Work related musculoskeletal disorders (WRMSD) are diseases that question the making of the professional gesture. It said that the prevention of these multifactorial diseases needs interdisciplinary approaches. Our action is in line with the historico-cultural theory of activity (Vygotski, 1978). Research in clinic of activity organizes the subjects' action of appropriation of new means of action both on themselves and on the work situation. It always begins by an intervention within a specific professional environment. We answered the demand of the occupational medicine department of a big French city. WRMSD on the region of the shoulders and lumbers troubles have been diagnosed among municipal gravediggers. We led this intervention in psychology of work within a clinic of activity methodological frame open to interdisciplinary cooperation with ergonomics of activity and biomechanical analysis. Co- analysis of technical gestures within three gravedigger collectives has benefited from the methodological contributions of interdisciplinarity. The intervention has also allowed advances in the action of prevention initiated by managers and preventors together in a piloting committee. From a conceptual viewpoint the gesture is a physiological, psychological and social unit. In the psychological and social analysis of movement (Clot & Fernandez, 2005) this unit is comprehended in the complexity of its interfunctional dynamics (Luria, 1973). The development of the gesture is thought of in terms of qualitative reorganization of internal relations between automatism and gesture and between gesture and movement. This modelling is built on the model of the interfunctional relationships between operation and action and between action and activity (Léontiev, 1984) as well as on the model of directed activity (Clot, 1999). This theoretical route and our empirical findings show that the WRMSD are diseases linked to hypo-socialization of movement by lack of interferences between contexts of its realization. The dynamic of gestural controversies between professionals and the organization of inter-contextual interferences are analysed as indirect methods facilitating the socialization of the movement in order to prevent musculoskeletal disorders.