Try listing the names of ten adult friends at random. If seven of them are backache victims, and only three are free of the sufferings addressed in this book, they're a set of typical persons. If you are one of the seven unfortunates (and the fact that you're opening this book means you probably are), the problem becomes acutely personal in terms of pain and inconvenience. However, the probabilities are that if this is a new backache, you will be just fine within the next four to five weeks.
In any case, you're not alone. In the Western world, epidemiological studies reveal that back pain afflicts a staggering sixty to eighty percent of the population. Out of every ten people under forty-five who have chronic medical conditions limiting their activities, four are back and spine pain victims. Backache takes a backseat only to headache as the most common medical complaint, and is second only to the common cold as a reason for missed work. In fact, absence from the workplace due to disabling back pain has soared.
There was a fourteen-fold increase in the prevalence of low back pain in the United States between 1970 and 1981, and even more of an increase in England and Sweden. Unfortunately, five percent of the population will complain of low back pain in a given year. Furthermore, sciatica, pain in the leg, may be associated with back pain. It is known that forty percent of all adults will have sciatica at some point in their lives.
A sore back becomes even more sobering when you realize how often it can become chronic, debilitating, and life-diminishing. If you're laboring under a difficult back, you don't have to be reminded of this -- but consider: If you're a worker who is absent from work for more than six months with a bad back, statistics show you have only a fifty percent chance of ever regaining full productivity. After a year, your chances dip to twenty-five percent. Add the high cost of treatment and you have a more graphic portrait of the social and financial sufferings involved. The average bad-back episode will run you $4,300, and the diagnosis and treatment of backaches in the United States costs $5 billion every year. If we count up loss of productivity, cost of disability payments, Workmen's Compensation, and lawsuits, the figure soars to about $14 billion. You should not leave this pessimistic paragraph without being reassured that over eighty-five percent of people with an acute backache will be over it in a month's time.
Here's one more way you can grasp the magnitude of the financial problem. The U.S. Postal Service is one of the largest employers in the country. There was a time when we paid 20¢ for a first-class postage stamp. Guess how much of that 20¢ was applied to the medical care, compensation, and related expenses of postal employees with backache? About five percent -- 0.9¢ -- nearly one cent!
The purpose of dragging in statistics like these is not to depress you, but rather to convince you, if you need convincing, that back pain is a major social problem. What cannot be expressed in numbers, although it is of equal or greater importance, is the profound human suffering and compromise in quality of life that the back pain sufferer experiences.
The question that may occur to you at this point is, why? Why is the human back such a vulnerable, annoying, and frequently painful part of the anatomy? Has it always been thus? Certainly the spine has been a preoccupation for centuries -- as attested to by sayings such as "He's a spineless person" and "She really has her back up about it," or "He's got a yellow streak down his back" and "She's carrying the team on her back." Shakespeare aficionados will recall the insinuating words of Iago, who whispers to Desdemona's father: "Your daughter and the Moor [Othello] are now making the beast with two backs" -- Elizabethan jargon for "having sex." Perhaps echoing the Elizabethans, Jamaican men complaining of impotence will say they have lost the strength of their backs. Treachery, we know, is conveyed as a "stab in the back," and paranoia in the phrase "They're laughing behind my back." We could go on cataloguing spinal expressions in art and life, but if you're lying on a painful back or "with your back against the wall" you'll probably want to get to the treatment/prevention chapter pretty quickly.
Some researchers have reflected that we humans have only recently evolved into two-legged creatures, and that staying on all fours might have saved us from backaches. There are several problems with this theory. One is that the treatment implied, reversion to four-legged locomotion, would require some radical life-style changes, perhaps driving shoemakers out of business or placing undue market demands on glove and knee-pad manufacturers. Besides, animals have back pain too; they just don't complain about it. Most important, the hypothesis doesn't fit the anatomic and evolutionary facts: Our spines are perfectly suited to an upright stance and don't differ significantly from those of our hominid ancestors. Finally, even though there are sexual problems associated with backache (Chapter VIII), back problems could not play a part in the process of evolution because the genes can be readily passed on well before the onset of backache, which is usually in one's thirties.
