Episode 148: Leg Cramps
Future Dr. Weller explains the pathophysiology, management, and prevention of leg cramps. Hector Arreaza adds comments and anecdotes about leg cramps.
Written by Olivia Weller, MS4, American University of the Caribbean School of Medicine. Comments by Hector Arreaza, MD.
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Definition: Known also as “Charlie horses,” leg cramps are defined as recurrent, painful, involuntary muscle contractions. They can last anywhere from seconds to several minutes, with an average of nine minutes per episode. They are usually nocturnal and thus may be associated with secondary insomnia.
Location: A muscle cramp can happen in any muscle in the body, but they occur most commonly in the posterior calf muscles, but they can also involve the thighs or feet. They are more common in women than men and the risk increases with age.Although they are experienced by 7% of children and up to 60% of adults, the exact mechanism remains unknown and there is no definitive treatment at this time.
Pathophysiology
There is one leading hypothesis for nocturnal cramps that occur in the posterior calf muscles, and it is related to your sleeping position. When you are laying down in bed your toes are pointed which causes passive plantar flexion while the muscle fibers are shortened maximally. This causes uninhibited nerve stimulation with high-frequency involuntary discharge from lower motor neurons, which causes cramping.
Another possible etiology is nerve damage because neurologic conditions such as Parkinson’s disease are associated with a higher-than-normal incidence of cramps. Peripheral neuropathy, or damage to the connection between motor nerves and the brain can lead to hyperactive nerves when they are not being properly regulated. Thus, diabetes mellitus is a major risk factor for nocturnal cramps due to the high blood sugar levels damaging the small blood vessels which supply the muscles.
Decreased blood flow has also been attributed as a cause of leg cramps. People with diseases that affect their vasculature, such as varicose veins or peripheral arterial disease also have a higher incidence of leg cramps. Decreased blood flow to the muscles means less delivery of oxygen and nutrients to the muscles which makes them more susceptible to fatigue.
Muscle overuse is one of the dominant explanations for cramping. This can be related to doing too much high-intensity exercise without adequate stretching before and after. Pregnant women have added weight which puts extra strain on the muscles, along with sitting or standing for long periods of time, poor posture and flat feet. Notably, when we age, our tendons naturally shorten and they cannot work as hard, or as quickly which makes them more susceptible to overuse.
Additionally, there are mineral deficiencies such as magnesium and potassium or decreased levels of B and D vitamins. With this in mind, people with renal failure that are on hemodialysis have an increased risk of nocturnal leg cramps. And finally, we have medications, some of which are related to mineral deficiencies. The main contributors are statins, diuretics, conjugated estrogens, gabapentin or pregabalin, Zolpidem, clonazepam, albuterol, fluoxetine, sertraline, raloxifene, and teriparatide (analog for parathyroid hormone).
Management and prevention
There is no magic treatment to make them go away immediately, however, there are different remedies you can try to help facilitate. My Grandma told me about an old wives' tale, that if you put a bar of soap in your bed at your feet while you sleep, you won’t get cramps at night. Maybe it works by the placebo effect, maybe there's a mechanism going on there I don't understand who knows, I’ll have to do a study on it.
If you get them very often, you can keep a foam roller or a heating pad next to your bed in preparation for when they come. Stretching the muscle is known to be very effective, as well as applying heat or ice to the affected area. You can also try massaging the muscle with your hands or getting out of bed to stand or walk around. Elevating the leg while laying down in bed can also be beneficial.
In terms of prevention, you can try out different sleeping positions to see if one works better for you. If you usually sleep on your back, you can stick a pillow under your feet to help keep your toes pointed upward. Or, if you sleep on your stomach you can try to keep your feet hanging off the bed. Another tip is loosening the sheets or blankets around your feet.
Daily stretching, especially before and after exercise as well as before bed is useful. Make sure to exercise, stay hydrated, and limit your alcohol and caffeine consumption. You also want to wear supportive shoes or use orthotic inserts in your shoes, especially if you spend lots of time on your feet during the day.
Medications/supplements: Since various deficiencies can cause cramps, one way to prevent them is to take supplements such as magnesium, vitamin D, and B12 complex. And as a last resort, you can try medications. Calcium channel blockers such as diltiazem or verapamil have been used, and muscle relaxants including Orphenadrine (Norflex®) and Carisoprodol (Soma®).
Gabapentin is an anticonvulsant commonly used as a neuropathic pain medication; this used to be used to treat leg cramps but later it was found that they can actually increase the frequency of muscle cramps so they are no longer used. Quinine was also used for many years to treat leg cramps; however, it is no longer recommended because of drug interactions and serious hematologic effects such as immune thrombocytopenic purpura (ITP) and hemolytic uremic syndrome (HUS).
Summary: Leg cramps are common, the pathophysiology is unclear, but may be related to problems with blood flow, the nervous system, sleeping position, and muscle overuse. Treatment includes nonpharmacologic therapies such as changes in sleeping position, heat, and massaging; and medications/supplements that may be useful include Carisoprodol (Soma®), diltiazem, gabapentin (Neurontin), magnesium, orphenadrine (Norflex®), verapamil, and vitamin B12 complex.
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Conclusion: Now we conclude episode number 148, “Leg Cramps.” Future Dr. Weller explained that the etiology of leg cramps is multifactorial. Some theories about why leg cramps happen include poor circulation, muscle overuse, dysfunctions in the nervous and musculoskeletal systems, electrolyte imbalances, mineral deficiencies, and more. Some therapies were discussed, including changes in position while sleeping, massage, heat pads, and medications such as calcium channel blockers, muscle relaxants, and supplements of magnesium and Vitamin B12. Gabapentin is a medication that can cause leg cramps, but some sources recommend it as a treatment as well.
This week we thank Hector Arreaza and Olivia Weller. Audio editing by Adrianne Silva.
Even without trying, every night you go to bed a little wiser. Thanks for listening to Rio Bravo qWeek Podcast. We want to hear from you, send us an email at RioBravoqWeek@clinicasierravista.org, or visit our website riobravofmrp.org/qweek. See you next week!
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References:
- Leg Cramps. Cleveland Clinic. (2023, May 6). https://my.clevelandclinic.org/health/diseases/14170-leg-cramps
- Allen, R. E., & Kirby, K. A. (2012, August 15). Nocturnal leg cramps. American Family Physician. https://www.aafp.org/pubs/afp/issues/2012/0815/p350.html
- Mayo Foundation for Medical Education and Research. (2023, March 2). Night leg cramps. Mayo Clinic. https://www.mayoclinic.org/symptoms/night-leg-cramps/basics/definition/sym-20050813
- Royalty-free music used for this episode: Simon Pettersson - Good Vibes_Sky's The Limit_Main. Downloaded on July 29, 2023, from https://www.videvo.net/
