Kohnstamm's phenomenon

The Kohnstamm effect ( or the Kohnstamm phenomenon) describes an involuntary contraction of the muscles after prior intensive muscle tension. The term goes back to the German neurologist and psychiatrist Oskar Kohnstamm (1871-1917), who introduced him in 1915. In a concentrated thought process or a meditation muscles can perform smallest jerk and twitching or jerking movements, which are coordinated with unconscious mental content and ideas. The smallest muscular movements are well determined by measurement and can be felt by individuals.

The Kohnstamm effect may play a role in the emergence of movements of dowsing rods at dowsers together with the Carpenter effect.