Fig. 7. Stick figure of the leg during swing during walking (open circles) and running (filled circles) at three normalised speeds for one subject. The three leg positions shown correspond to toe-off, middle swing and touch-down. Circles denote markers on the calcaneus, the fifth metatarsophalangeal joint, the lateral malleolus, the estimated centre of the knee joint, the greater trochanter and the iliac crest. Walking and running figures at a given speed are aligned such that the hip horizontal coordinates of the stick figures at toe-off coincide. The trajectory of the iliac crest is superimposed on the stick figures. The thigh angular amplitude is larger during walking than during running, whereas the vertical excursion of the iliac crest, the distance travelled during swing and the magnitude of knee flexion during swing are larger during running than during walking. A speed of 100% corresponds to the gait transition speed.