Fig. 5. Three time series of velocities of pelvis and left limb points in the three axes, for the same run as that presented in Fig. 3 (20.8 g, 1.4 m s^–1). The left foot footfall pattern is presented above A (see Fig. 3 for phase breakdown). Symbol definitions are as in Fig. 3. (A) Point velocities in the X (fore–aft) direction. All positive values indicate movement in the direction of motion, and all negative values indicate movement opposite the direction of motion. (B) Point velocities in the Y (vertical) direction. All positive values indicate movement upwards, and all negative values indicate movement downwards. (C) Point velocities in the Z (medio-lateral) direction. Positive values indicate medial movements, and negative values indicate lateral movements. Open symbols indicate when the foot is out of water, whereas closed symbols indicate that the foot is submerged.