Nurse Irene Shea studies the "Kenny method" of treatment of infantile paralysis, 1942-1943

In the 1940s nurses in the United States set out to learn the Kenny method of treating polio patients, which relied on hot packs and muscle strengthening exercises instead of the standard system of prolonged immobilization. Named for Sister Elizabeth Kenny, an Australian nurse who based herself in Minnesota during the 1940s and early 1950s, and viewed with suspicion by many physicians, nurses, and physical therapists, the treatment nonetheless proved effective. It changed the practice of polio nursing and the experiences of patients in the years before vaccine prevention largely eliminated paralytic polio.