Evaluation of shock absorption properties of rubber materials regarding footwear applications

A challenge that faces the footwear market is the improvement of casual shoe comfort, being shock absorption one of the most significant properties for comfort. However, the methodologies available for the quantification of the shock absorption properties in materials for footwear applications are limited. With this work, an evaluation methodology of the shock absorption properties of rubber materials is proposed and the relationship between different test methods is established. Eight different commercial compact heeled rubber materials at six different thicknesses were prepared and characterized according to their physical and impact absorption properties. From the experimental values, the following correlations were defined: energy compression/hardness and energy compression/maximum deceleration. Shock absorption prediction curves were also determined from the experimental maximum deceleration values. Results present an excellent tool for industrial applications since they allow correlation of shock absorption properties and heel thickness, and also to predict the contribution of rubber material composition to the final product shock absorption properties.