Why do running shoes have a drop?
Every shoe in Run Shoe Store—the largest selection of any Philadelphia-area running shoe store—has a drop. There are 7 drops currently (drops are measured in millimeters): 13mm, 12mm, 10mm, 8mm, 5mm, 4mm, and 3mm. That corresponds to .51 inches, .47 inches, .40 inches, .31 inches, .20 inches, .16 inches, and .12 inches. It seems that the drop of a running shoe is important.
More than 50 years ago, shoe manufacturers in the US were in the early days of sneaker manufacturing. Some of them were throwing together foams, rubber, cement, and nylon. Others were tearing apart shoes and recombining them in unexpected ways. A few of them were turning everyday appliances, like waffle irons, into shoe manufacturing devices. The group of them were making shoes through trial and error.
But they weren’t too interested in the drop of a running shoe, and their shoes didn’t usually have a drop.
The drop of a running shoe is important to racers
That changed around 45 years ago. Why? Because racers complained about the way no-drop shoes felt.
It’s helpful to remember that track athletes and road racers were the key—perhaps the only—demographic for running shoes. They were demanding customers because they did demanding things in their shoes.
Those runners were racing Marathons, not just participating in Marathons. They would train, not just run recreationally. These folks were accustomed to running many miles in their shoes, every week.
So the shoes had to be comfortable. At the very least, they couldn’t be so painful that they interfered with training and racing. So, those runners gave manufacturers a lot of feedback. And when the runners complained about ankle pains, manufacturers concluded that a heel in the shoe was called for. When the manufacturers then noticed that heel-area pain complaints were reduced—especially when Achilles tendon injuries were reduced—they took that as confirmation that the heel helped.
The drop of a running shoe may be important to non-racers, too
Most contemporary running shoe wearers don’t race. They don’t consider themselves runners-in-training. They run fewer miles at slower speeds than racers. But they also feel that the drop of a running shoe is important for comfort. Manufacturers have addressed them by giving a variety of drops.
Some people prefer no drop in their shoes. Manufacturers are making a small but growing number of no-drop shoes.
What is a drop?
Drop means that the distance from the ground to the heel of a shoe is higher than the distance from the ground to the forefoot of the same shoe. It means that the shoe has a heel. The foot standing on the shoe slopes downward from the heels to the toes.