Muscle Cramps : When we use the muscles that can voluntarily be controlled, such as those of our arms and legs, they alternately contract and relax as we move our limbs. Muscles that support our head, neck, and trunk contract similarly in a synchronized fashion to maintain our posture. A muscle (or even a few fibers of a muscle) that involuntarily (without consciously willing it) contracts is called a "spasm." If the spasm is forceful and sustained, it becomes a cramp. A muscle cramp is thus defined as an involuntarily and forcibly contracted muscle that does not relax. Muscle cramps can last anywhere from a few seconds to a quarter of an hour, and occasionally longer. It is not uncommon for a cramp to recur multiple times until it finally goes away. The cramp may involve a part of a muscle, the entire muscle, or several muscles that usually act together, such as those that flex adjacent fingers. Some cramps involve the simultaneous contraction of muscles that ordinarily move body parts in opposite directions. Cramps are extremely common. Almost everyone experiences a cramp at some time in their life. Cramps are common in adults and become increasingly frequent with aging. However, children also experience cramps. Any of the muscles that are under our voluntary control (skeletal muscles) can cramp. Cramps of the extremities, especially the legs and feet, and most particularly the calf (the classic "charley horse"), are very common. Involuntary muscles of the various organs (uterus, blood vessel wall, intestinal tract, bile and urine passages, bronchial tree, etc.) are also subject to cramps. Cramps of the involuntary muscles will not be further considered in this review. This article focuses on cramps of skeletal muscle.

How can muscle cramps be prevented : Activity. For cramps that are caused by vigorous physical activity, authorities recommend stretching before and after the activity, along with an adequate warm-up and cool down. Good hydration before, during, and after the activity is important, as well as replacement of lost electrolytes (especially sodium and potassium, which are major components of perspiration). Excessive fatigue, especially in warm weather, should be avoided. Pregnancy. Supplemental calcium and magnesium have each been shown to help prevent cramps associated with pregnancy. An adequate intake of both of these minerals during pregnancy is important for this and other reasons, but supervision by a qualified health professional is essential. Dystonic cramps. Cramps that are induced by repetitive non- vigorous activities can sometimes be prevented or minimized by careful attention to ergonomic factors such as wrist supports, avoiding high heels, adjusting chair position, activity breaks, and using comfortable positions and equipment while performing the activity. Learning to avoid excessive tension while executing problem activities can help. However, cramps can remain very troublesome for activities that are difficult to modify, such as playing a musical instrument. Rest Cramps. Night cramps and other rest cramps can often be prevented by regular stretching exercises, particularly if done before going to bed. Even the simple calf stretching maneuver (described in the first paragraph of the section on treatment), if held for 10 to 15 seconds, and repeated two or three times just before going to bed will often be a great help in preventing cramps, usually within a week or two. The maneuver can be repeated each time the person gets up to go to the bathroom during the night, and also during the day once or twice. It may also help to avoid flexing the foot and pointing one's toes while in bed. If nocturnal leg cramps are severe and recurrent, a foot board allows the sufferer to simulate walking even while recumbent, and may prevent awkward positioning of the feet during sleep. Another important aspect of prevention of night cramps is adequate calcium and magnesium. Blood levels may not be sufficiently sensitive to accurately reflect what is actually happening at the tissue surfaces where the hyperexcitability of the nerve is occurs. Calcium intake of at least 1 gram daily is reasonable, and 1.5 grams may be appropriate, particularly for women with osteoporosis. An extra dose of calcium at bedtime may help prevent cramps. Supplemental magnesium may be very beneficial for some, particularly if the person has a magnesium deficiency. However, added magnesium can be very hazardous for persons who have difficulty eliminating magnesium, as happens with kidney insufficiency.

Common Causes of Cramps : Numerous medicines can cause cramps. Potent diuretic medications, such as furosemide (Lasix), or the vigorous removal of body fluids even with less potent diuretics can induce cramps by depleting body fluid and sodium. Simultaneously, diuretics often cause the loss of potassium, calcium, and magnesium, which can also cause cramps. Several vitamin deficiency states may directly or indirectly lead to muscle cramps. These include deficiencies of thiamine (B1), pantothenic acid (B5), and pyridoxine (B6). Poor circulation to the legs, which results in inadequate oxygen to the muscle tissue, can cause severe pain in the muscle. This commonly occurs in the calf muscles. While the pain feels virtually identical to that of a severely cramped muscle, the pain does not seem to be a result of the actual muscle cramping. This pain may be due to accumulation of lactic acid and other chemicals in the muscle tissues.

Treatment of skeletal muscle cramps : Most cramps can be stopped if the muscle can be stretched. For many cramps of the feet and legs, this stretching can often be accomplished by standing up and walking around. For a calf muscle cramp, the person can stand about 2 to 2½ feet from a wall (possibly farther for a tall person) and lean into the wall to place the forearms against the wall with the knees and back straight and the heels in contact with the floor. (Learn this maneuver at a time when you don't have the cramp!) Another technique involves pulling the toes up towards the head while still lying in bed with the leg as straight as possible. For cramps such as those that occur in writer's cramp, pressing the hand on a flat surface will stretch the cramping finger flexor muscles. Gently massaging the muscle will often help it to relax, as will applying warmth from a heating pad or hot soak. Interestingly, since the normal response of the muscle to cold is to shorten, ice packs may also relax a cramp. If the cramp is associated with fluid loss -- as is often the case with vigorous physical activity -- fluid and electrolyte (especially sodium and potassium) replacement is essential. Medicines are not generally needed to treat an ordinary cramp that is already present, since most cramps subside spontaneously before enough medicine would be absorbed to even have an effect. One enthusiastic non-scientific recommendation has been to firmly pinch the tissues above the lip, just under the nose, and hold the pinch until the cramp stops (said to be within 15 minutes.) Of course, why this might work, or even if it is causing anything that wouldn't have happened anyway, is uncertain, and no scientific study of this technique has been reported. In recent years, injections of therapeutic doses of botulism toxin have been used successfully for some dystonic muscle disorders that are localized to a limited group of muscles. A good response may last several months or more, and the injection may then be repeated. The treatment of cramps that are associated with specific medical conditions generally focuses on treating the underlying condition. Sometimes, additional medications specifically for cramps are prescribed with certain of these conditions. Of course, if cramps are severe, frequent, persistent, respond poorly to simple treatments, or are not associated with an obvious cause, the patient and the doctor need to consider the possibility that more intensive treatment is indicated or that the cramps are a manifestation of another disease. As alluded to above, the possibilities are extremely varied and include problems with circulation, nerves, metabolism, hormones, medications, and nutrition. It is not common that muscle cramps would result from a medical condition without some other obvious signs that the medical condition is present. In the long run, however, the most important aspect of dealing with common muscle cramp disorders is prevention.