Fig. 2. (A) The mean joint angles at mid-stance versus body mass while running with a 0.40 duty factor (DF), for the hip (open circles), knee (closed diamonds), ankle (closed circles) and TMP joints (open squares). The equations for the least-squares regression lines (±95%CI for the slope) are as follows: hip, y=87.3+0.13x (±0.24, R²=0.07); knee, y=88.9+0.04x (±0.30, R²=0.01); ankle, y=127.2+0.06x (±0.17, R²=0.03), and TMP, y=112.0–0.03x (±0.12, R²=0.01). (B) Peak resultant ground reaction forces (F_R) normalized by body weight when running with a 0.40DF; y=2.24–0.004x (±0.006, R²=0.08). (C) A scaled stick figure representation of the typical emu hindlimb posture at the time of peak bone strains when running with a 0.40DF. The joint angles (mean ± s.d.) are as follows: hip, 86±9°; knee, 97±12°; ankle, 129±7°; TMP, 120±7°. F_R is oriented 1.7° from the vertical axis in the fore–aft plane, passing near the knee. Even though the TMP joint is inclined slightly relative to the toe (9°), the foot was flat on the ground at the time of peak bone strains.