Alice’s 12-year-old Thoroughbred gelding, Mr. Red, had become very resistant to the right, especially at the canter.

He was refusing to bend his body in that direction and when moving, his pelvis rotated to the right and his hip bone dropped lower on that side. Both shoulders, particularly his left, showed restriction of movement. To make matters worse, Mr. Red was becoming more flighty and easily upset. Though skeptical, Alice decided to follow her trainer’s advice and seek chiropractic help.

Examination revealed significant chiropractic and associated muscle problems in many parts of Mr. Red’s body, including his jaws, wither area, sacrum and pelvis. I also observed that he landed much harder on his left hind than his right.

Red’s treatment consisted of chiropractic manipulation and muscle work. Over the next few days he started moving evenly behind and his range of pelvic motion increased. The pain and muscle spasms in his left shoulder and right hip disappeared. Alice could not believe the change in his overall attitude. He became more calm and quiet than she had ever seen him; yet he was forward and willing and showed no resistance to his right lead. Mr. Red had gotten his name because of his chestnut color and because, during the two and a half years that Alice owned him, he constantly moved his mouth like the talking horse, Mr. Ed, of television fame. Though it was very cute, it may well have been associated with discomfort since he stopped the constant “talking” motions with his mouth after his treatment. When I saw Red two weeks later he required only minor follow up chiropractic and muscle work. He is next scheduled to be seen in three months.

While many people like Alice have witnessed the benefits of chiropractic, particularly over the last decade, it remains one of the most controversial of complementary or integrative health care treatments. There are simply so many misunderstandings about what it is and how it works. So let’s clear up some of the issues.

What does chiropractic do?

Let’s start by looking at two misconceptions. Do chiropractors put bones (especially vertebrae) back in place? The answer is no. If bones are truly out of place – that is, there is a dislocation or even a partial dislocation (known as a medical subluxation) – it’s a job for a surgeon. This brings forth the second misconception, that nerves are being pinched. If the bones are not dislocated, or medically subluxated, the nerves are not going to be pinched unless there are enough degenerative arthritic changes in the facet joints to cause impingement. It is the inflammation around the nerve that gives rise to the misconception that the nerve is pinched.

So, what does chiropractic, sometimes referred to as “musculoskeletal manipulation,” actually do? Properly performed chiropractic “adjustments” return vertebral joints to their normal and full range of motion. Restoring normal range of motion (ROM) allows information from the body to flow unimpeded along nerve pathways to the central nervous system (CNS). An appropriate neural response can then be sent outward to the body’s muscles, organs and tissues.

Getting the message

If there is lack of motion within a vertebral joint, an inflammatory response occurs around the nerve root. This limits the transmission of impulses into the spinal column (spinal nerve tracts), which carries messages to the brain. If the brain doesn’t get the messages clearly, it cannot respond by sending an appropriate neural response back through the system and out of the vertebral nerves to the body.

Joint surfaces and the tissues that support the vertebrae are richly supplied with “receptors” that transmit information to the CNS (spinal cord, brainstem and brain). Various forms of receptor are sensitive to temperature, pressure, mechanical forces, chemical mediators and pain. The act of “adjusting”, which involves moving the vertebral joint a n appropriate amount, recruits and activates thousands of additional receptors, thereby strengthening and enhancing the signal. The signal is now intense enough to force its way across the “inflammatory barrier” set up by the immobilized vertebrae, allowing a clear message to be sent to the central nervous system.

Essentially every cell in the body operates via an electrical signal either through ion exchange or by nerve impulses. All skeletal muscles work through an appropriate nerve signal. Bones, tendons, and joints can only do what the muscles tell them to do. Think what this means just to the act of walking, never mind the more advanced locomotion required in athletic performance. To create balanced and functional movement, the nerve supply to the muscles must be clearly received and acted upon by the central nervous system.

