From photography to cinematography: recording movement and gait in a neurological context.

The major challenge of photography has been freezing movement, to transform it into a fixed image or series of images. Very soon, photographers became interested in movement itself and tried to use photography as a tool to analyze movement. At the early stages, physicians interested in movement, perhaps surprisingly, made important technical contributions. Mécanisme de la physionomie humaine, by Duchenne, the first book with physiological experiments illustrated by photographs, is a landmark in this historical development. At the Salpêtrière, thanks to Charcot, photography officially entered clinical neurology. Medical journals with photographs were actively developed by Bourneville. Londe established a clinical photographic laboratory and published the first book on medical photography. The study of animal and human movement by Muybridge and Marey in the 1880s led to chronophotography and later cinematography. Clinicians such as Dercum and Richer took advantage of these new techniques to study pathological movement and gait in neurological diseases.