This year In the World Cup, one scene repeats itself game after game: Several players take the field with holes in their calf socks. Social media is abuzz with ideas about the competitive advantage this could give them. But the trend is not new. It has appeared in the European Championships, Olympic Games, and other international competitions over the past decade. However, science has yet to find evidence that it improves performance.
Soccer socks, by design, are symmetrical. In addition to holding shin guards in place, they support the ankle, ball of the foot, and calf; they help manage moisture and reduce foot movement within the cleat to improve stability. This design principle has been used in professional football for decades. Although construction materials have changed to become lighter and more durable, they are still primarily based on synthetic fibers such as polyester, nylon, and spandex.
But a few players have complained that the socks are too tight and cause tingling and numbness in the calf area. The discomfort is so great that, during the game, they cut several holes in the calf area to “relieve the tension” and run better.
There is a biomechanical component to this feeling. During a sprint or transition, the largest muscle in the calf contracts and increases in thickness to produce the force that propels the athlete forward. This change of state happens thousands of times during the game. For some, the repeated stretching of the muscles is enough to create a feeling of pressure when the sock constantly presses on the calf.
Over time, the practice of cutting holes in socks has taken on an almost accurate meaning among the players themselves: splitting open the fabric allows the muscles to “breathe,” relieving pressure and reducing the likelihood of pain or cramps. However, sports medicine and rehabilitation experts point out that there are no studies showing that cutting holes in socks provides any benefit. In fact, many studies on compression garments conclude that, if properly designed and fitted, they can help reduce muscle inflammation after intense exercise.
Despite the lack of evidence about the physical benefits, the practice continues to spread among professional soccer players. Today, it is considered to be the main thing that cannot be explained, based on the individual experience of each player rather than scientific evidence. In addition, the rules of the game do not prevent you from changing socks, as long as the equipment remains safe and the shin guards are always properly covered. (However, a football player cannot play with a torn jersey.)
Given the lack of scientific evidence, several experts believe that part of this phenomenon can be explained by the player’s own perception of comfort. In elite sports, the feeling of comfort can influence the confidence with which an athlete competes. If a soccer player believes that a piece of clothing is restrictive, removing that assumption can make him feel free to run, speed up, or change his gait—even if his performance remains the same.
Although there is no evidence that cutting socks provides a competitive advantage or reduces the risk of injury, that does not mean that the feeling of discomfort is imaginary. The perception of compression, restriction, or comfort depends on many factors, from the body composition and sensitivity of the individual to the athlete’s previous experience. In other words, two players may react differently while wearing the exact same clothes.
For now, it looks like the sock cut will continue. The available evidence points to a similar pattern to that of other sporting cultures: Its effect is primarily psychological, not necessarily physical.
This article originally appeared WIRED in Español and translated from Spanish.
