Polymer materials may exhibit significant viscoelastic behaviour under various type of deformations. A model that can describe various viscous behaviours in simple tension was proposed in a previous work of the laboratory of biomechanical orthopedics. This model is interesting as it introduces descriptive material parameters that help in contrasting different viscous behaviours. The objective of this study is to assess if the model is also valid in simple shear. A device to perform simple shear was designed and tests performed on polyoxymethylene (POM), polyethylene terephthalate (PETP) and polycarbonate (PC).