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Range of motion

To understand what happens when there is a vertebral joint immobility and inflammatory response, turn your head to one side. You will find it comfortably moves a certain distance. This zone of turning is called “active range of motion”. If you have a chiropractic issue in one or more neck (cervical) vertebral joints, you will likely find that you (or your horse) are not able to turn your head as much in one direction as the other (at least not comfortably). Now, gently push on your chin so that your head turns several more degrees. This is referred to as the “passive range of motion.” Your turning ended at a point called the “elastic barrier”; said another way, the vertebrae of the neck have been “brought to a state of tension”.

During a chiropractic adjustment, the vertebra is brought to this “state of tension” and then quickly pushed slightly beyond the “elastic barrier” into what is termed “para-physiologic space.” It is this movement that recruits and activates the thousands of receptors that strengthen the signals to the CNS. (It’s similar to hooking up jumper cables to a car battery. The cables provide a strong burst of energy to the battery, giving it enough electrical energy to provide “juice” for the starter to operate properly.)

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Adjusting your horse

How can you adjust something as large as a horse? The answer is you don’t. A chiropractor adjusts a single vertebra at a time, and often just one particular pair of facet joints on a pair of vertebrae. (There is a pair of facets at the front and a pair at the back that forms a joint with the vertebra ahead or behind). These joint surfaces are relatively flat and about the size of a thumbnail. Try this. Take two coins and lay one on top of the other with one edge protruding. Sharply tap one over the other, along the plane of contact between the two coins. You’ll find it takes very little force or strength to move the coin. So the secret in chiropractic is to carefully examine and determine which vertebrae are not moving freely through their range of motion (the distance one should be able to traverse over the other) and make the adjustment.

Increased speed exponentially reduces the strength required. For example, it is the acceleration of a hammer’s head that drives a nail into a board. The hammer cannot push the nail with its mass alone unless you swing it (increase speed). In other words, if you put the head of the hammer on the nail and push with all your might you cannot drive the nail into the wood. When you swing the hammer, the nail is driven in with ease.

The direction of the adjusting thrust must follow the direction of the joint surfaces. This is very important. The person doing chiropractic must understand anatomy and the biomechanics of movement of every vertebra in the body in order to safely and accurately perform an adjustment. That means an intense course of study and experience that is cumulative over time. If the person doing the manipulation is not properly trained and skilled, and applies too much force, the horse can be injured.

If the adjustment is carried out with too much force, the joint will be carried beyond the end of para-physiologic space and into or through the “anatomical barrier.” This will damage the tissues that support the vertebrae and result in pain and further dysfunction.

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When is chiropractic necessary?

In conventional veterinary and human medicine, one usually waits until there is lameness or disease and then provides treatment. In contrast, chiropractic therapy and other modalities such as acupuncture and massage are often able to identify pathology before there are overt symptoms. This stage of pathology is called “asymptomatic dysfunction.” It gives the caring and discerning rider an opportunity to keep the horse comfortable and at peak performance instead of waiting for a problem to manifest before providing treatment. A chiropractic maintenance program is the answer.

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The more work your horse does, and the harder it is, the greater the risk of injury. An athlete who is trying to sit on the “knife’s edge” just below peak may suddenly exceed that peak and incur an injury. Maintenance evaluation holds the promise of fewer injuries and better performance.

During the height of competition season, I recommend an evaluation on a monthly basis. During “off” seasons, or for horses that do lighter work, an evaluation every three, four or even six months may suffice.

With regular examination and a good maintenance program, chiropractic can help keep your equine partner sound and prevent injuries. A skilled and experienced chiropractor will work to restore your horse’s normal range of motion, allowing him to perform at his very best!


Dr. Kerry Ridgway graduated from Colorado State University in 1964 and was a founding member of the Association for Equine Sports Medicine. After practicing conventional medicine for over 20 years, he decided to direct his focus toward acupuncture. He bec ame certified through the International Veterinary Acupuncture Society (IVAS) and the American Veterinary Chiropractic Association (AV CA). Kerry and his wife, Christine, operate the EquiSport Center for Therapeutic Options, an equine sports medicine rehabilitation practice base d on acupuncture, chiropractic, and physical therapy modalities. Call 803-643-9188.

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