Comparison of instantaneous ankle and midfoot joint power during stance computed using two different foot models.

The foot models were: SINGLE—single segment foot (solid blue), and MULTI—multi-segment foot (dotted red). The "midfoot joint” is defined as the orientation of the FF segment relative to the RF segment and represents the collective function of all the joints between the talus and metarasals (midtarsal and tarsometatarsal joints). For both A and B: data computed from barefoot running at 3.1 m/s. Shaded regions show ± 1 S.D. Bottom plot shows results from a paired t-test, with the red dotted lines representing the t-statistic threshold for statistical significance. Gray shaded areas outside of the red dotted lines show regions with significant differences between SINGLE and MULTI (A) or the ankle and midfoot joints (B).