Editor's Note: The following is part of a series to help horse owners understand certain modalities and their purported uses. Horse owners always should seek the advice of their veterinarian before starting any treatments.
When supporting the foreleg, keep your knees bent and your back straight. Gently pull the forelimb through a complete range of motion in every direction it will normally move.
Sixteen years ago, when I began talking to trainers about stretching exercises for their horses, I was met with some skepticism. Why would a horse need to stretch? "He needs to run and run fast...They are not ballet dancers," they would say to me. As it turns out, speed is dependent on strength, and on agility. Straight ahead running demands a certain amount of agility for rapid stride turnover. Agility involves rapid change of limb position or rapid change of direction, and it requires mobility in the soft tissues that surround a joint. The greater the agility one possesses, the greater the ability to accelerate rapidly or to maneuver around or over an obstacle. Elasticity of the muscles, tendons, and ligaments allows not only for controlled quick movements, but for avoidance of muscle pulls. Manual stretching exercises can increase the stretch tolerance of muscles and connective tissue, adapting them for the demands of sport.
A human athlete works to develop three major areas of physical fitness when training for sports participation--building muscle strength, increasing endurance, and improving flexibility. Horse trainers are conscious of the need to develop muscle strength and the cardiovascular system, but how often do they consider the need for flexibility in the horse?
Flexibility refers to the ability of soft tissue to relax and yield to stretch forces. (It might be more appropriate to call this extensibility.) Flexibility exercises are designed to increase range of motion or to maintain normal range of motion. Flexibility can be limited by bone structure or by soft tissues such as the muscles and their fascial sheaths, the joint capsule, or the tendons. Soft tissue stretching can bring about significant changes in joint mobility.
Besides being an important part of conditioning for sports participation, flexibility exercises are a necessary part of rehabilitation from injury. Prolonged stall rest or wearing a splint or cast results in shortening of the tissues around a joint. Trauma causes protective muscle splitting, which can result in muscle fiber shortening if allowed to persist. Muscle strength is lost when soft tissue adaptively shortens over time.1 The muscle is tight, yet functionally weak and no longer capable of strong or ballistic contraction.
A more severe condition results when scar tissue is laid down between otherwise normal muscle fibers and ties down the motion and function of the muscle. Chronic inflammation in the muscle can cause fibrotic adhesions to form throughout the musculature, reducing its contractility and extensibility.
Stretching For Pain Relief
Stretching exercises can be of great benefit in providing relief from pain arising from the muscles or the fascia. Fascial contracture occurs when muscles and their connective tissues tighten abnormally. Age, chilling, inactivity, and muscle strain cause contractures that put pressure on nerve pathways as they transverse through muscle. This abnormal pressure results in pain and limits the power the muscle would be capable of producing during work.
When muscles are stretched with consistently repeated exercises, some of the elongation achieved remains after the exercise is completed.2 The stretching exercises must be gradual and progressively more demanding. Gentle and progressive stretching relieves pressure on local nerves, thus reducing discomfort.
Stretching has a beneficial effect on post-exercise soreness. Muscle soreness that develops after strenuous exercise is composed of muscle spasm, edema formation, increased stiffness, and resistance to stretch. To reduce this performance-limiting soreness, one must inhibit muscle spasm, stimulate local circulation, and alter the function of the organs involved in the stretch reflex.
These organs include the Golgi tendon organ and the muscle spindle. These sensory structures are located within the muscle or at the musculo-tendinous junction. The Golgi tendon organ wraps around muscle fibers and is sensitive to the tension in a muscle caused by either stretch or contraction. The Golgi tendon organ protects the muscle from excess tension by causing the muscle to relax. The muscle spindle is sensitive to stretch and reacts protectively by causing the muscle to contract when it is in danger of over-stretching. A chronically irritated muscle spindle sets up a muscle trigger point--a source of muscle pain. Slow stretching increases metabolism in the muscle spindle, elevating its oxygen consumption and allowing it to relax. This reduces the trigger point. Slow stretching also makes the Golgi tendon organ inhibit tension in the muscle, allowing the muscle to lengthen.3 These structures provide the individual with kinesthetic sense, or an awareness of the body, and protection from extreme muscle activity.
