A technical glossary of running shoe terms
The language of running shoes
The world of running shoes can be a confusing one and buying the right pair to suit your particular running style is vital. Here's the realbuzz ultimate guide to demystifying all those complex running shoe terms. You can use this as reference tool whenever you come up against a running shoe-related phrase you're not sure of.
Achilles tendon pad: A lining inside the heel area of the upper, designed to cushion and protect the achilles tendon.
Adjustable width lacing: A system of webbing loops or rings to secure the lacing of the upper used in place of eyelets; also referred to as ‘speed’ lacing.
Aglet: The plastic tip at the end of a shoelace.
Anatomical sock liner: Moulded to support the entire foot like a custom built orthotic.
Arch bandage: Reinforcing strips of fabric stitched inside the midfoot upper in Reebok shoes.
Bellow tongue: A stitched-in tongue, giving protection from the elements and the ingress of debris.
Blown PU: Used in the outsole; PU foam impregnated with air for lightness, flexibility and cushioning. More durable than blown rubber, with no sacrifice in traction.
Blown rubber: Foamed rubber (rubber with intrinsic air cells) to reduce weight; used as lightweight outsole material.
Board last: A fibreboard (thick, stiff, paper-like) material to which an upper is glued during manufacturing to create a 'bootie' to which the midsole can be glued.
Board lasted: The upper section is pulled over the last and cemented to a flexible innersole board. This method provides stability and is especially good for larger individuals.
Cambrelle: A lining material with breathability and moisture wicking properties.
Carbon rubber: Where carbon is added to the outsole compound to increase durability of the rubber.
Collar: The padded material used around the top of the heel area of the upper for extra support and comfort.
Combination lasted: A construction technique where the rearfoot is board lasted for stability and the forefoot slip lasted for flexibility.
Compression molded EVA: Midsole construction consisting of ethyl vinyl acetate foam that has been heated and compressed to give it shape and improve durability.
Coolmax: DuPont fiber used in shoe linings, which helps to keep the foot cool and comfortable by wicking away moisture.
Cupsole: An outsole construction, which cups the midsole to give greater lateral support and stability. Can be 'twin' (heel and toe cupped), or 'three quarter (medial arch area open).
Cushioning: The act of absorbing energy when the foot strikes the ground, by decelerating the foot over the distance the midsole compresses.
Dual density midsole: Midsole constructed with foam of two different densities or stiffness, such as 'rim and core' construction, in which softer foam is in the center (core) and harder foam around the edge (rim) of the middle, for greater comfort and stability.
3D Ultralite: Foam based rubber compound. A unique one piece mid/outsole construction that helps to reduce weight, 3D Ultralite is molded through expansion at very high temperatures. It is both lightweight and extremely durable.
Eco-grip rubber: A rubber compound composed of 30 per cent recycled rubber gloves.
Energy efficiency: Ratio of the amount of energy returned by a material to the amount of energy absorbed; greater efficiency means more energy is returned to the foot by a midsole.
EVA (ethyl vinyl acetate): A blown microcellular midsole material, which is lighter and more flexible than rubber.
Flex groove: Grooved outsole/midsole construction in the forefoot, which allows the shoe to bend with the foot's natural flex region while still providing cushioning.
Footframe: A molded PU frame sitting on top of the midsole to cradle the foot, increasing support and flexibility and preventing 'roll-out'.
Foxing: Suede reinforcement on a shoe, giving medial and lateral support to the foot.
Full grain leather: A resilient, supple material that gives excellent wear and durability.
Garment leather: Very soft leather pioneered in performance shoes by Reebok.
Graphlite: A lightweight, strong, and durable graphlite component that helps to reduce the overall weight of the shoe and provides support.
Gum rubber: A rubber compound with a high percentage of natural rubber, giving excellent durability and traction.
Heel counter: Plastic or fibreboard piece in the heel of the upper helps keep the heel centred over the midsole.
Hexalite: Lightweight honeycomb material originally developed for the aerospace industry. Absorbs 25 per cent more energy than the equivalent amount of EVA foam. Provides shock absorption in high impact areas.
Injection-molded EVA: The process by which ethylene vinyl acetate foam is injected into moulds, making it more uniform and durable. As it continues to expand after the injecting process, it must be closely monitored.
Inner fit system: A component of the upper designed to give a 'sock-like' fit.
Lace locks: Thermo polyurethane eyelets to secure laces.
Last: The foot form, usually wood, metal or plastic onto which the shoe is built.
Lasting methods: Lasting is the process of stretching a stitched shoe upper around a last so that a midsole and outsole can be attached. There are four types of last.
