What is it?
A muscle cramp, often referred to as a “charley horse,” is a temporary, involuntary contraction of a muscle. The calf, hamstring, and thigh (“quadriceps”) muscles are the most commonly affected. There are many potential contributors of muscle cramps, although the true cause is currently unknown. Possibilities include electrolyte abnormalities (sodium, potassium, magnesium, and calcium), inflammation, microtrauma (injury to the muscle), dehydration, heat illness, and fatigue.

Symptoms
The onset of a cramp typically begins with twitching of the muscle, followed by contraction and pain.

Sports Medicine Evaluation and Treatment
Stretching the affected muscle group remains the most reliable immediate treatment. Proper hydration with water or an electrolyte-containing fluid are important additions to treatment. If cramping is a frequent issue, a sports medicine physician may recommend bloodwork for further evaluation.

Injury Prevention
The cause of muscle cramps is not completely understood. However, based on an athlete’s history and when the cramping occurs, modification to certain factors may be helpful. This includes appropriate warm-up and stretching, hydration, acclimatization to heat and exercise intensity, and intermittent rest. Consultation with a physician for recurring cramps is recommended.

Return to Play
A functional assessment is important prior to return to play. There should be no further evidence of cramping prior to returning to activity. Playing through cramping will be unlikely to help and may in fact be harmful.

AMSSM Member Authors
Nick Monson, DO, and Fran O’Connor, MD

References
O’Connor, Francis G. MD, et al. ACSM’s
Sports Medicine: A Comprehensive
Review. China: Wolters Kulwer, 2013.