PT on the Net Research

Cause of Muscle Cramps


I have a client who experiences extreme cramping at seemingly random points of the day. He is in his 50s and works construction. He often cramps in his hand or his calves but not necessarily when we are working those muscles. He also tells me that this happens to him at home all the time. What should I tell him to do? I’ve suggested he stay hydrated and eat potassium.


Any involuntary and forcibly contracted muscle that does not relax can be defined as a cramp. Skeletal muscles (calves, quadriceps, hamstrings, etc.) are more prone to cramping. A muscle cramp can involve one muscle or several muscles in a concentrated area and can be due to electrolyte imbalances, dehydration or overexertion/repetitive movement tasks.

Cramps that happen in the presence of a higher heat/humidity index and during physical activity are most commonly associated with hydration and electrolyte imbalances. Educating clients about proper hydration strategies and proper eating habits (see below) are very important because some individuals do not realize the body’s need for increased nutrients during heat exposure and the increased loss of nutrients from sweat.

There are quite a few incidences of muscle cramping that are not associated with heat, humidity or exercise. These types of cramps can certainly be caused by fluid and electrolyte imbalances, but more often than not, overexertion and muscular fatigue can be the culprits. Individuals who have occupations that require repetitive movements continually overexcite the muscles, which causes muscle fatigue. Overexertion depletes the muscle of nutrients and oxygen, which can lead to a buildup of waste products and cause the muscle to spasm. Unfortunately, when a cramp begins, the spinal cord stimulates the muscle to keep contracting.

In addition to the above, age seems to play a factor as age related declines in muscle, termed sarcopenia, results in the muscles not being able to function as they once did. Therefore, similar actions of your clients in earlier years may not be as well handled by the skeletal muscle system to due biological aging. Completing repetitive tasks during the day either during work or physical activity could cause eventual fatigue in the muscles being activated, which can lead to cramping as discussed previously.

The following are practical suggestions you can implement with your client to try to prevent future muscle cramping:

  1. Stay hydrated. Muscles contain a large amount of water and water is required for proper functioning and the removal of waste products.
  2. Eat a wide variety of nutrient rich foods. Fruits, vegetables and whole grains contain many vitamins and minerals that the body needs for normal functioning and to remain in homeostasis. Sodium is the most important electrolyte for heat associated cramps. A blend of sodium, potassium, calcium and magnesium are more important for non-heat induced cramps that happen during normal activities of daily living.
  3. Follow a well planned exercise program. If a cramp is repetitive movement based, it is important to ensure that the muscles most often affected have good range of motion and are adapted for any physical stresses.

If muscle cramps continue to persist after eating and hydration strategies improve and a sound strength, conditioning and flexibility program are instituted, it may be advantageous to consult a physician since there may be other factors such as medications that may play a role in cramping episodes.