Leg cramps are a common medical malady that can affect all ages. Many individuals experience leg or muscle cramps in relation to specific activities, for example during exercise. However, in others, pinpointing the cause of a cramp may not be so straightforward.
Muscles are designed for locomotion. That is, they allow movement of the body by moving the bones to which they are attached. Each muscle is attached via a tendon to a bone at one end, its “origin;” and to another bone at its opposite end, its “insertion.” Between the two bones is a joint. When the muscle contracts, it shortens and moves the bone at the hinged joint.
The gastrocnemius is the large lower leg muscle in the calf. It is a common muscle in which to develop muscle cramps. It originates on the femur bone, crosses the knee joint, and then inserts on the heel bone via the Achilles tendon. Contracting this large muscle moves the foot downward, like stepping on the gas pedal.
Skeletal muscles like the gastrocnemius muscle are voluntary muscles. This means we can willingly control them – make them contract and cause movement. Involuntary muscles, like the heart muscle and the muscles of the digestive tract operate automatically. We do not have to will the heart to beat several times per minute or the stomach to digest our food.
However, we can have involuntary muscle contractions or movement in muscles we normally voluntarily control. Most everyone has at one time experienced a temporary twitch in an eyelid or hand muscle; or a more severe involuntary muscle contraction commonly referred to as a “charley horse” in the thigh or calf. These occurrences are most commonly caused by fatigue, dehydration, or exercise or a combination of these factors.
Less commonly, muscle cramps can be the result of poor circulation, anemia, and nerve disorders. Some medications can predispose individuals to getting muscle cramps. Fluid pills (diuretics) can alter the electrolytes in the blood, particularly potassium. Cholesterol medications can also cause muscle aches by affecting enzymes in the muscle tissue in some people.
Muscle spasms can be sudden in onset and very painful. Athletes can experience cramping during intense activity. Excessive perspiration leads to the loss of electrolytes through the skin. Since the muscles and nerves rely on chemicals such as potassium, calcium, sodium, and chloride to function properly, muscle cramping can occur. Many people experience leg cramps or cramps in the feet and toes at night, especially as they get older. In general, the cause of these nighttime leg cramps is unknown.
When muscle cramps occur, there are several things you can do to help ease them, such as massaging, stretching, or icing the muscle, warming the muscle, or taking a warm bath with Epsom salt. To help reduce the risk of cramps in the future, stay well-hydrated; exercise regularly and stretch properly before exercise; and eat healthy foods high in essential vitamins and minerals.
In most cases, self-care measures are sufficient for dealing with muscle cramps. Most will typically go away within minutes. However, if you experience them frequently or for no apparent reason, you should speak to your doctor. They could signal a medical problem that requires treatment.
The content in this column is for informational purposes only. Consult your physician for appropriate individual treatment. Dr. Reynolds practices Family Medicine in Chesterfield.
