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.

Add Yahoo as a preferred source to see more of our stories on Google. Many of us have felt a muscle in some part of our body suddenly and involuntarily tighten, causing a twitch or even severe cramp.

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 ...