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 ...

Proprioceptive neuromuscular facilitation (PNF) is a form of assisted stretching. It combines passive stretching with muscle contraction. First, your partner applies force to stretch your muscle ...

At one point or another, we’ve all experienced the unexpected, intense pain of a muscle cramp. Muscle cramps, also known as muscle spasms or charley horses, are the involuntary contraction of muscle ...

Myotonic dystrophy type 1 (DM1) is the most common form of adult-onset muscular dystrophy, affecting about 1 in 8,000 people. While it is well known for causing muscle weakness and stiffness, DM1 also ...

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.