Mechanical exercise was legitimized in the American medical profession during World War One after it found direct application as a rehabilitative therapy. Therapeutic mechanical exercise was not a new phenomenon, having its initial manifestations in North America as early as the 1820s, but it tended to be a cure for the wealthy and had little practical application on a wider scale. Twentieth century industrialized warfare effectively democratized the battlefield and patient care through the sheer numbers of combat casualties – and opened the door to therapeutic exercise as accepted medical practice.

Contemporary medical exercise practice will be examined and contrasted by comparing the state of the art John Harvey Kellogg’s “Battle Creek” system of therapeutic exercise, the work of Robert Tait McKenzie, a Canadian doctor who became a driving force for the application of mechanical exercise to the rehabilitation of soldiers in North America, and records of the U.S. Army’s Surgeon General, which chronicle how American wartime medical practice evolved to place a major emphasis on soldier rehabilitation.

Although mechanical exercise as preventive medicine was still marginalized by the American medical profession, the American medical profession’s experience in World War One legitimized mechanical exercise as rehabilitative medical treatment, and emphasis that seems to have spread beyond treating military casualties. The impetus for this acceptance was undoubtedly the large numbers of returning citizen-soldiers requiring continued treatment. This necessity also spurred the U.S. government to provide rehabilitative medical services to veterans on an unprecedented scale, and anticipated the eventual creation of the Veterans Administration. World War One, as the first war in which battlefield casualties exceeded non-battle casualties, demonstrated that therapeutic exercise critical to successfully making soldiers fit once again for duty or civilian pursuits. In modern, industrialized war – or society, began to be as essential in helping repair the human bodies that other machines had helped injure.