Add Yahoo as a preferred source to see more of our stories on Google. A muscle spasm, also known as a cramp, twitch or charley horse, is the sudden and involuntary forced contraction of a muscle.

Medically reviewed by Smita Patel, DO Hypnic jerks are sudden muscle contractions that happen as you fall asleep. They are ...

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Clonus reflex is a set of rhythmic, involuntary muscle movements. It is a neurological condition that affects the nerve cells that control muscle movements. Damage to the nerves, as in clonus, causes ...

Though many people experience muscle twitching, it's often incorrectly identified as a muscle spasm. While both are involuntary contractions of a muscle, muscle spasms and muscle twitching aren't ...

In a serendipitous discovery, UC San Diego researchers using cryo-EM technology captured the first visualizations of the 3-D structure of the muscle acetylcholine receptor in fetal and adult muscles.

You may get muscle cramps from dehydration, mineral loss, or overuse during exercise. Warm up and stretch your muscles before ...

We've all been there before. Running along the basketball court or swimming across the pool, when, all of a sudden, we experience a sharp pain in our foot or leg. Muscle cramps are common, affect ...