THE NATURE OF THE PLANTAR REFLEX IN EARLY LIFE AND THE CAUSES OF ITS VARIATIONS

INTRODUCTORY AND HISTORICAL  In 1898 Babinski¹ called attention to the plantar reflex as a diagnostic sign in lesions of the pyramidal tracts of the spinal cord. The reflex which he called le phenoméne des orteils consists, as is now so well known, of the plantar flexion of the big toe consequent on the tickling of the inner border of the sole of the foot. This is the normal response. When the pyramidal tracts are diseased in any part of their course, the same stimulus applied to the sole of the foot results in a dorsiflexion instead of a plantar flexion of the toe. Since then this peculiarity of the toe reflex in organic lesions of the pyramidal tract has become known as Babinski's sign or the Babinski phenomenon, and has been a subject of investigation by many observers all over the world, including Buzzard,² Collier,³ Cohn,⁴