What is muscle cramp?
A cramp is an involuntary and forcibly contracted muscle, which does not relax. It is characterised by a sudden tight and intense pain, which remains for as long as the muscle is locked into spasm.
Muscles, which span two joints, are most prone to cramping and cramps can affect any muscle, or group of muscles, which are under our voluntary control (known as the skeletal muscles).
The most commonly affected muscle groups are:
- back of lower leg/calf muscles - known as the gastrocnemius.
- front of thigh muscles - known as quadriceps.
- inner thigh muscles - commonly referred to as hamstrings.
'The calf and thigh muscles are the principal muscle groups to be affected by cramp'.
It is also very common for people to experience cramps in the hands, arms, feet and abdomen and along the entire rib cage. A cramped muscle may feel very hard to the touch and may even look visibly distorted beneath the skin. The intense pain may last for only a few seconds or up to 15 minutes and there may be repeated bouts of cramp over a short period of time.
Why does it happen?
While the exact cause of muscle cramp is not known, some researchers believe that it is caused by inadequate stretching and muscle fatigue which, in turn, leads to a malfunction of the mechanism that controls muscle contractions. Other factors, which may lead to cramping, include working or exercising in intense heat, or becoming excessively dehydrated. Let's examine these causes more closely:
- muscles are basically bundles of fibres, which contract and expand to produce movement. Stretching lengthens muscle fibres so that they can contract and tighten more effectively during exercise. When someone with a poorly conditioned body embarks on a vigorous exercise programme without doing some form of stretching exercises beforehand, the inevitable result is muscle fatigue. This, in turn, leads to an alteration in spinal neural reflex activity, so that the electrical signals are mixed up.
- over-exertion causes a severe reduction in a muscle's oxygen supply, which leads to a build-up of waste product and spasm. When a cramp begins, the spinal cord stimulates the muscle to keep contracting, leading to severe pain.
- muscle cramps are much more likely to occur when exercising in very hot weather because sweating drains the body's fluids and also depletes essential supplies of salt and minerals such as magnesium, potassium and calcium. Loss of these essential nutrients can cause a muscle to go into spasm.
Who is at risk?
Almost everyone will experience a muscle cramp at some stage in his or her lives. It can happen when you are engaged in vigorous exercise or when you are comfortably tucked up asleep in your bed at night! Sometimes even the slightest movement may trigger an extremely painful cramp.
However, some people are more prone to cramps than others and may get them with even the slightest physical exertion. Muscle cramps are very common among endurance athletes such as marathon runners or triathletes, or among older people who continue to engage in strenuous physical activities. Athletes tend to develop cramps at the start of their training season when the body is not conditioned and is, therefore, more prone to muscle fatigue. They may also develop cramps at the end of an intense or prolonged exercise session, or even the night after.
Older people are generally more susceptible to muscle cramps than their more youthful counterparts. One of the reasons for this is due to normal muscle loss due to the ageing process (known as atrophy) which begins in the mid-40s and accelerates with inactivity. With ageing, muscles are no longer able to work as hard or as quickly as they used to. The body also loses some of its sense of thirst and its ability to sense and respond to changes in temperature.
How is it treated?
Cramps usually go away on their own without medical intervention. The first action to take is to stop doing whatever activity triggered the cramp - unless you were asleep in bed when your muscles went into spasm! Then, gently stretch and massage the cramping muscle, holding it in the stretched position until the cramp stops. If the muscles are tight or tense, apply HEAT. If they are sore or tender, apply COLD.
To prevent cramps, try to work to a better level of overall fitness. Also, remember to keep your body adequately hydrated by drinking plenty of fluids, especially in hot weather. Children, in particular, need to drink fluids often to replenish essential body fluids lost during play.
Here are some tips:
- drink water at regular intervals throughout the day, even before you get thirsty.
- always drink more than your thirst requires.
- drink fruit juice or a recommended sports beverage if you are sweating for more than an hour, or working in conditions of intense heat.
Should I see a doctor?
Under normal circumstances, there should be no need to see a doctor for muscle cramps. However, if cramps are severe, happen very frequently, respond poorly to simple treatments and are not related to obvious causes like exercise they could be symptomatic of a more serious underlying problem.
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