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.

Tweaked by a muscle twitch? From an uncontrollable fluttering eyelid to a pulsing calf muscle, these small, rapid involuntary muscle contractions may happen at any time — and can be annoying. A common ...

Sometimes, people experience random muscle twitches that interrupt their normal daily activities. This is usually not harmful, but can produce discomfort. These random muscle twitches, known as ...