Rocker? Last? Drop? What do these terms mean? Here’s a quick rundown of some common running terms you may encounter, both in this article and on the roads and trails.
Midsole rocker: Many shoes now feature a rocker where the midsole slopes upward at the toe, heel, or both. Rockers encourage a smooth rolling motion for more efficient transitions from heel strike to toe, and can help improve both economy and comfort when running.
Carbon/nylon plates: In recent years, we have seen more and more brands adding plates to their shoes. The primary function of a plate is to add rigidity, control and elasticity to the soft, lightweight and elastic foam of the shoe. Each brand adopts different designs, from spoon-shaped or foot-long plates to winged plates. He Adidas Adizero Adios Pro ($250)For example, they have what Adidas calls Energy Rods 2.0, with a series of carbon rods under each toe in an attempt to create a more flexible and natural ride. Plates are most often used in faster racing shoes or fast training shoes, but they have also appeared in shoes designed for daily mileage and trail running.
Energy return: The amount of bounce or spring that returns from the midsole with each foot strike. The more energy returned, the more bouncy the ride will be. Faster shoes aim for greater energy return, but this can come at the cost of stability.
Pile height: This is the thickness of the midsole, measured from the ground to the insole. You get two measurements, one in the heel and one in the forefoot. Higher stack heights generally provide greater cushioning and shock absorption, while lower stack heights retain better ground feel and stability. This is also related to…
Drop: Also called heel-to-toe drop or offset, this is the difference between the heights of the heel and forefoot. Drops range from 0 to 12 millimeters, with most shoes falling in the 6 to 10 millimeter range. Shoes with a higher drop transfer the impact to the heel, offering more cushioning for heel strikers. Lower drop shoes promote a midfoot or forefoot strike and tend to put more pressure on the calf muscles. But keep in mind (and yes, I understand this all sounds a little complicated) that rockers can also alter the impact of the drop.
Overpronation: If you overpronate, your foot turns excessively inward during running, which puts additional stress on the arch and inside of the foot. If you are new to running, go to a running specialist and ask for a tape assessment. They will be able to see if you are overpronating or underpronating, or if you are running neutrally.
Underpronation: Sometimes called supination, an underpronator’s foot turns outward. This can reduce shock absorption and put more pressure on the body.
Stability: Stability shoes offer more support to underpronators or overpronators. Features like lower stack heights, firmer midsoles, medial posts or guide rails align the foot, helping to distribute impact more evenly and reduce strain.