Artists have always reproduced with realistic accuracy their images, most often made with the participation of models. Sandro Botticelli, in his work "Madonna and Child with Angels," painted the dorsal flexion reflex of the first toe from plant stimulation, four centuries before it was described in its clinical significance by French neurologist G. Babinsky.
"Normally, lightly crawling on the sole of the foot with a hard body (e.g., with the rounded end of a penholder or, as others practice, with a pin) from the heel to the toes, preferably near the inner edge, results in a response of toe flexion (plantar reflex). When there is, however, a perturbation in the functioning of the pyramidal bundle, the type of the plantar reflex may reverse, so that it is replaced by an extension movement of the big toe. This is the so-called toe phenomenon of Babinski, or rather the Babinski's sign; simply, a sure symptom of organic disease of the nervous system. It owes its name to the neurologist Joseph François Félix Babinski, born in Paris in 1857, author of other important works, notably on hysteria." Gioacchino Fumarola, Psychiatrist.
This scientific accuracy of painting had already been pointed out by doctors at Boston Children's Hospital. In children up to one year of age, dorsal flexion of the big toe caused by stressing the sole of the foot or the skin of the leg is a physiological phenomenon.
In the adult, conversely, it represents an important diagnostic sign characterizing lesions of the pyramidal nerve pathways. There are numerous images in which artists of different schools depict the child in the mother's arms with the first toe in a dorsal flexion position, evidently brought about by the contact of the child's foot or leg, which serves as a model, with the mother's hand or clothing.
The unusual dorsal bending position of the big toe must sometimes have created for the artists some not easy problems of perspective construction. In the works reproduced, some of them, seem to have intentionally solved the problem by resorting to the expedient of having that unruly big toe held firmly still, by the mother's hand.
From "Botticelli, an antelitteram neurologist. The scientific accuracy of painting" by Manfredo Fanfani.
