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.

Numerous motor and structural proteins compose a highly ordered structure known as the sarcomere, the basic unit of muscle contraction in heart and skeletal muscles. Sarcomeric myosin heavy chain ...

Researchers have just made the unexpected discovery of a novel organization of muscle fibers in Parophidion vassali, a fish that lives in the Mediterranean Sea and, like many fish, uses specialized ...