Denser (molded or injected) foam, TPU device, or combinations of the two, on the inside edge of the shoe’s heel to curb pronation and maintain the shoes integrity.

A soft polyurethane foam that conforms to the shape of the foot when warmed. Used in ankle collars and insoles.

The foam material layer that is found between the upper of the shoe and the outersole.

A shoe that has as much of the layers, overlays, and excess material removed and simplified as possible, to reduce weight and structure.

Founded in 1906 by brothers Rihachi and Rizo Mizuno, as a manufacturer of quality sporting goods. The brand expanded into running footwear in 1949 with a range of track spikes. The company set its running technology apart from other brands in 1996, with the Mizuno Waveplate, a corrugated thermoplastic plate embedded in the sole, and the introduction of the Waverider running shoe, now in its 25th iteration.

A shoe with components for curbing overpronation, often designed with a straight last for low arched to flat feet with hypermobile tendencies.

A description of the motion of the foot as it goes through the running gait cycle, unique to each person because of the complex variables and differences involved with their height, weight, strength, speed, leg length, foot size, fitness, etc. It also describes a shoe that does not hinder this motion.

The quintessential success story: boy travels the world, makes a gentleman’s agreement to sell running shoes – making up a company name on the spot (after a beer brand), invests effort and his own money, and gets startup investment from his track coach/partner. Coach develops new footwear technology and they found a new sports company. Now the world’s largest athletic footwear and apparel brand, currently led by an executive with roots in tech.

A technique which uses welded overlays instead of sewn, reducing the likelihood of irritating seams in the shoe’s upper, while lightening the weight of the shoe without compromising the support.

The tough material that contacts the ground at the bottom of the shoe. Usually made from a rubber compound, its thickness adds to the Stack Height of the shoe.

Supports, whether welded or sewn, that lend structure to the shoe, used in the heel, midfoot, and toe to secure the foot to the shoe and line it up over the midsole.

The slightly subjective measurement of eversion of the foot as it transitions from the heel touchdown to the toe-off during the gait cycle (see Pronation).

Lightweight CM-EVA, originally licensed from Mattel Toys. (Nike)

PU-based cushioning pad; registered trademark of Rogers Inc.

The natural motion of the foot to absorb shock, transitioning from the heel while lining up the big toe to push off toward the next stride.

Polyurethane, usually used in midsoles, insoles, and ankle collars.

One of two brands founded in Herzogenaurach, Germany, by the Dassler brothers. Puma is linked to Rudolph Dassler. A successful marketer, Rudy introduced footwear marketing strategies which are commonplace with athlete endorsers to this day. While not as inventive as his brother Adi, he had his own footwear craftsmen who produced an impressive array of running and track and field products.

The rear portion of the shoe that includes the heel. It connects to the vamp, and in running shoes is not a separate piece. It often features a piece of stiffer material called a counter (see heel counter) to keep the heel from moving from side to side.

Related to the shoe’s drop, it is the angle that the shoe pitches forward from heel to toe. It varies with each size and is more acute in smaller sizes, when there is any amount of drop to the shoe, for instance in a shoe with the same drop (approximately 10-12 millimeters in a typical shoe) a size 13 is going to have a smaller ramp angle than a size 7. A zero drop shoe would have no ramp angle.

The portion of the upper adjacent to the laces on each side to support the midfoot and keep it lined up over the midsole.

Footwear brand founded in 1898 by four businessmen in Kutztown, Pennsylvania. The factory was powered by the flowing water of Saucony creek, the origin of its name and logo. In the late 1960’s the brand was acquired by Hyde Athletic Industries, and moved to Cambridge, Massachusetts. Success of two of their running shoes strengthened the brand’s influence and by the 1980’s, Hyde became known as Saucony. Acquired again, in recent years, Saucony is presently a subsidiary of Wolverine Worldwide.

The portion of the shoe under the arch that is often supported by a TPU or nylon device to prevent the torsion of the foot from twisting the shoe and impairing its function. Most brands have a specific name for their version of the shank support, i.e. Torsion (adidas), Trusstic (ASICS), etc.

