Chromatin remodelers are molecular motors which actively displace nucleosomes on chromatin. Recent results on the structural properties of these motors indicate that the displacement of nucleosomal DNA corresponds to an inchworm motion induced by the generation and propagation of twist defects. Here we show that this basic action mechanism can be described by a coarse-grained active Brownian dimer (ABD) model, thereby quantitatively rationalizing the notion of inchworm motion. The model allows for extensions to more microscopic as well towards more macroscopic descriptions of chromatin hydrodynamics.