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.

Muscle twitches fall into two main types. There’s myoclonus, where a whole muscle or group of muscles twitch or spasm. Then ...

When labor begins, the uterus must coordinate rhythmic, well-timed contractions to deliver the baby safely. While hormones such as progesterone and oxytocin are key contributors to that process, ...

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 ...

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 ...

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.