The correlation between foot strike type determined by the two methods was 0.94 (p < 0.0001). Since the mean AOI only partially captures variation in strike types, a rank-order strike index was computed by assigning FFS, MFS, and RFS strikes scores of 1, 2, and 3, respectively, and then averaging. As noted above, several other kinematic variables were measured at foot strike and at midstance. Trunk angle was measured

as the angle between the greater trochanter and the center of the neck relative to horizontal. Step frequency for each trial was quantified by measuring the time between two foot strike events (calculated from the number of frames divided by frame rate). Overstride (here see more defined PI3K cancer as how far the ankle landed anterior to the knee) was measured as the angle of the lower leg (from the knee to the lateral malleolus) relative to earth horizontal at foot strike (an angle of 0° or less indicates no overstride, and higher angles indicate more overstride). An angular measurement of overstride was used instead of a linear measurement because there is less error in measuring the angle of the lower leg than in measuring the projected distance between the knee and ankle. Finally, to assess

general lower extremity kinematics, hip angle was measured as the segment from the knee to the greater trochanter relative to horizontal; knee angle was measured as the angle between the lines from the knee to the greater trochanter and the knee to the lateral malleolus; and ankle angle was measured

as the angle between the lines from the knee and to the lateral malleolus and from the lateral malleolus to the lateral metatarsal head. All angles were measured by visual inspection using ImageJ. Since the data were collected under field conditions it is not possible because to quantify accuracy, but reliability was assessed in two ways. First repeatability was quantified by taking the same set of measurements from one individual on five separate occasions. The average standard deviation was 0.32° with a range of 0.18°–0.49°. In addition, a test–retest sensitivity analysis conducted by taking all measurements twice from the same trial, yielding a correlation coefficient of 0.927. Kinematic measurements were averaged for each individual and compared among individuals and between minimally and conventionally shod groups primarily using t tests with footwear history (conventional or minimally shod) as the nominal, dependent variable. In addition, kinematic measurements were compared between individuals classified by strike type using ANOVA with modal strike type as the nominal, dependent variable.