Vertical cuts in the sole of the shoe creating a grid-like pattern, freeing the flexibility of the sole and its effect on the foot’s natural motion, allowing for a fuller range of motion for the foot.

Shoe construction method which stitches the upper of the shoe that is slipped onto a last, closing the upper with stitches down the center, under the foot, before being adhered to the midsole.

The industry name for an OEM insole, and a term used interchangeably with “insole” to describe the layer that is directly beneath the foot in the shoe. Usually removable in a technical running shoe, it sits on top of the lasting board and provides a thin extra layer of cushioning to the shoe, but also adds extra thickness to the shoe’s stack height (see Stack Height).

A shoe which has a more supportive sidewall on the medial side of the shoe, splitting the difference between a Neutral shoe’s cushioning and a Motion Control shoe’s components for curbing pronation. The term motion stabilizing may be more accurate, as a shoe at rest is stable.

The height from the bottom of the shoe’s sole to the bottom of the foot in the shoe. This includes the outersole, midsole foam, lasting board and insole. The higher the stack height, the less proprioceptive feedback is received by the nerves in the foot. The thickness of the midsole adds what usually amounts to the largest portion of material in the shoe’s stack height.

Lower density rubber compound that has improved grip in wet or rocky conditions, but less abrasion resistance than harder rubber compounds.

A woven fabric which stretches a given amount to move with the foot, while still providing the necessary support and securing the foot over the midsole.

Shoe construction method which stitches a sole shaped fabric board to the upper of the shoe that is slipped onto a last, closing the upper with stitches around the perimeter of the sole. The board may be varied from thin flexible materials, thicker stable materials, or a combination of the two stitched together, to improve stability or flexibility.

A process which forces supercritical liquid nitrogen into a mold with a block of ethylene vinyl acetate. The pressure and nature of the liquid fills the spaces of the plastic and when the nitrogen gas escapes, its bubbles create foam with very stable walls within the plastic block which are both longer lasting and more lively than traditional EVA foam.

Running brand founded by athletic footwear executive Tony Post, with the name deriving from his college track team nickname To Po. The company was founded in 2013, launching a line of running and recovery footwear choices in succeeding seasons, arriving at their current 17 styles for running, walking, hiking, and recovery.

Thermoplastic urethane, often used in devices to prevent overpronation, as a lightweight outersole, for welded overlays, and for almost a decade as a durable palletized foam midsole.

Thermoplastic urethane, often used in devices to prevent overpronation, as a lightweight outersole, for welded overlays, and for almost a decade as a durable palletized foam midsole.

The portion of the vamp of the shoe that contains the toes, both in width as well as the height.

The natural spreading of the toes and forefoot when the bare foot contacts the ground. In a shoe this is restricted unless the toebox is wide enough to accommodate the width of the splayed toes, often described as a foot shaped forefoot.

The piece of fabric, and often times foam, that covers the instep of the foot under the shoes laces.

A shoe with a drop that is lower than a traditional shoe (usually less than 10 millimeters) but not as low as a zero drop shoe. They allow a runner to transition to an even lower Minimalist or Barefoot Inspired shoe, without over stressing muscle, tendon, ligament, or bone in the process.

The natural twisting forces of the foot as it transitions through the gait cycle.

A transitional compound between plastic and rubber. Frequently used as a poured midsole, as well as molded midsole processes, or for a variety of upper support thermoplastic applications. Often seen in pelletized form, compressed together to form the midsole.

The forward portion of the shoe’s upper that wraps from the arch around the toes to the cuboid bone. It surrounds the instep but does not include the tongue of the shoe.

A wide variety of specific rubber outersoles, each to manufacturer specifications, by the Vibram Corporation.

Outersole design, inspired by Nike co-founder Bill Bowerman’s attempt to pour polyurethane into a waffle iron to make the running shoe sole. The experiment ruined the waffle iron, and would have been indented instead of protruding, but ultimately resulted in an effective design featured on many millions of Nike shoes.

A shoe with the same stack height under both heel and toe.