Introducing tight bands in socks around the ball of the foot seems to make walking and running easier. The effects of these socks, which stiffen the feet, are equivalent to the reduced energy expenditure that the average person would experience if they lost 2 kilograms, according to the researchers behind them.
at the University of Texas at Austin says he hopes to see elite runners in the Los Angeles 2028 Olympics using these socks, which he developed with , also at the University of Texas at Austin. 鈥淥ur back-of-the-envelope estimates suggest that wrapping the foot in the new socks could improve marathon performance by 1 to 2 minutes,鈥� says Beck.
Since diverging from chimpanzees around 6 million years ago, human feet have become much stiffer than those of other apes, which assisted our bipedalism. Beck and Tang first wondered if they could take this stiffness further by tweaking footwear. However, previous attempts to reduce walking and running effort using shoes with stiffer midsoles or inserts have failed, so then the pair turned to socks.
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They are made of a common synthetic yarn blend, typical of athletic socks. Beck and Tang tightly knitted three 1-millimetre wide bands at a 30-millimetre-wide region around the ball of the foot. This results in 24 times more pressure being applied to feet compared with regular, control socks.
To test them, they recruited 12 adults of both sexes who had no known health conditions. The researchers analysed how they walked while wearing the foot-stiffening socks, control socks and no socks.
Participants then walked on a treadmill while wearing shoes with the stiffened socks and control ones for 5 minutes. Beck and Tang measured their VO2 max, the maximum amount of oxygen the body can absorb during high-intensity exercise. This allowed them to determine how much energy they burned in each of the walking experiments, known as metabolic expenditure.
The foot-stiffening socks reduced this expenditure in 10 of 12 of the participants by 2 per cent more than the control socks. That is equivalent to the average person losing 2 kilograms, according to the researchers.
This reduced expenditure probably doesn鈥檛 mean the socks lead to wearers getting fewer health benefits, such as weight loss, from walking or running compared with those wearing regular socks, says Beck. 鈥淩educing the whole-body metabolic rate means we have better walking endurance, we sweat less during hot days and we can walk faster for the same effort [that we would use] using commercially available socks.鈥�
The socks work by enabling the ankle and its muscles to push off at a slower velocity, he says. This requires less activation and less metabolic energy, leading to more economical muscle contractions. Unlike a stiffened shoe, the socks allow the toes to flex and the arch to recoil more freely, he says.
at the University of Oxford says the idea that a stiff foot makes walking less metabolically costly has been around for a long time, but nobody had managed to show it in people while they were walking until now. 鈥淭he team鈥檚 clever insight was that those earlier attempts [with shoes] also stopped the foot moving when it needs to, right at the end of the step.鈥�
The applications of the socks are yet to be tested. But Beck says that, in theory, anyone whose feet have lost some of their shape, say through old age, could benefit. The researchers already have a sponsored research agreement with the shoe company New Balance to commercialise the socks, says Beck.
However, P眉schel warns that other explanations for the results cannot be ruled out, such as the volunteers changing how they walked when they knew they had the socks on. 鈥淚t鈥檚 a promising first demonstration, rather than evidence that these socks will change anyone鈥檚 daily life,鈥� he says.
Royal Society Proceedings B
