“…As McKeon et al (2014) state, "Human runners are unique in needing to control balance during single leg support and for this reason (unlike quadrupeds) require a foot that is reasonably mobile, able to accommodate uneven substrates, and actively controlled." As illustrated in The Overpronated Foot e A New Paradigm (Wallden, 2010(Wallden, , 2014Figs. 5 and 6), not only does hominid bipedal gait require greater external rotator mass at the hip, but it also needs a mechanism at the foot end to provide adequate traction to counter this force e especially in the acceleration phase, or in turning (see accompanying practical paper).…”