Figure 6.

(a) Risk factors for stress fracture can be categorized by their relationship to the load placed on bone (i.e. frequency, intensity, and duration of loading, load carriage, gate mechanics, etc.) (b) or by their effect on baseline bone stiffness (genetics, physical training and nutrition history, etc.). (c) A new category of risk factors is presented, characterized by their effect on adaptive bone formation (NSAID use, sleep deprivation, caloric restriction, and psychological stress). (A color version of this figure is available in the online journal.)