The function of cushioning in running shoes is twofold: it serves to make you run more comfortably (a very welcome function, this) and to better protect your foot. The idea is that the more cushioned the shoe, the more the foot is protected. In short, the task of absorbing impact on the ground is left to the midsole and not to the joints and muscles of the foot and legs, or at least only partially.
Won’t it hurt?
Some researchers have wondered whether unloading the foot too much from its natural impact-absorbing function might be counterproductive: won’t it get badly accustomed to not exerting itself?
Instead, the results were surprising, so much so that they were called “counterintuitive” by Daniel Lieberman-one of the leading scholars of natural running. In fact, he himself assumed that the exact opposite happened only in barefoot running: the freer the foot is left, the more it will tend to fortify itself to let its muscles work harmoniously and absorb the efforts released during running. And it’s true: the foot muscles of barefoot (or “natural,” that is, with little or very little cushioning and not necessarily barefoot) runners are stronger because they have to work harder to absorb the shock of impact. What Lieberman did not expect, however, was that even a foot accustomed to a cushioned shoe could fortify itself. It seems to do the same, although for a different reason. To understand this, however, we must first understand how the foot works during running.
The arch
Approximately in the middle of your foot, on the sole and toward the inside is the so-called “arch of the foot.” When you put the sole of your foot on the ground, you can see it clearly because it is the only part that … does not rest! Not supporting, however, does not mean you are not working. In fact, one of its functions is to act like a spring: when the foot lands during running, it stretches to its fullest by charging up and then releasing energy when taking off. With each step you take it charges and discharges, incessantly. However, if much of the impact absorption is already absolved by the midsole what does he do? Are you going on vacation? Until Professor Kelly, who conducted this research on 16 candidates to whom were attached special cables capable of measuring the force expressed by the muscles of the sole of the foot, read the test results he would have said that was the case: those muscles were unloading. Instead, those of the candidates have shown that they work, and plenty. But not as those of natural runners work, but fortifying themselves to maintain balance. Since with cushioned shoes the surface on which the foot most directly impacts is that of the midsole, its muscles are activated to better maintain balance. It’s kind of like the brain convincing itself that you’re running on a very soft surface and therefore you need stability. This stability is achieved by increasing the strength of those muscles.
In essence.
The results obtained might suggest that there is no difference from a muscular point of view between natural and cushioned running, but they should be read differently: the difference is there, and at the same time a shoe with good protection does not “numb” the muscles of the sole of the foot. Only he does it for a reason that no one would have discovered if he had not had this insight.
So: if you use cushioned shoes, know that some effort your foot muscles do anyway. I tell you this to make you feel less guilty and also to make you realize that shoes help but they don’t run for you. But you already know that, considering that you struggle with it anyway, or don’t you?
(Via LA Times)