Earlier, we discussed whether barefooters should naturally walk with a heel-toe or a toe-heel stride. It is clear that the higher heel on a shoe automatically distorts whatever the natural barefoot gait would use.
We know from Dr. Lieberman’s research on running barefoot that the natural barefoot stride has the running landing either mid-foot or slightly on the fore-foot. This greatly reduces stresses on the body by more-or-less eliminating the transient created by the heel striking the ground.
Well, there is new research out on barefoot walking, and some of the differences between heel-toe and toe-heel walking. The study is The influence of foot posture on the cost of transport in humans, J Exp Biol 2010 213: 790-797, by C. B. Cunningham, N. Schilling, C. Anders, and D. R. Carrier. The paper appears in The Journal of Experimental Biology. The study does not look at the forces on the foot or the body, but instead looks at the efficiency of the two modes of walking.
According to the study, it takes about 53% more energy to walk on the balls of your feet than to heel-strike when walking. There’s a nice story on the the study at Physorg.com and another one in the Salt Lake Tribune. Note that this does not affect Dr. Lieberman’s results on barefoot running. When running, this newer study did not see any energy difference between rear-strike and fore-strike running.
So, how does this affect our earlier discussion, in which we noted that some barefooters walk heel-toe and others walk more toe-heel? For one thing, it does justify the discussion about the size of the calcaneal bone and the amount of padding beneath it. It really is more “natural” to walk with the heel hitting the ground first. However, even those who walk with hitting their heels first don’t really strike with their ball or their toes. At noted there, they tend to land mid-foot, with the heel coming down and a final, quick rotation of the foot on landing. I’m not sure just what that effect might have on energy efficiency, but I bet it is nowhere near as much as the effect for ball landing.