It can cause you more double barreled misery than any other part of your body. I am your backbone, and you have pretty wild ideas about me. You think of me as a series of “joints” that go “out” out where? I ask. Every year or so, when I are up, you have me pummeled, heated and drugged, none of which das much good. e pains I give you are simply my response to the bad treatment you give me. Ironically there is very little wrong with me that you could not x yourself. You need never have another backache. Trouble in my department began when your ancestors decided to stand erect. Instead of a nicely balanced suspension bridge, I became a tent pole. And quite a versatile tent pole at that one that can bend, twist, swivel a head and support most of the body’s weight.
I also must provide security for your 45 centimeter spinal cord. Let anything serious happen to this whitish, one centimeter-thick cable and you will likely spend the rest of your life in a wheelchair, for the millions of messages which y back and forth along it direct all your activities below the neck level. I protect your cord with three layers of sheathing, a uid bath to take up shock, plus a bay housing. irty one pairs of nerves branch out from the cord. Almost half are sensory, which convey information to the brain; the rest are motor, which transmit orders from the brain to the muscles.
In some situations, the cord even does its own thinking. Your finger touches a hot stove. ere is no time to waste conveying this information to the brain. My cord orders a re ex action and the nger is jerked away. e chances of my cord ever causing you any trouble are rather remote. But my 33 vertebrae and their supporting structures are another story. A wide range of things can cause pain them: trouble with kidneys, prostate or liver; arthritis and various infections; even emotions. For example, several times you have had big worries that nagged at you for days. You developed a dull backache. You did not connect my hurting with your worries. As usual, you thought I was “out.” What was really happening was this: strong emotions tighten muscles; mildly tensed for several days, my muscles simply grew tired and announced it with dull pain. Once you stopped worrying. I ceased hurting. If you would study my structure really an engineering marvel, you would get a better idea of what causes backache.
Starting at the top, I have seven cervical vertebrae, which are capable of an extraordinary range of movement. In addition to support your head, they can twist to let you look down at the ground or up at the stars. Laterally, they permit 180 degrees of motion, letting you look over either shoulder. e 12 thoracic or chest vertebrae, which come next, are not capable of such a wide range of movement; there is no need for it. e ribs are hooked to these. Trouble in this area is rare. At the lower end are ve heavy lumbar vertebrae, which carry most of your weight; ve sacral segments, which are fused together to form the coccyx, all that is left of the tail once sported by your forebears. is lowers area, particularly around the fourth and fth lumbar vertebrae, is the big trouble spot.
When you were born, I was more or less straight. en, when you began to hold your head erect, my vertebrae took on a curve in the neck area. Another curve developed lower down when you began to toddle. Result I have a vague S shape today. Actually, this is far better than a perfectly straight spine, for the arches act as shock absorbers. ere are other shocks absorbers as well there have to be. If vertebra ground on vertebra, absorbing 100 pound jolts with every step you take, I would not last long. us, between each pair of vertebrae, I am equipped with cushions called dim.
Something like jelly doughnuts, they have a tough envelope of cartilage containing a resilient, jellylike interior substance. You attribute your occasional back trouble to something you call a “slipped disc.” you are wrong. You have never had one. But since you are becoming a candidate for this type of trouble, you may as well know about it. Discs are susceptible to several kinds of injury. A really severe jolt an auto accident, a serious fall can simply squash a disc, usually one at the bottom of the spine. is often calls for major surgery involving removal of the remnants of the disc and fusion of the two vertebrae. A less severe injury can rupture the disc’s tough envelope, permitting the enclosed jelly to ooze out. is can cause acute misery. e disc material presses on a nerve, and the irritated nerve throws one of my muscles into spasm. is spasm is a protective e ort. e muscle senses that I am in trouble and tries to splint me to prevent motion that might cause additional damage.
Muscles in spasm have other e ects as well. ey twist the victim out of shape, giving him a list and possibly bending him forward. Almost always a ruptured disc irritates the sciatic nerve, which extends to the legs. Pain then radiates all the way down to the toes. Your back troubles, as with most people, stem from weakness and stretching in my elaborate supporting system 400 muscles and 1000 ligaments. You would be surprised to know what poor shape my muscles are in. You think your Sunday golf keeps you in you. It
does not. Look at a few of the burdens you thrusts on me. You are beginning to spout a paunch about four extra kilos. Because your abdominal muscles have been getting weaker for some time, my back muscles must carry this additional load. (Incidentally, that is why your wife got a backache with each pregnancy from that extra load up front).