transducer.
Acupuncture has proven beneficial effects to help ameliorate pain. Relief from discomfort enables implementation of additional rehabilitation techniques to improve range of motion and flexibility.
Extracorporeal Shock Wave Therapy (ESWT)
Another form of generating pressure waves to target a specific injury site of soft tissue or bone is with the use of extracorporeal shock wave (ESWT). This therapy is used to treat ligament or tendon injuries and to stimulate remodeling of bone. It is said to improve development of capillaries to optimize blood flow to an area and increase growth factors to encourage healing.
Shock wave treatment is known to have analgesic effects for up to four days, so it must be used cautiously in advance of competition and regulatory requirements.
An accurate diagnosis is important for best results so that ESWT can be targeted specifically to an area of concern.
Low-Level Laser Therapy (LLLT)
Use of infrared light lasers to stimulate healing of wounds and treatment of soft tissue injuries and osteoarthritis is currently in vogue.
Laser is an acronym for Light Amplification by Stimulated Emission of Radiation. Light emitted from a Class 3 or 4 laser is said to stimulate release of neurotransmitters that activate specific cell functions to decrease inflammation and pain. Good results have been reported for muscle and tendon damage and for healing wounds. It is also reported to have beneficial effects when used concurrently with stem cell administration.
Clipping and cleaning the area for laser treatment is recommended to ensure best light penetration. Dark hair color tends to block laser light. The wavelength used depends on skin color, as well.
Transcutaneous Electrical Nerve Stimulation (TENS)
Surface electrodes placed on a horse’s skin are able to transmit electrical current to stimulate peripheral nerves for pain modulation.
Electrical stimulation is provided as a) high frequency/low intensity current; b) low frequency/high intensity current to stimulate acupuncture points; or c) intense TENS as high frequency/high intensity.
TENS exerts its effects via gate control, i.e., stimulation of large, myelinated A-beta fibers that also synapse within the spinal cord in the same place as pain-transmitting, small, unmyelinated C-fibers. This then blocks pain transmission. Another effect is achieved though release of endorphins into cerebrospinal fluid.
While plenty of research has identified successful use of TENS in humans, there isn’t yet evidence of efficacy in horses. To ensure best results, clip the hair and apply ultrasound gel beneath the electrode pads.
Many rehabilitation centers are equipped with specialized pools or tanks for horse immersion to allow locomotion without impact. This helps retain aerobic cardiovascular condition without traumatic concussion on bones, joints and limbs. The water temperature can be controlled to optimize what is best for a particular injury and for the horse’s well-being.
When using a variable-speed underwater treadmill, a horse’s buoyancy in water allows some weight bearing but not so much as to cause pain on distal limb structures. The hydrostatic pressure of water helps with muscle strength, joint range of motion, motor coordination and postural control for balance.
Water resistance, which is 12 times greater than treadmill resistance in the air, provides a form of strength training of muscles. Hydrojets can further increase drag on limb movement for additional strength training. Water depth determines how much benefit is gleaned from use of an underwater treadmill.
Whole body vibration is used with the objective of improving muscle, postural and core strength and to stimulate bone osteogenesis. It should be noted that studies on vertical vibration frequencies have demonstrated increased cartilage degeneration in cases of osteoarthritis. Horizontal oscillatory vibration does not exhibit those detrimental effects. The biggest benefit reported to date is a significant increase in the cross-sectional size and symmetry of the multifidus muscles of the back with twice daily, 30-minute application for 60 days. By improving multifidus muscle function, a horse might achieve greater spinal stabilization and postural muscle ability to help deter osteoarthritis.
Hyperbaric Oxygen Therapy (HBOT)
A specialized chamber increases atmospheric pressure to deliver additional oxygen to the tissues to aid with tissue healing. Blood vessels can increase in size, number and function in soft tissues and bone; swelling and inflammation are controlled; white blood cells amplify protective actions against infection; and anaerobic bacteria are adversely affected. Oxygen intake by a horse is doubled with HBOT, thereby improving oxygen uptake in the tissues. HBOT is an adjunctive treatment to other medical treatment used to manage illness or injury.
There are many different rehabilitation modalities that are now being used in horses. Some have years of scientific studies to back up their efficacies, and others are still in the process of being investigated. Work with an experienced or boarded equine therapist to get the best results for your clients’ horses.