A study using humans as subjects was designed to determine whether cold or heat therapy combined with stretching would elicit the greatest amount of muscle relaxation when post-exercise soreness was present.4 The use of cold and slow stretching--holding for 10 seconds at the end point of the stretch--was more effective in reducing delayed muscle pain. Apparently cold decreases the activity of the Golgi tendon organ, allowing the muscle to be stretched. Cold also causes a reduction in nerve conduction velocity, which would inhibit muscle spasm. This study indicates that when pain limits range of motion, specific controlled stretching exercises, especially if preceded by local cooling of the muscle, such as with ice cup massage, could reduce soreness.
Manual stretching provides the opportunity to assess the health of one's horse in a unique way. It is an opportunity to detect imbalances in flexibility and extensibility that could indicate the development of injury. Noting the resistance to gentle stretching maneuvers, the horse owner has a clue that the muscle involved is not being used to full capacity. Such an imbalance is a part of the chronic injury syndrome or could lead to an acute injury.
Stretching In Rehabilitation
Flexibility exercises should be started immediately after injury, as long as the exercises do not aggravate the injury. Stretching should be very gentle in the early stages and performed very slowly. Special attention should be paid to signs of discomfort in the horse's body language. It is most important to consult with a veterinarian before beginning any rehabilitation routine so that the extent and nature of the injury are known.
Stretching For Injury Prevention
Flexibility provides a certain amount of insurance against injury to the muscle and its tendon.5 Muscle fibers tear when heavy loads are placed on shortened, tight muscles. Using stretching exercises for injury prevention became popular with professional and college football teams many years ago. Football is a game of short bursts of effort with very little extension of the joints. Muscle strains and tears were very common, and still are common, although incidence of this type of injury has been significantly reduced with the advent of supplemental stretching programs, according to many athletic trainers.
Stretching For Efficiency Of Movement
The principles of physics and biomechanics have shown that the degree of stretch in a muscle prior to contraction will affect the strength of that contraction. A muscle will contract with maximum efficiency when it is stretched to 100% of its functional length. This is the reason for the various takeoff positions in track and field events. A typical conditioning routine for the equine involves muscle exertion at only about 60-75% of the maximum length as the horse is kept collected to keep his speed under control. Repeated workouts without the opportunity to extend the muscles to their maximum length can create muscle contractures and tightness. Research into the effects of stretching for soccer found that regular soccer training resulted in a decrease in range of motion.6 Flexibility was seen to improve and a reduction in the number of strains was noted when stretching exercises were added to the end of the warm-up.
A horse with great reach and rapid stride turnover certainly will cover ground more rapidly than his shorter-striding stablemate. This was a factor for the great Secretariat as he was going stride-for-stride with Riva Ridge, outdistancing him in three powerful strides in a famed performance in the Marlboro Cup. Secrtariat's reach was greater, allowing more power production per stride.
Certainly, muscles that have become contracted due to injury could benefit from gentle stretching exercises, but what about the apparently healthy horse? We often see horses stretching themselves in their stalls. A good roll in the dust can give the muscles of the torso a bit of a stretch. But historically horses are not the great stretchers of the animal kingdom. We observe our domesticated dogs and cats indulging in individual stretching routines, although they are allowed relatively more room to roam than a horse kept in a stall. Domestic cats and dogs are descendants of den dwellers, for whom a good stretch was essential preparation for subsequent activity.
The ancestors of today's highly regimented equine roamed the plains and forests freely, rarely staying in one spot long enough for the muscles to get stiff. Equids kept one nostril to the wind in order to stay ahead of their predators through continuous movement or short bursts of trotting. Horses which are passively stretched by their handlers soon learn to enjoy it and often are observed to stretch spontaneously more often.
When To Stretch
Stretching to improve flexibility is best done after a warm-up. Trying to stretch cold muscle could result in small tears in the muscle fibers. The muscles of a specific area can be warmed with a hot pack, electrical stimulation, or ultrasound, but a general warm-up of walking and slow trotting is most effective.
Have you ever noticed that your own muscles are especially inflexible in the morning? The body temperature is usually lower in the morning than at any other time of the day. Lowered body temperature decreases the ability of interstitial fluids to flow through muscles, tendons, and joints. Decreased flexibility in the muscles and tendons means less ease of movement in the joints. Lowered circulation in the morning allows for accumulation of products of inflammation from chronic overuse injuries. Human runners have learned to reduce morning stiffness by stretching after their workout. There is no proof that this will help horses, but it is food for thought and careful experimentation.
