Fig. 4

A Scatter plot of the included articles. Articles for each footwear design feature are separated by the number of articles considering covariates (y-axis) and running-related biomechanical risk factors (x-axis). If applicable, covariates for each footwear design feature are reported. According to a recent Delphi study, scatters are scaled to their importance [25]. Larger diameters represent a higher level of importance, and smaller diameters a lower level of importance. White scatters were not reported in the Delphi study and are not scaled