Activity analysis is one of the foundations of ergonomics. It is continuously evolving in a steady search for better ways of adaptating the methods available to present and future occupational situations. Indeed, as working conditions change rapidly, the methods for analysing activity must be reviewed and adjusted to better meet these changes of reality, in their various forms. For this reason, in parallel to actual work-related activity, emotions at work are increasingly a subject of analysis. At a time when psychosocial risks are of concern to many, taking this emotional dimension into account is even more relevant. This article describes a research and intervention project carried out in a company in the home healthcare sector. With a basis in psycho-ergonomics, the approach relies on a method of analysing activity and emotions through the use of collective self-confrontation. In this case study, we detail the method used and the results it produced, and we present a methodological reflection on the question of how analysis and intervention methods can be adapted to these aims. We show that the methods used to analyse activity and emotions based on collective self-confrontations have their full place in improving working situations, and more precisely, preventing psychosocial risks. We show how this method has sought to adapt to the changes that have occurred in the world of work, while at the same time respecting the actual foundations of the methods used to analyse activity. This methodological adaptation is discussed in the context of the prevention of psychosocial risks.