Socks with tightly knitted bands around the ball of the foot could make walking and running less energy-intensive, according to a small study led by researchers at the University of Texas at Austin. In tests, the foot-stiffening socks reduced the metabolic cost of walking by about 2 per cent compared with regular socks for most participants, an effect the researchers equate to the average person losing 2 kilograms.
The socks were developed by Owen Beck and Hui Tang, both at the University of Texas at Austin. They are made from a common synthetic yarn blend typical of athletic socks, with three 1-millimetre-wide bands knitted across a 30-millimetre-wide region around the ball of the foot. The bands apply about 24 times more pressure to the foot than in control socks. Beck said he hopes elite runners will wear the socks at the Los Angeles 2028 Olympics, and his team's back-of-the-envelope estimates suggest they could improve marathon times by 1 to 2 minutes.
The idea grew out of the observation that human feet have become much stiffer than those of other apes since humans diverged from chimpanzees around 6 million years ago, a change that helped support bipedal walking. Beck and Tang wondered whether footwear could push that stiffness further. Earlier attempts to reduce the effort of walking and running with shoes that had stiffer midsoles or inserts had not succeeded, so the researchers turned to socks instead.
To test the design, the team recruited 12 adults of both sexes with no known health conditions. Participants walked for five minutes on a treadmill while wearing shoes with the foot-stiffening socks, shoes with control socks, and no socks. The researchers measured each participant's VO2 max, the maximum amount of oxygen the body can absorb during high-intensity exercise, which allowed them to calculate how much energy was burned in each condition, known as metabolic expenditure. The foot-stiffening socks lowered this expenditure in 10 of the 12 participants by 2 per cent more than the control socks.
Beck said the lower energy use probably does not mean wearers gain fewer health benefits from walking or running than people in regular socks. « Reducing the whole-body metabolic rate means we have better walking endurance, we sweat less on hot days, and we can walk faster for the same effort, » he said. He explained that the socks allow the ankle and its muscles to push off at a slower velocity, which requires less muscle activation and less metabolic energy. Unlike a stiffened shoe, the socks let the toes flex and the arch recoil more freely.
Thomas Püschel at the University of Oxford said the idea that a stiffer foot makes walking less metabolically costly has been around for a long time, but no one had shown it in people while they were walking until now. He noted that earlier shoe-based attempts also stopped the foot from moving when it needed to, at the end of the step, and said the team's approach avoided that problem. Beck said that in theory anyone whose feet have lost some of their shape, for example through ageing, could benefit, but the applications have not yet been tested.
The researchers have a sponsored research agreement with the shoe company New Balance to commercialise the socks, Beck said. Püschel cautioned that other explanations for the results cannot be ruled out, such as volunteers changing how they walked once they knew they were wearing the socks. « It's a promising first demonstration, rather than evidence that these socks will change anyone's daily life, » he said. The findings were published in the journal Royal Society Proceedings B.
Source: newscientist.com
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