Frenkel was born and later on practiced medicine in Heiden, Swizerland. This small town became, by his vigilant and innovative work, a place of pilgrimage for neurologists. He was the first to introduce the concept of exercise to restore dexterity and to improve ambulation and so pioneered the specialty of physical medicine and rehabilitation. Frenkel's method and philosophy became the foundation of treatment for many chronic neurological disabling diseases. His personality and work influenced many famous neurologists, worldwide.