A series of centrifuge tests was conducted to explore the deformation mechanisms mobilised in looseand dense sand for a complete set of active rigid retaining wall movement modes: rotation about thebase and top and translation. The sand deformation was measured by particle image velocimetry anddata relating to displacements and strains are reported. A simplified deformation mechanism isproposed for sand behind a rigid wall rotating about the top and this is validated with the centrifuge testresults. The paper reveals that the sand deformation caused by wall translation can be well characterisedby the superposition of mechanisms with equal but opposite wall rotation about the top and base.Integration of these displacement mechanisms together with a constitutive law into an equilibriumsolution for wall bending would allow designers to predict deformations during construction as well asultimate collapse