If you notice the sole of every shoe now, most of them will have a slightly upturned nose. Design is called “spring toe“- or this toe spring acts as a booster for your every step. It will help shoes, especially sneakers, to be more comfortable and more comfortable.
But according to Daniel E. Lieberman, an evolutionary biologist at Harvard University: The upturned shoes possess the mechanism “spring toe“can also make your feet weak.
In the long run, they can lead to a number of problems such as hepatomegaly. That is what footwear companies in the same field of biomechanical research have ignored for a long time.
In their new research published in Scientific Reports, Lieberman and colleagues focused on the influence of toe spring design on walking and the biomechanical processes that occur in the feet. human.
“Most of us today wear shoes with a lot of features to increase comfort and protect the soles of the feet. But while many other features have been carefully researched, [tính an toàn và hiệu quả của] Toe springs are almost completely unproven“, the team wrote.
To answer unanswered questions, Lieberman recruited 13 volunteers to participate in his special experiments.
First, the volunteers were allowed to walk on a treadmill with bare feet. Then, they took turns repeating walking with 4 specially designed sandals with “spring toe“in the nose. Each pair of sandals has a different twist, from 10 degrees, 20 degrees, 30 degrees and 40 degrees.
The entire volunteer walk was recorded with load cells installed on the treadmill and infrared cameras. These measurements would allow Lieberman and his colleagues to calculate the energy, force, and muscle strength each volunteer puts on each step.
“Toe spring “is often designed to help the toe” roll “forward instead of bending.This will create a softer force, helping you to be more effortless during the push phase of the walk, When your heels have lifted off the ground“, the researchers wrote.
The mechanical benefits of this rolling motion have been demonstrated on shoes or sandals with curved soles, slotted bottoms. However, the negative influence of the mechanism “spring toe“No one has found out yet.
Analysis results from Lieberman’s experiment now show that the upturned sole reduces the amount of repulsion required by the ankle joints or MTP joint (where the toes connect to the rest of the foot bone). create.
Slope of “spring toe“The larger it decreases the strength of the MTP joint. This strength is determined by the muscle bundle”plantar intrinsic “ located on the soles of the feet.
The mechanics of MTP and the soles of the feet are what helped our ancestors start upright and effectively jog on two feet. As a result, Lieberman doubts wearing upturned shoes could be an evolutionary counter-evolution, and that it poses certain risks.
“Considering evolutionary history, humans have only worn shoes for a short time. There is little evidence that the shoe was an invention 10,000 years earlier than. And the shoes with lots of support features like the arch cushion, the base and the toe spring are even more new inventions.“, the team wrote.
“Through reducing the torque at the MTP joint, the upturned toe of the shoe can weaken the soles of the feet involved in the movement of this joint. Differences in individual terms are very small. But putting them in the context of a typical citizen in industrialized countries today walking 4,000 to 6,000 steps a day, they can have significant consequences.
“Wearing shoes with a custom toe spring mechanism can inhibit or reduce the ability of the soles of the foot to build energy.“Weakening of the soles of the feet has been shown to be linked to inflammation in this area, which causes pain, even loss of mobility, for more than 2 million Americans each year,” Lieberman added.
“Once the foot muscles have to work less, their stamina gets worse when you have to prop your feet thousands of times per day.“, Said Lieberman.”Plantar fasciitis is currently one of the biggest problems facing people today. It could be a result of weakening the leg muscles “.
However, the research team said they need more testing and statistics to confirm their hypothesis about the link between the mechanism. “spring toe“of upturned shoes and the problem it can cause.”
“This study isolates only one element of our shoes“, they said.”We’ll need more research to investigate how toe springs interact with other shoe elements like stiff soles or insoles. This can give us a more complete picture of how shoes affect our biomechanics.
In short, besides the comfort that upturned shoes offer, we also seem to have to pay for it. It’s like riding an elevator and sitting all day in chairs, the comfort of human invention seems to come with some potential side effect.