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.

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, ...

The connections between the nervous system and muscles develop differently across the kingdom of life. It takes newborn humans roughly a year to develop the proper muscular systems that support the ...

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.

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