During this year World Cupone scene repeats itself game after game: Several players take the field with holes in the calves of their socks. Social media is full of theories about the supposed competitive advantage it can give them. But the practice is not new. It has appeared at the European Championships, Olympic Games, and other international competitions over the past decade. Still, science has yet to find evidence that it improves performance.
Professional soccer socks are, by design, form-fitting. In addition to holding the shin guards in place, they provide support for the ankle, arch, and calf; they help manage moisture and reduce foot movement within the cleat to improve stability. This design principle has been used in professional soccer for several decades. Although materials have evolved to become lighter and more durable, they are still primarily based on synthetic fibers such as polyester, nylon and spandex.
But quite a few players have complained that the socks are too tight and cause a feeling of stinging and numbness in the calf area. The discomfort is so great that, in the middle of the game, he cuts several holes in the calf area to “release the tension” and run better.
There is a biomechanical component to this sensation. During sprints or changes of direction, the larger muscles in the calf contract and increase in thickness to provide the force that propels the athlete forward. These shape changes occur thousands of times during the game. For some, the constant expansion of the muscles is enough to create a feeling of pressure when the sock makes constant compression on the calf.
Over time, the practice of cutting holes in socks has taken on an almost intuitive meaning among the players themselves: the splitting of the fabric allows the muscles to “breathe,” reducing pressure and reducing the likelihood of pain or cramps. However, sports medicine and rehabilitation experts say that there are no studies that show that cutting holes in socks provides any benefit. In fact, most research on compression garments concludes that, when properly designed and fitted, they can help reduce muscle inflammation after intense exertion.
Despite the lack of evidence regarding psychological benefits, exercise continues to be widespread among professional soccer players. Today, it is considered a common thing, according to each player personal experience instead of scientific evidence. Additionally, the rules of the game do not prohibit adjusting socks, as long as the equipment remains secure and the shin guards remain properly covered. (A soccer player, however, cannot play with a torn jersey.)
Given the lack of scientific evidence, several experts believe that part of the phenomenon can be explained by the player’s own perception of comfort. In high-level sports, the feeling of comfort can affect the confidence with which an athlete competes. If a soccer player believes a piece of clothing is restrictive, removing that perceived discomfort can make them feel more free to run, accelerate, or change direction—even if their performance remains unchanged.
Although there is no evidence that cutting socks provides a competitive advantage or reduces the risk of injury, that does not mean the discomfort is imaginary. The perception of pressure, restriction, or comfort depends on many factors, from the individual’s anatomy and sensitivity to the athlete’s past experience. In other words, two players can react differently when wearing the same equipment.
For now, it seems the sock cutting will continue. The available evidence points to a mechanism similar to that of other sporting rituals: Its effect is primarily psychological, not psychological.
This article appeared previously WIRED in Spanish and translated from Spanish.
