A muscle cramp almost always strikes without warning. The involuntary contraction can appear suddenly, for example as an intense cramp in the calf during the night. Madhuri Kale, a physiotherapist at Brigham and Women's Hospital, who works with Harvard University, explains what causes cramps and how to relieve and prevent them.
What to do the moment a cramp strikes
According to Kale, the instinct to tense the muscle further is the wrong one. "When it appears suddenly, do not exercise and do not try to tighten the muscle further. Instead, gently stretch it as far as you can bear. This helps the muscle relax and stops the uncontrolled contraction," she says.
What causes muscle cramps
Intense exercise without proper warm-up can lead to muscle cramps. Cramps can also occur when a muscle is unable to relax properly, for example due to a lack of magnesium or potassium in the diet, or when it becomes irritated by a build-up of lactic acid, which can happen when the body does not rest sufficiently after intense exertion.
Dehydration worsens both of these conditions. Kale notes that many older adults avoid drinking enough water in the evening because they do not want to get up during the night to use the bathroom, which leaves them dehydrated.
Reduced blood flow to the muscles can also cause cramps. This can result from the narrowing of the arteries in the legs due to atherosclerosis. Sometimes, however, the cause is less expected. "Some people say they get cramps at night when their feet are left outside the blanket. The cold can cause blood vessels to constrict," Kale says.
Cramps may also stem from nerve dysfunction caused by neurological conditions such as Parkinson's disease, peripheral neuropathy, or spinal problems that press on nerves in the lower back. Even common foot conditions, such as flat feet, can contribute to their occurrence.
Kale also notes that certain medications, such as diuretics, can trigger cramps because they lead to both dehydration and electrolyte imbalances. Statins, by contrast, more commonly cause widespread muscle pain and only rarely cause muscle cramps.
How to relieve a cramp
Madhuri Kale recommends simple stretches that can offer immediate relief, depending on where the cramp occurs.
Calf cramp at night: "Sit up in bed, wrap the blanket around your foot and gently pull your toes towards you, keeping your knee straight."
Shin cramp: "Stand next to the bed, balance on your toes and lift your heels. This gently stretches the muscle that has cramped."
Lower back cramp: Kale recommends the yoga pose known as Child's Pose. "Kneel on all fours. Exhale and move your hips back until your glutes touch your heels. Without moving your glutes, lower your forehead towards the floor and stretch your arms out in front of you, palms on the ground. Hold the position for a few seconds and slowly return to the starting position while inhaling."
Hamstring cramp: "Sit on the floor with your legs stretched out in front of you. Slowly slide your hands along your legs until you feel a gentle stretch in the cramped muscle. Hold the position for about 30 seconds and slowly return to the starting position."
Once the stretch is complete, Kale recommends applying a heating pad or warm compress to the area to increase blood flow, followed by gently massaging the muscle.
How to prevent cramps
Kale recommends the following steps to reduce the likelihood of cramps:
- Stay well hydrated throughout the day
- Eat foods rich in magnesium, such as leafy green vegetables
- Get enough potassium from foods such as bananas and black beans
- Wear warm socks at night if leg cramps occur frequently
- Keep muscles strong and flexible through regular exercise
"Cramps are extremely painful, but they are not a sign of serious illness. Stretch the muscle and return to your activities once the cramp has passed," Kale says.
With information from health.harvard.edu
