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.

At the molecular level, muscle contraction is defined by myosin molecules pulling actin filaments. New electron cryomicroscopy images with unprecedented resolution taken by researchers at Osaka ...

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 ...