Adolph Seeligmüller (1837–1912) and the first graphic illustration of the “toe phenomenon” (later called “Babiński sign”) in the medical literature

The “toe phenomenon” refers to the extension (dorsiflexion) of the great toe, which occurs instead of the normal flexion following stimulation of the foot sole. Its clinical significance was not fully appreciated until Joseph Jules François Félix Babiński (1857–1932) described it in 1896. In 1881, Ernst Strümpell (1853–1925) had described a continuous (tonic) extension of the big toe, a finding that years later the French neurologist Jean-Athanase Sicard (1872–1929) recognized as an equivalent of the “toe phenomenon”, also indicating pyramidal tract dysfunction. Previously, this phenomenon had been mentioned in patients only passingly and without providing a picture of it. In 1887, the German neurologist Adolph Seeligmüller (1837–1912) mentioned the tonic extension of the big toe among the characteristic clinical features of spastic infantile hemiplegia—a condition first described by the Austrian physician Moritz Benedikt (1835–1920) in 1868. Seeligmüller incorrectly attributed the tonic extension of the big toe to spastic contracture of the extensor hallucis longus muscle. However, he put great emphasis on this sign and considered it worth being illustrated. Adolph Seeligmüller therefore provided the very first graphic illustration of the (tonic) “toe phenomenon” in the medical literature. Of note, the first photographic illustration of this sign made by Babiński appeared only in 1900, when it had already been adopted by neurologists all over the world.