If we are to look for reasons, we'd do better to examine the quality of our lives -- especially what we do with our backs. Frankly, even an extensive analysis of all the data does not provide a simple, clear answer. Nevertheless, you will certainly get a better understanding, so read on!
WHO'S AT RISK?
Of course, if you're a backache sufferer, your interest in this book is more apt to be personal than sociological. How do the back statistics apply to you? What category of back sufferer do you fall into? What are your risks -- and how can you reduce them? One of the goals of this book is to provide this information, along with specific recommendations for managing your back on the job and at home. The following facts, gathered from epidemiological studies, can help you calculate your risks -- for we now know that sex, age, occupation, leisure activities, and life-style all influence the state of your back.
Back pain patients tend to be between thirty and fifty-five years old. Why? Very simply, the discs between the vertebrae of your lower back change in the normal course of aging. The young disc is elastic and full of fluid, but starting at about age thirty, it gradually becomes dry or scarred and its mechanics change, making it more likely to fragment, move out of place, or cause pain. This is analogous to a jelly doughnut. When it's fresh, the pastry is pliable, resilient, and the center contains jelly. As it ages, the outer portion hardens, becomes more brittle, cracks, and flakes. The jelly in the middle dries out.
The puzzle, however, is that while all discs undergo this transformation, not all cause pain -- and certainly all do not herniate.
Actually, back-pain risk decreases for men after age fifty, but this is not so for women. This is because the problem of osteoporosis begins to occur in women and causes backache. In the next section, gender-related issues in low back pain are discussed.
Epidemiological studies suggest that males are slightly more prone to herniated discs (this is a situation in which a part of the disc moves out from its normal position between the vertebral bodies, causing severe back and/or leg pain) and more likely to undergo surgery than females with problems of equal severity. Perhaps differences in occupation, athletics, and amount of driving, rather than genetics, account for the male's greater weakness. Or perhaps men simply tolerate pain badly and are thus more afflicted and therefore more likely to end up with the most rigorous treatment.
On the female side, elderly women are at highest risk for osteoporosis, a loss of bone density that weakens the vertebrae and sometimes causes them to collapse. The relative risks are even greater (3:1) for a woman who has had more than two full-term pregnancies. Hormonal changes after menopause are thought responsible, and there is evidence that estrogen-replacement therapy -- together with adequate vitamin D and sunlight, dietary calcium, vigorous physical activity, and exposure to fluorides -- can be of help in the treatment of osteoporosis.
Full-term pregnancy is notoriously hard on the lower back. For one thing, it brings with it mechanical problems, such as increased weight and a protruding abdomen, that combine to shift the mother-to-be's center of gravity forward and put stress on her back. But, perhaps more to the point, a hormone called relaxin, produced during the later stages of pregnancy, can cause the ligaments in the pelvis and lumbar spine to relax, undermining the back's mechanical strength. After her child is born and requires trips to an appropriate changing table and so on, the new mother should learn the proper biomechanics of lifting, described in Chapter II.
There is also a type of arthritis of the lumbar spine (low back) associated with an abnormal forward displacement of the vertebra (degenerative spondylolisthesis), which is four times more common in women than in men. Sorry folks, but the reason for this remains to be discovered.
One kind of back problem, intervertebral disc disease (see Chapter III), seems to run in families. Ditto for slipped vertebrae, the almost unpronounceable name of which is spondylolisthesis (SPON-dil-low-la-THEE-sis).
A few racial differences show up here. American whites, for example, are more prone to spondylolisthesis than American blacks -- and Eskimos have about a ten times greater tendency to develop the disease than whites. The basis of this seems to be an anatomic difference in the lower part of the lumbar spine.
There is evidence that herniated disc problems "run in families." There may be a hereditary predisposition in the chemical makeup of the disc that makes it more likely to fragment and move out of its normal anatomic position and cause nerve irritation.
You can't do very much about your sex, age, or race, but you can change your job, or some of its tasks, when necessary -- which is fortunate, since your job may affect your back more than anything else.
