Fig. 4. 2D scatterplot of loading pattern for all loading cycles from outdoor (grey) and treadmill (black) locomotion, showing fractional tensile strain ratio (FTSR) plotted against tensile strain orientation (TSO) for the cranial and caudal midshaft surfaces of both bones. Variability in pattern was greater during outdoor, non-steady behaviors than during steady treadmill locomotion (for descriptive statistics, see Table 2). Mean values for FTSR and TSO were nearly identical between outdoor and treadmill conditions. On average, the radius had a significantly higher percentage of footfalls that landed within the expected loading zones.