A Novel Method for Evaluating Loading Rate During Running Regardless of Impact Peak

Recently there has been a focus on the relationship between the characteristics of the vertical ground reaction force (vGRF) and running injury occurrence. [1,2] AVLR is defined as the slope of the vGRF-time curve following initial contact. There are several methods for computing AVLR in the literature, however, the 20-80% method can only be calculated in the presence of an impact peak, [3] typically only associated with a rearfoot strike pattern. Additionally, the 3-12% method is unreliable when the impact peak occurs earlier than 12% of stance phase. This presents a problem when computing, interpreting and comparing research findings amongst runners with different foot strike patterns. To our knowledge, no study has described a method that can evaluate AVLR regardless of time or occurrence of the impact peak. The purpose of this study was to introduce the 3-12% auto method for calculating AVLR and compare it to the 3-12% and 20-80% methods