Work is often studied according to macro-categories (institutions, interactions, processes, etc.). As a complement to such approaches, this article discusses the interest of also observing the details, the micro-processes of the activity, often neglected because considered minor. It shows that the micrological analysis of work contributes to the production of knowledge on the activity, by proposing an intelligibility, but also brings praxeological perspectives, by allowing the accompaniment and the follow-up of the processes of professionalization in many trades. As an example, a study on the activity of psychomotricians is an opportunity to highlight the way in which the identification of micro-gestures of adjustment during a session of care of a patient-child makes it possible to better identify what constitutes the professional action in its central dimensions, while supporting the actions of reengineering of the training in progress in this profession. This contribution thus takes up a question that is both classic and still current in SHS, which is that of the conditions according to which a micro-type analysis of human activities makes it possible to document or support professionalization dynamics on a larger scale.