in many diseases. Though excitation–contraction coupling has been known for over half a century, it is still an active area of biomedical research. The general scheme is that an action potential arrives to depolarize the cell membrane. By mechanisms specific to the muscle type, this depolarization results in an increase in cytosolic calcium that is called a calcium transient. This increase in calcium activates calcium-sensitive contractile proteins that then use ATP to cause cell shortening. The mechanism for muscle contraction evaded scientists for years and requires continued research and updating. The sliding filament theory was independently developed by Andrew F. Huxley and Rolf Niedergerke and by Hugh Huxley and Jean Hanson. Their findings were published as two consecutive papers published in the 22 May 1954 issue of Nature under the common theme "Structural Changes in Muscle During Contraction". See also Anatomical terms of motion calcium-induced calcium release Cardiac action potential Cramp Dystonia Exercise physiology Fasciculation Hill's muscle model Hypnic jerk In vitro muscle testing Lombard's paradox Myoclonus Rigor mortis Spasm Uterine contraction References Further reading Saladin, Kenneth S., Stephen J. Sullivan, and Christina A. Gan. (2015). Anatomy & Physiology: The Unity of Form and Function. 7th ed. New York: McGraw-Hill Education. Krans, J. L. (2010) The Sliding Filament Theory of Muscle Contraction. Nature Education 3(9):66 External links Sliding Filament Model of Muscle Contraction Animation: Myofilament Contraction Exercise physiology Muscular system Skeletal muscle Musculoskeletal system Neurology