Walking from heel to toe optimizes energy consumption efficiency
“Sky News” – A recent study revealed that landing on the heel first while walking makes human movement more energy-efficient, an evolutionary advantage that may have helped human ancestors travel longer distances in search of food and hunting.
The study, published in the journal PNAS, showed that participants consumed 26 to 41 percent more metabolic energy when their midfoot touched the ground before the heel, compared to the natural walking pattern in which the heel strikes first.
Experiments showed that human steps during natural walking consistently began with the heel, whereas chimpanzees’ foot-strike patterns were more varied, often landing on the side or forefoot, with heel use being less common when walking bipedally compared to quadrupedal movement.
The range of foot-strike angles in chimpanzees was 2.4 to 8.6 times wider than the range recorded among human participants.
Researchers believe that the high energy efficiency provided by heel-to-toe walking may have given human ancestors a significant advantage when traveling long distances, aiding their foraging, hunting, and gathering behaviors.
However, this efficiency comes at the cost of increased impact forces experienced by the body upon ground contact.
Results showed that the rate of impact force loading in humans when landing on the heel was up to 162 percent higher than when landing on the midfoot, while the increase in chimpanzees during bipedal walking reached 138 percent.
Researchers noted that the evolution of larger heel bones and stronger lower-limb joints in humans may have allowed safe handling of these loads, while simultaneously benefiting from the reduced energy cost of heel-to-toe walking.
Researchers also measured oxygen consumption and carbon dioxide production in human participants to estimate energy expenditure across different walking patterns.
The findings suggest that consistent heel striking is a distinctive feature of human walking compared to chimpanzees, and may have been part of a suite of evolutionary adaptations that enabled human ancestors to move greater distances more efficiently.
