The previous chapter suggested that social movement theory offers a useful lens with which to study the field of arts, health and well-being. As well as highlighting research challenges and development processes, social movement theory examines boundary work as a way of reducing divisions between groups, empowering marginalised voices, transforming identities and generating new knowledge. The study of boundaries, which can be physical and symbolic, has developed in organisational and educational research and has been applied to healthcare research organisations. Boundaries serve to demarcate areas of knowledge, tasks and disciplines, and their enforcement can lead to problems such as silo working. Sometimes, boundary crossing is needed to highlight shared concerns, encourage collaboration and help to bring about change and innovation in policy and practice. The study of boundary work is highly relevant to arts, health and well-being and could help to understand how the various groupings involved can work effectively together.