A mild muscle strain can be confused with post-exercise muscle soreness. A strained muscle is characterized by localized pain and swelling. It involves overstretching and tearing of muscle. Post-exercise soreness is more generalized discomfort that occurs when the activity level is increased and is thought to be due to microtrauma to the fascia and to muscle fibers. Gentle stretching helps one to distinguish between these two problems. Post-exercise soreness will decrease when the muscle is slowly and carefully stretched. A strained muscle will become more painful upon stretching. Muscle strains should be iced immediately and rested, but post-exercise soreness benefits from mild exercise such as walking and stretching.
Whether exercise is taking place in the winter or in the summer, do not underestimate the value of walking. Include longer bouts of walking before exercise in cold weather to enhance blood flow through the muscles. Blood flow increases muscle temperature and oxygenation of the muscle cells, facilitating muscle function.
Walking for extended periods before athletic exercise will improve oxygen delivery and waste product removal. The muscle fibers recruited at the walk are mostly slow twitch fibers. These fibers rely on oxygen from the blood for fuel so muscle capillaries dilate in response to their activity, benefiting the entire muscle. Brief, intense exercise will not raise cooled muscle temperature as it is done by fast twitch fibers that utilize anaerobic metabolism.
Tips For Safe Stretching
There are several important things to keep in mind as you work to improve your horse's flexibility. Stretching should be done in a relaxed, easy manner. The limb is guided through a range of motion, held in that position briefly, then gently returned to the original position. Do not pull on the horse's limbs. Disregard what you hear in the gym about stretching to the point of pain. Overstretching produces microscopic tears in the tissues that can lead to scarring and the eventual loss of elasticity, the opposite of your goal.
A certain amount of sensitivity is necessary to carry out a successful stretching program. The stretch should be done slowly until a slight amount of tightness is felt. Human athletes work up to holding the stretch for 30 seconds. No research has been done to indicate how long a stretch should be held with a horse, so it is up to you to be aware of what he is feeling. Human athletes repeat each stretching maneuver several times for the best results. Be aware of your horse's comfort level before repeating the exercise. Ignorance and lack of attention to task will be the downfall of an effective stretching program.
Never use a bouncing or jerky stretch. When a bouncing movement (called ballistic stretching) is used, the muscle responds by tightening to protect itself from overstretch. The muscle spindle is activated when the muscle is overstretched, producing a protective tightening. You will be working against the muscle with a bouncing stretch, increasing the likelihood of microtrauma.
Never stretch an acutely torn muscle. Allow time for it to heal before a rehabilitative program is begun. Your veterinarian can advise you on this.
Avoid excessive traction and pressure on the joints. Avoid movements that twist the joints.
Do not attempt to gain full range of motion in one or two sessions. Increasing flexibility is a slow and gradual process. It might take several weeks to see significant progress.
Be aware of the normal range of motion in the horse's joints. A joint should never be forced beyond its normal range.
1. Kisner, C and Colby, LA. Therapeutic Exercise Foundations and Techniques. 2nd ed. FA Davis:1990.p.109.
2. Morehouse, LE and Miller, AT. Physiology of Exercise. 6th ed. CV Mosby:1971. p.73.
3. Kisner. p. 114.
4. Prentice, WE. An Electromyographic Analysis of the Effectiveness of Heat or Cold and Stretching for Inducing Relaxation in Injured Muscle. J of Ortho Spts Phys Ther. 3:1982.133-140.
5. Klafs, CE and Arnheim, DD. Modern Principles of Athletic Training. 4th ed. CV Mosby:1977. p.37.
6. Moller, MHL et al. Stretching Exercises and Soccer: Effect of Stretching on Range of Motion in the Lower Extremity in Connection with Soccer Training. Intl J Sports Med. 6:1985. 50-52.
About the Author
Mimi Porter lives in Lexington, Ky., where she has practiced equine therapy since 1982. Prior to that, she spent 10 years as an athletic trainer at the University of Kentucky. Porter authored The New Equine Sports Therapy, published by Eclipse Press and available at www.exclusivelyequine.com or by calling 800/582-5604.
POLL: University Equine Hospitals