Reference
Shoe & Foot Terms Glossary
Plain-language definitions for the terms used throughout this site — bookmark this if you keep running into unfamiliar jargon while reading our reviews and guides.
- Arch support
- A feature built into a shoe or insole meant to fill the space under your arch and reduce how much it flattens under weight. The amount of real support varies enormously between products despite the term being used loosely by almost every brand.
- Stability shoe
- A shoe built to gently guide the foot through a more controlled motion path, typically using firmer foam or external support structures along the inside of the midsole. Suited to mild-to-moderate overpronation.
- Motion-control shoe
- A firmer, more structured version of a stability shoe, built for more significant overpronation or higher body weight. Offers more correction than a stability shoe, at the cost of a stiffer ride.
- Neutral shoe
- A shoe with no built-in stability or motion-control features, designed for feet that don't need extra correction. Not typically recommended as a first choice for significant flat feet or overpronation.
- Overpronation
- Excess inward roll of the foot and ankle during walking or running, beyond what's considered an efficient amount of motion. Related to, but not the same as, having flat feet — see our guide on the difference.
- Supination (underpronation)
- The opposite of overpronation: the foot rolls outward rather than inward during motion. Less common than overpronation and usually associated with high, rigid arches rather than flat feet.
- Plantar fascia
- The band of connective tissue running along the bottom of the foot from the heel to the toes. Inflammation of this tissue is called plantar fasciitis, a diagnosable medical condition, not just a description of foot shape.
- Heel counter
- The firm cup at the back of a shoe that wraps around your heel. A stiffer, more supportive heel counter helps limit side-to-side heel motion, which matters for stability.
- Medial post
- A firmer wedge of material built into the inner (arch-side) edge of a shoe's midsole, used in some stability and motion-control shoes to resist excess inward roll.
- Midsole
- The cushioned layer between a shoe's outsole (the ground-contact layer) and its upper. Most of a shoe's cushioning and support technology lives here.
- Outsole
- The bottom layer of a shoe that contacts the ground, usually rubber, responsible for traction and durability.
- Last
- The foot-shaped mold a shoe is built around. Every brand, and often every model within a brand, uses its own last shape, which is the main reason the same labeled size can fit differently between shoes.
- Toe box
- The front portion of a shoe that surrounds your toes. A narrow toe box is a common complaint for flat feet, which often come with a wider forefoot.
- Drop (heel-to-toe drop)
- The height difference between the heel and forefoot of a shoe's midsole, usually measured in millimeters. A higher drop shifts more weight toward the heel; a lower drop feels flatter underfoot.
- Orthotic
- A supportive device worn inside a shoe to correct or accommodate a foot's shape or motion. Can be an over-the-counter insole or a custom device molded to your foot by a podiatrist.
- Mondopoint / CM sizing
- A sizing system based directly on foot length in centimeters or millimeters, rather than an arbitrary counting scale like US or UK sizing. See our size conversion chart for how it maps to other systems.
- Trim-to-fit
- An insole feature that includes printed size guidelines so you can cut it down to fit a specific shoe size, common on aftermarket insoles and orthotics.
- Rocker sole
- An outsole shape with a curved profile at the toe (and sometimes the heel) designed to help the foot roll through a step more naturally, often used in walking-focused shoes.
- Shoe volume
- The internal amount of space inside a shoe, not just its length and width. Two shoes labeled the same size can have very different volume, which matters when adding an insole or orthotic.
Looking for something specific? Check our best shoes for flat feet guide, our insoles guide, or the shoe size conversion chart.