Reader's Digest 6月号の記事 'Your Amazing BODY' から引用します。
You get a charley horse. "Charley horse" is a nice nickname for a nasty muscle cramp, commonly in your calf. One study found that the nerves inside the muscle can fire up to 150 electrical charges per second during a cramp, which is what forces the muscle to squeeze so tightly. The potential causes include dehydration, over-exertion, and certain medications, such as diuretics.
文中に "charley horse" の意味の説明がありますが、この表現は４年前（8/17/2015）にも取り上げていました。
You get a charley horse. "Charley horse" is a nice nickname for a nasty muscle cramp, commonly in your calf. One study found that the nerves inside the muscle can fire up to 150 electrical charges per second during a cramp, which is what forces the muscle to squeeze so tightly. The potential causes include dehydration, over-exertion, and certain medications, such as diuretics.
文中に "charley horse" の意味の説明がありますが、この表現は４年前（8/17/2015）にも取り上げていました。
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