- Slip last: The upper is stitched together, but there is a board in the rearfoot to improve rearfoot stability.
- Three part board last: Board last with a section of woven material stitched into the forefoot for improved flexibility.
- Stroble stitched last: The upper is stitched at the boarder to a flexible, woven material, rather than glued to fibreboard.
- Combination lasted: A construction technique where the rearfoot is board lasted for stability and the forefoot slip lasted for flexibility.
Meta-flex hinge: Grooved outsole/midsole construction in the forefoot which allows the shoes to bend with the foot's natural flex region, while still providing cushioning.
Midsole: Cushions the foot and plays a key role in controlling excess foot motion. It is located between the upper and the outsole and is attached to both.
Millithane heel plug: Lightweight, durable outsole material.
Motion control: The ability of a shoe to control the degree of mobility in the gait cycle; also may refer to the specific features of a shoe that aid in this control.
Notched heel tab: Provides a secure fit without irritating the achilles tendon.
Nubuck: Full-grain leather buckskin.
Nylex lining: High abrasion nylon.
Orthotic: A corrective device, primarily made of leather and/or plastic, placed inside an athletic shoe to help correct biomechanical problems; usually prescribed under the direction of a podiatrist.
Outsole: The bottom portion of a shoe that provides traction and resistance to wear.
Outrigger: A lateral extension to the outsole to provide a stability platform.
Overlays: Support straps built into the shoe upper.
Overpronation: When the foot rolls too far inward when the foot hits the ground. Excessive pronation can lead to a variety of injuries, including runners’ knee, tendonitis, and bursitis.
Pebax spike plate: Extremely tough injection molded plastic receptacle which holds the spikes in the forefoot of the racing shoes.
Pivot point: A circle shaped part of the tread located at the ball of the foot that allows for easier turns and twists.
Power strap: Strap that crosses the top of the midfoot to secure the foot in the shoe during abrupt stops and starts.
Pronation: The inward (medial) roll of the foot, and in particular the heel and arch which occurs naturally at heel strike as a cushioning mechanism; potentially injurious if excessive or abrupt.
PU (polyurethane) foam: Most durable, but also heaviest of the midsole cushioning materials, a very durable, but flexible plastic.
PVC: Polyvinyl chloride: A semi-rigid plastic with strength attributes, used in a variety of components, particularly heel counters.
Randing: Strip that runs around the welt of the shoe to resist water penetration.
Rearfoot support structure: Stiffening piece on the medial side (inside) of the midsole, under the heel; provides pronation control without sacrificing cushioning.
Rim and core: Construction technique for midsole; typically a five to 10 millimetres thick edge (rim) of higher density foam, compression molded around a slightly softer (low-density) center (core) of foam.
Scotchlite: Reflective material used as trim to increase visibility of running shoes.
Shock absorption: Cushioning, the act of absorbing the energy of an impact.
Skeletal outsole: Outsole with much of the heavy rubber removed, covering midsole only as necessary to preserve durability and traction; more lightweight than conventional outsoles.
Sockliner: The inner footbed of EVA, Peeva, PU or latex sponge rubber. Improves in-shoe comfort and shock absorption.
Stability pad/platform: A lateral or medial extension area of the outsole with minimum profile for stability.
Steel shank: Thin steel strip in the midsole of the shoe, extending from behind the toes to under the heel. Provides stiffness and protects against sharp surface irregularities; typically used in hiking boots.
Straight lasted: Where the last is very straight on the medial side to increase stability on cases of severe overpronation.
Synthetic leathers: Filskin and Kinbuck. Reebok uses high quality synthetic leathers on their performance running and squash shoes because of their lightness, strength, durability, non-stretch and abrasion resistance properties. Also their water retention is much lower than leather and suede.
Supination: Opposite of pronation; the outward rotation of the foot or ankle in movement.
Thermoplastic heel counter: PVC molded under heat and pressure to give strength and support in the heel of the shoe.
Toe box: Plastic or fibreboard piece in the toe of the upper to maintain shape and improve durability in the toe.
TPU: Thermo polyurethane; strong, durable and flexible.
TPVR weld: Urethane-based themoplaster reinforcements welded to the fabric of the upper, eliminating the need for heavier overlays.
Tumbled leather: A leather grain achieved during the finishing process; not embossed.
Upper: The leather and synthetic portion of the shoe which covers and fits to the foot, holding the foot onto the midsole.
Vamp: The forepart upper of the shoe.
Vulcanization: A process of treating a material at high temperatures to increase the strength and the elasticity of the compound.