Fig. 4.
Comparison of thigh angle, knee flexion, and tc for C4 versus other chimpanzees (n = 4). Thigh angles is measured as the angle between the thigh segment and the horizontal (e.g., thigh angle is 90° when the thigh is perpendicular to the ground). Knee angle is measured as the angle between the thigh and leg where full knee extension is 180°. tc is the time elapsed from touchdown to toe-off. Asterisks indicate significant differences between quadrupedal (blue) and bipedal (red) and strides (P < 0.05, Student's paired t test).