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.

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 ...

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’re relaxing on the sofa when suddenly your eyelid starts twitching. Or perhaps it’s a muscle in your arm, your leg, or your foot that begins to spasm – sometimes for a few seconds, sometimes for ...

Eccentric exercise focuses on movements, or phases of a movement, that lengthen the muscles. Some examples of eccentric exercise include lowering into a squat or lowering into a press-up. In contrast, ...

Much like their name implies, the quadricep muscles were once thought to be a set of four muscles, with the name “quad” translating to “four or fourth” in Latin. However, it has since been discovered ...