Muscle contraction is the tightening, shortening, or lengthening of muscles when you do some activity. It can happen when you hold or pick up something, or when you stretch or exercise with weights.

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.

MICKLETON, N.J. (WPVI) -- Nearly everyone gets a muscle cramp from time to time. When muscle contractions won't stop and can't be controlled, that's called dystonia. A South Jersey man is now sharing ...

The flow of water within a muscle fiber may dictate how quickly muscle can contract, according to a new study. The flow of water within a muscle fiber may dictate how quickly muscle can contract, ...

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 ...

You have 20 muscles in your forearm, the part of your arm between your elbow and your hand. They help you move your arms, hands, and fingers and perform many of the tasks of daily life. You can strain ...