First described by German neurologist Oskar<unk>  (1871–1917) in 1915,<unk>  is a sustained involuntary contraction of a muscle after a prolonged voluntary contraction. The simplest demonstration, sometimes called "the floating arms experiment", is to have a subject press the arms against a door frame or wall for about thirty seconds, and then step away. The arm will involuntarily rise. Russian scientists Victor Gurfinkel, Mikhail Lebedev and Yuri Levick used<unk>  to activate tonogenic structures in humans and thereby demonstrate postural automatisms, such as neck reflexes.
Kohnstamm's phenomenon
Bell's phenomenon
Uhthoff's phenomenon
Lucio's phenomenon
Renbök phenomenon
Tullio phenomenon
Linburg–Comstock variation
Hutchinson's sign