Fig. 6. Schematic right lateral views showing the effects of speed on the kinematics of the hindlimb. The uppermost cylinder in each figure represents the proximal portion of the tail, and the remaining objects are as in Fig. 2, and from proximal to distal represent the pelvis, the femur, the lower leg and the tarsals and metatarsals, respectively. To facilitate comparison of limb positions, the pelvis is shown at the same height within each row of figures, but in the real lizards the height of the pelvis relative to the tread surface did vary significantly within the stance phase. From left to right within each row that represents a different speed of locomotion, the average limb positions are shown at the beginning of stance and at the times of maximal (L_max) and minimal (L_min) length of the caudofemoralis muscle. Each figure illustrates the mean values (using all strides pooled across four individuals) of the dorsal and lateral angles of the proximal tail and the angles of pelvic rotation, femur retraction, femur rotation, femur depression, knee flexion and ankle flexion. The average times of maximum and minimum muscle length occurred within the stance phase when the foot touches the ground; however, this is not apparent in some figures because the height of the pelvis has been standardized and the toes are not shown.