People who spend at least half their job time driving a motor vehicle are three times more likely than the average worker to suffer a herniated disc. This fact has some cogent and interesting associated observations. A key issue here is that of road vibrations. Most vehicles vibrate in a range of 4.5 to 5.0 Hz (cycles per second). The first resonant frequency (that frequency likely to cause perturbation or damage) of our spines is in the same range. Laboratory tests have shown that vibrating the spine at this frequency range can damage the spine and cause disc herniation. Vibration in this range has also been shown experimentally to increase the production of pain-causing substances. To put it simply, most cars, buses, and trucks vibrate at 4.5 to 5.0 cycles per second, and this is a range that can damage the spine and cause back pain and disc herniation. The reader should know that some Swedish and Japanese cars do not vibrate at 4.5 to 5.0 cycles per second.
Sedentary occupations in general are bad news for your back, as sitting puts great pressure on the disc between the vertebrae. When it comes to driving, then, we have prolonged sitting without changing position and -- what is probably more important -- a spine constantly jarred by vibrations. Cabbies, truck drivers, bus drivers, train conductors, beware: Your job could be hazardous to your back. Chapter VI will give you some advice that should help you, should you be one of these at-risk people.
It takes about five years for sedentary occupations or damaging leisure pursuits to do their evil work on your back. Weekend sitting, for example, has been linked to herniated disc disease in males, a fact that football widows may find useful ammunition. Obviously, most office jobs fall into the sedentary category -- so secretaries, accountants, lawyers, academicians, computer programmers, and middle managers alike would do well to change position, stand, walk to appointments, and relax from time to time.
However, if you get off your backside to spare your back, don't turn around and lift your typewriter, either. Jobs involving heavy lifting, pulling, or carrying probably lead to lumbar disc disease. Sudden unexpected bouts of lifting, as when you're helping a friend move his piano and he lets go, appear to be followed by complaints of acute back pain in doctors' offices. Certainly in heavy-labor jobs, the weight lifted, frequency of lifting, improper lifting, and body mechanics all go hand in hand with low back pain. Is it any coincidence that heavy-industrial workers, farmers, and nurses and nurse's aides are more often afflicted with bad backs than most of us? On the basis of my experience, I'd also have to put firemen, policemen, and emergency medical technicians, who must perform extensive lifting quickly and without proper positioning, in the high-risk class.
Another note: Twisting injuries are often blamed for back pain and disc damage, and future occupational studies should consider this.
One noteworthy condition that appears to be an occupational hazard is degenerative disc disease of the lumbar spine. The term is unfortunate, as it sounds as though we were moldering away and falling apart inside. Actually, lumbar disc degeneration is probably little more than normal wear changes in the spine. On the X ray, the doctor sees a narrowed disc space and some osteophyte (bony outgrowth or spur) formation. As people age, these changes tend to show up on the X rays of half of all women and about seventy percent of the men -- but mechanical stress does appear to hasten the process. Miners, dockworkers, and outdoor laborers such as farmers and road workers are at risk, while sedentary workers appear not to be.
A similar problem is arthritis of the facet joints. See figures 2-2, 3-5, and 3-9 to understand facets, facet joints, and facet joint capsules. Two facets go together, alone with a capsule, to form a facet joint. Arthritis of the facet joints is a condition that can come on with age, though it can occur independently of degenerative disc changes. Degenerative changes in the facet joints are frequently observed in miners and even more frequently in obese people.
In summary, here's how Dr. Gunnar Anderson of Sweden has mapped out the occupational danger signals for your back:
* Physically heavy work
* Static work postures
* Frequent bending and twisting
* Lifting and forceful movements
* Repetitive work (such as assembly-line occupations)
In Chapter V, you'll learn how to minimize the wear and tear on your back at home and on the job.
Back in the sixties, we doctors cared for a number of patients who complained of back pain associated with a new dance craze called the twist. To a rock and roll beat of Chubby Checker and others, the twist dancer held his upper torso relatively fixed while rotating the pelvis as vigorously as possible about the long axis of the body. Nowadays, twist injuries are as rare as smallpox, though one wonders about the effects of Saturday Night Fever gyrations, break dancing, dirty dancing, and acrobatics on the lumbar spine.
