This paper explores the role of material design as a form of institutional power within contemporary school settings. Drawing on concepts of "coercive design" and "hostile architecture" from design studies, the paper examines three "innovative" designs for classroom chairs -- relatively mundane but integral elements of the regulation and disciplining of school space. It is argued that the design intentions of these material objects reveal a number of constrained, conservative intentions to maintain the traditional ordered notion of the classroom as a place where students stay in their seats and engage in work. Tellingly, however, this corporeal manipulation and moderation is now couched in claims around desirable physiological and cognitive conditions for learning -- with students' bodies seen as objects to arrange and constrain in ways deemed conducive for learning. The paper problematises this de-socialised view of classrooms, alongside the underpinning sense of design solutionism and (mis)appropriation of "learning science" by product designers to justify their products' capacities to somehow cause learning to take place.