Rocker? End? Drop? What do these terms mean? Here’s a quick rundown of some common driving terms you might come across, both in this area and on roads and trails.

Midsole rocker: Many shoes today have a rocker where the midsole is up at the toe, heel, or both. The rockers encourage a smooth rolling motion for more efficient transitions from heel strike to toe-off, and help improve your economy and comfort.

Carbon/nylon plates: In recent years, we have seen more and more brands add the plates to their shoes. The primary role of a plate is to add stiffness, control, and dispersion to the soft, light, and fluffy foam of the shoe. Each brand adopts different designs, from spoon-shaped or footlong plates to winged plates. the Adidas Adizero Adios Pro ($250)for example, there’s what Adidas calls Energy Rods 2.0, which have a series of carbon rods under each toe to create a more flexible, natural ride. Plates are usually used in faster racing shoes or fast training shoes, but they are also found in shoes designed for cruising daily miles and trail running.

Energy return: The amount of bounce or spring that returns from the midsole from each foot strike. The more energy returned, the faster the trip. Faster shoes shoot for higher energy returns, but this can come at the cost of stability.

Stack height: This is the thickness of the midsole, measured from the ground to the footbed. You get two measurements, one for the heel and one for the forefoot. Higher stack heights generally provide more cushioning and shock absorption, while lower stack heights maintain better ground feel and stability. It also has to do with…

Drop: Also called heel-to-toe drop or offset, this is the difference between the heel and forefoot stack heights. Drops range from 0 to 12 millimeters, with most shoes being in the 6- to 10-millimeter size. Higher drop shoes transfer the impact of the heel, providing more recovery for heel strikers. Lower shoes promote a midfoot or forefoot strike, and tend to put pressure on the calf muscles. But be aware—and yes, I appreciate this is all a bit complicated—rockers can also change the effect of the drop.

Overpronation: When you overpronate, the foot rolls inward during running, putting more stress on the arch and inner foot. If you are new to running, go to a running specialist and ask for a treadmill test. They can detect whether you are over or underpronating, or running in neutral.

Underpronation: Sometimes called supination, the underpronator’s foot rolls outward. This reduces shock absorption and increases body weight.

Strength: Stability shoes provide additional support to under- or overpronators. Features such as lower stack heights, stronger midsoles, medial posts, or guide rails that align the foot, which help distribute the impact more evenly and reduce strain.