You're relaxing on the sofa when suddenly your eyelid starts twitching. Or perhaps it's a muscle in your arm, your leg, or ...

Using powerful new visualization technologies, researchers have captured the first 3-D images of the structure of a key muscle receptor, providing new insights on how muscles develop across the animal ...

Time under contraction is not directly measured in a typical weight training program. Most people really don't even think about the number of seconds a given muscle is forced to work. Indirectly, ...

Medically reviewed by Jennifer Steinhoff, MD Key Takeaways Muscle strength grading helps evaluate muscle strength on a scale ...

A research group has uncovered important details about how platelet-activating factor (PAF)—a powerful molecule involved in inflammation and allergic reactions—triggers contractions in the smooth ...

Infectious agents can cause muscle twitching and spasms, too. The most commonly known is probably tetanus, which causes a phenomenon called lockjaw, where the neck and jaw muscles contract to the ...