Wear characteristics, i.e., the changes due to wear, which are evident both on the shoe and in the shoe impression, are an important part of the examination. The aspects of wear that are significant include the position of wear on the shoe and the degree of that wear. The position of wear on a shoe sole results from many factors, including the size, shape, and biomechanical function of the feet of the individual wearing the shoe as well as the extent and use for which the shoe is worn. The degree of wear of a shoe at any particular position on the sole is also significant as it is constantly changing as the shoe continues to be worn.