Abstract: Mahlon Locke was a Canadian physician who attracted international attention in the 1930s with an unusual therapy. Through a process of foot manipulation, popularly known as "toe-twisting," Locke seemed able to relieve many intractable cases of arthritis as well as a variety of related afflictions. Sufferers flocked to his clinic in Williamsburg, Ontario and, at the height of his fame, he was tending literally hundreds of people each day. Despite this spectacular public reaction, however, Locke is an obscure figure in Canadian history. People who lived through the Great Depression may remember the crowds lining the streets of Williamsburg or the media coverage of the clinic, but later generations are largely unacquainted with this unusual practitioner. One purpose of this paper, then, is simply to recapture and recount his story for the record. At the same time, Locke represents more than just a curious episode in Canadian history; he inspired strong and divergent opinions and the study of these reactions can help us to understand the social and medical climate of this period. In this discussion, I have focused on the attitudes of Locke's orthodox medical colleagues with particular attention paid to the disparate reactions of physicians in Canada and the United States. Thus, the other aim of this paper is to suggest that, despite shared definitions of health and healing, Canadan and American doctors responded differently to Locke as a result of fundamental differences in the tradition and character of each medical community.