When we review running shoes, we often happen to mention something that may not be clear to everyone: the so-called “drop.” While explaining each time that it is the difference in height between heel and toe of the shoe, the question you may be asking yourself is legitimate: why should you care about this number? In fact, the topic may have the same appeal of the percentage of distribution of driving force between front and rear of a car: that is, something that 40 people in the world might find interesting, and 23 of them are Ferrari engineers (just kidding!).
The power of millimeters
The drops of running shoes vary from model to model in a range generally from 0 to 12 mm. Some shoes have no differential between heel and toe (drop 0) and others have it, more or less pronounced. Those with drop 0 are considered “minimal” or “natural” because they do not introduce any “non-natural” correction of foot strike. In fact, the barefoot rests both toe and heel at the same height on a flat surface. The more differential/drop there is, the more the shoe leads the runner to assume a “modified” running form.
Can a few millimeters make all that much difference? Yes: in this particular case it is useful to read this measurement not so much on the sole of the foot but rather on the length of the calf. The higher the heel (the more drop the shoe has), the “shorter” the calf will be, as it will be pushed upward into a position considered more relaxed or less extended.
How the drop changes the ride
Millimeters, as we have seen, also matter. The less drop, the lower and more taut the calf, and the more likely the runner is to land forefoot. You can test this by running barefoot: your brain will never command your feet to land on your heel because it knows full well how much pain this will cause you.
Conversely, if the calf is higher and relaxed one is inclined to land on the heel. This explains why running shoes have a lot of cushioning in the back: to cushion the impact of a part of the body that is not designed to land on the ground first, especially during running.
You might think now that natural running (with zero drop) is the right answer. This is not necessarily the case: if you have always run with some drop, changing habits involves at the very least a transitional phase during which your physique will have to re-educate itself and change its setting. The slightest discomfort you may experience is soreness in the calf, which will have to work (read: stretch) much harder than it used to. In more severe cases, however, more serious tears and trauma can occur. As usual, the advice is to approach such a radical change very gradually.
Mac vs. Windows
Remember years ago the very boring fight about which was the best operating system? Was it Apple or Microsoft? No one remembers how it ended, probably because neither was better in absolute value. The right answer, as is often the case, is: it depends.
If you have a well-trained foot and run naturally forefoot, you can use shoes with minimal or no drop.
If you have always been used to running with more or less pronounced drop and have never been injured, you might wonder why you would ever change. And it’s perfectly fine, I would be the first to tell you that there is no need to change.
If, on the other hand, you suffered more injuries attributable to the drop, you could try lowering it and, at the limit, canceling it.
Speaking from personal experience and having tried dozens and dozens of shoes with drops, I can also tell you that those who run forefoot and therefore with a “natural” setting, have never had a problem using shoes with even pronounced drops. At least that’s me: I run like that and I’ve never had any issue. Since I run only on the forefoot, the part of the shoe I use is the front part, which has essentially zero drop in any running shoe.
The drop that unites all
The “drop: yes or no” debate actually arose when the first natural or barefoot shoes appeared years ago: I’m talking about really extreme shoes for a select few, stuff with nonexistent drops and especially zero cushioning except for a few millimeters of rubber under the sole. It is clear that those who ran in such shoes without having an ultramarathoner’s foot would end up in orthopedics after a few kilometers.
Instead, for the past few years there has been a convergence of the market toward models that have features derived from both natural and traditional shoes. Today there are shoes with little or no drop but lots of cushioning (like the maximal ones) and “traditional” shoes with lower drops and wider toe boxes.
As is often the case, virtue lies in the middle, and the market has found its balance in models that have limited exaggeration in one direction or another by becoming viable alternatives for many different types of runners. Today we can finally choose from dozens and dozens of models: with drop, without drop, with little or a lot of cushioning, with wide or narrow sole and made of a thousand different materials.
If you can’t find the shoe that’s right for you, you certainly can’t blame the people who make them ;)