From the Brink of Scientific Failure

Fifty years ago, on April 12, 1955, Dr Thomas Francis, an epidemiologist on faculty at the University of Michigan, announced to the world that he had just completed a study demonstrating that the Salk vaccine was “safe, effective, and potent” in preventing paralytic poliomyelitis. He released findings that showed convincing statistical evidence that the Salk virus preparation was 80% to 90% effective.1 In the decades before Francis' landmark announcement, physical therapist management of patients with polio brought our profession to the forefront of public attention. Polio was the catalyst for some of the skills that today we regard as fundamental to physical therapist practice: advanced muscle testing, gait training, and the teaching of functional activities. With subsequent extensive commercial production and widespread distribution of the Salk vaccine (and, eventually, the Sabin vaccine), Francis' feat ultimately led to the eradication of polio in the United States and, concomitantly, to a drastic change in the physical therapy profession. We began as a small cadre of physical therapists who tended primarily to wounded soldiers needing rehabilitation and to people who had polio. With the end of the polio epidemics, we applied foresight and courage both to bring our unique skills to many other types of patients who were in critical need of our interventions and to convince society of the value of our services. The process continues to this day. Few today appreciate how remarkable the Francis …