Fig. 4.

Profiles of body stability during limb cycles in painted turtles. (A) Heave measured in body lengths (BL). Eight randomly selected representative trials indicating variable, non-cyclic patterns during the course of a limb cycle. Positive and negative values indicate that the lateral center of rotation (COR) is above or below the path of travel, respectively. (B) Pitch. Eight randomly selected representative trials indicating variable, non-cyclic patterns during the course of a limb cycle. Positive and negative values indicate that the turtle is pitched upward or downward relative to the path of travel, respectively. (C) Sideslip measured in body lengths. Mean profile (all trials) during limb cycle showing cyclic behavior. Symbols represent means ± s.e.m. (N=96). Positive and negative values indicate that the ventral COR is displaced to the left or right of the path of travel, respectively. (D) Yaw. Mean profile (all trials) during limb cycle showing cyclic behavior. Symbols represent means ± s.e.m. (N=96). Positive and negative values indicate that the body is yawed to the left or right of the path of travel, respectively. In addition, because the maximum value for a given trial does not always occur at the same percentage of the limb cycle, it is also possible that calculated maximum values may be different from the maximum values seen in mean kinematic profiles.