In this excerpt from his book The Rider’s Pain-Free Back, retired neurosurgeon and horseman Dr. James Warson explains why eventers can be prone to back pain.
To persons who are not jumping enthusiasts, falls are the most obvious source of injuries in a sport that involves aiming a galloping horse at an immovable fence. While it’s true that falling, due to a refusal or some other error in judgment, can inflict significant trauma on a rider’s back, hunter, jumper, and event riders also tend to suffer a number of injuries as a result of the normal demands of their discipline.
Because of the huge forces involved in launching a 1,200-pound horse over an obstacle of any size, it is common for hunter, jumper, and event riders to experience the hyperflexion and hyperextension of whiplash, muscle spasms, and disc damage if they misjudge a distance. As a result of the inevitable concussive forces they experience, hunter, jumper, and event riders tend to accentuate wear and tear on the facet joints of their spine. (Bareback or saddle bronc riders also very commonly have huge facet joints. The joints have been slammed against each other and compressed so many times that they have endured a sort of chronic irritation. As a result, they have produced giant, hypertrophic, or enlarged facet joints.) Over time, riders who jump also gradually stretch, and thereby loosen, the anterior longitudinal ligaments of the spine. Damaged ligaments and weakened discs—most often in the cervical (neck) and lumbar (lower back) regions—are commonly found.
Common Causes of Back Pain
The muscles themselves have pain receptors within them. These are triggered when a particular muscle is stretched, pulled, hit, or injured.
The most common cause of back pain is simply a muscular strain or pull in a person who is in relatively poor condition. The so-called “weekend warrior” who has been indoors all winter, who gets out the first good day of spring to ride, do some gardening, or do some heavy lawn work, is a prime candidate for a strained muscle. People will very commonly overextend the capability of back muscles that have not been properly strengthened and develop significant back pain as a result.
A bulging disc may be responsible for irritating or compressing the nerves of the spinal canal. The nucleus of the disc does not have any innervation. It causes pain only when it bulges or ruptures through the wall of the disc and strikes a nerve that runs behind the wall. Nerves may also be irritated if they come into contact with one of the arthritic or spondylitic ridges that have formed on the vertebrae.
Another cause of nerve irritation occurs when the facet joints overgrow as a result of the laying down of bone due to chronic irritation and trauma. This is especially common in people that experience violent back extension, as can be the case in jumping.
The disc wall itself has nerve fibers in it. Sometimes when the disc is bulging, the patient can actually feel it stretch. A stretching, or bulging disc generally feels like a midline, aching back pain.
Like the nucleus of the disc, bone itself also doesn’t have any pain fibers within it. However, bone is covered with a lining called the periosteum that has pain fibers in it. If you fracture a bone and bleed under the periosteum, it will separate from the bone and will be quite painful.
This excerpt from The Rider’s Pain-Free Back by Dr. James Warson is reprinted with permission from Trafalgar Square Books (www.horseandriderbooks.com).