In a more sober vein, some studies have linked the tendency to report sick from work to lower educational level, lower intelligence, and lower socioeconomic status. Workers with a low sense of self-importance or those who describe their jobs as boring, dissatisfying, and repetitious are also more apt to stay in bed with backaches. These fellow humans should not be patronized, but must be treated with compassion and careful attention to the quality of their work life. Of course, pain can be a signal of depression. The onset of back pain can also be related to life situational stresses, such as a promotion, a vacation, an honor, the loss of a friend, mate, or a job, or the necessity to move. Recently, psychiatrists have been reporting that a sadomasochistic patient may complain of spine pain in the hopes of obtaining a surgical procedure. Like the notorious "Munchausen's syndrome" patient, who seeks and achieves a collection of abdominal scars, these patients are usually found to be free of disease when their backs are needlessly opened up.
Cultural factors play a role in back pain, or lack of it. Backache appears to be far less common in cultures in which the squatting position is common. Squatting curves the spine into a slightly flexed position, in contrast to the Western mode of standing and sitting, where the spine curves in the opposite, slightly extended direction. One study comparing X rays of individuals from a squatting culture with those from a sitting culture noted less evidence of disc degeneration in those from the squatting culture. A second theory is that people in developing countries are less prone to back problems because they work harder, walk more, and are less sedentary generally. Still, evidence for both theories remains meager, but thought provoking.
Body Build and Posture
"For heaven's sake, stand up straight, or you'll get a bad back!" your parents may have innocently instructed you. Well, parental dogmas notwithstanding, most studies maintain that there is no real connection between voluntary posture and back pain. A flat back and a slumped back are equal in the eyes of the spine. Moderate scoliosis, or sideways curvature of the spine, is probably unrelated to back pain, though severe lumbar lateral (sideways) curvature probably is hard on your back.
An interesting study allowed by an outdated tradition helps to prove this point. In certain women's colleges in the Eastern United States, posture was carefully evaluated, to the point of obtaining standing nude photographs to permit an unencumbered evaluation of posture. A careful study of these pictures of the classes of 1957, 1958, and 1959, and a review of the department of physical education's written evaluation, dictated the following conclusion: Posture, neither good nor bad, was in any way associated with a higher or lower incidence of low back pain over a twenty-five-year period.
Also contrary to folklore, moderate differences -- as much as three-fourths of one inch -- in leg length are inconsequential to your back.
As for body build, most studies support the contention that there's no strong correlation between height, weight, body build, and backache. Yet, all researchers can't agree all of the time: A few studies have shown a tendency for tall and obese people to develop backache.
A Vermont study turned up the unexpected fact that people with chronic coughs and bronchitis frequently suffer from herniated disc disease, and now more recent research has implicated cigarette smoking in disc disease. Here is yet another health negative for smokers. There is pretty good evidence that nicotine interferes with the blood flow to the vertebral body and around the disc. This may cause abnormalities in the normal biological functions of the disc, as well as back pain.
The size and shape of your spinal canal may predispose you to develop sciatica (leg pain and weakness that may or may not be associated with back pain). When the canal is small or trefoil-shaped, the nerves that can cause sciatica are more easily irritated.
Perhaps you've concluded, after perusing the last few pages, that the most likely candidate for back pain is a socially maladjusted male truck driver who is tall and does a lot of loading and unloading during a working day. So much the worse for him if he has a family history of low back pain, is divorced, drinks and smokes to excess, and belongs to a lower socioeconomic stratum. If he isn't particularly proud of his work, and spends his weekends vegetating in front of the TV, give him up as a hopeless back pain invalid! Well, this sort of composite portrait is an improper use of statistics, of course, since each individual defies easy categorization. Many a TV-addicted, sedentary, depressed truck driver has never had a backache in his life. Of course, this characterization is presented to emphasize some points. I certainly mean no disrespect to these frequently helpful and lifesaving fellow humans of the highways.
Yet all of the life-style factors we've mentioned can translate themselves into an aching back, and it's best to start with a good, hard look at yourself and your life. Don't despair: Soon we'll tell you what you can do for your back.
Copyright © 1983, 1990 by augustus A. White III, M.D.