Shoe Glossary

The difference in height between the heel and forefoot of a shoe, measured in millimetres. A 10mm drop means the heel sits 10mm higher than the ball of the foot. Higher drops (8–12mm) suit heel strikers and reduce Achilles strain; lower drops (0–4mm) encourage a midfoot or forefoot strike but require a gradual transition to avoid injury.

The total thickness of material between the foot and the ground at the heel, measured in millimetres. Stack height is the primary driver of cushioning — max-cushion shoes like the Hoka Bondi run 36–40mm; race flats sit at 20–28mm; barefoot shoes start below 10mm. Higher stacks absorb more impact but reduce ground feel and proprioception.

The stack height measured at the ball of the foot rather than the heel. Heel stack minus forefoot stack equals heel drop. For forefoot strikers who land at the front of the shoe, forefoot stack is the more meaningful cushioning metric — a shoe with a tall heel and thin forefoot provides little protection at the actual landing zone.

The natural inward rolling motion of the foot as weight transfers from heel to toe during a stride. Mild pronation is normal and helps absorb impact. Overpronation — excessive inward roll — can stress the ankle, knee, and hip over time and is the most common reason runners are recommended stability shoes.

When the foot rolls inward more than roughly 15° during the gait cycle. Most common in people with flat arches, it is associated with shin splints, plantar fasciitis, and knee pain under sustained mileage. Stability and motion-control shoes address overpronation through medial posting, guide rails, or denser inner-side foam.

When the foot rolls outward during landing, concentrating impact on the outer edge. Most common in people with high arches, supination creates pressure hotspots and can cause IT band and ankle stress. Neutral shoes with cushioning and flexibility are recommended — stability or motion-control shoes would restrict the foot in the wrong direction.

The part of the foot that first contacts the ground on each step. Heel striking is most common (~75% of recreational runners); midfoot striking distributes impact more evenly; forefoot striking shifts load to the calf and Achilles tendon. Shoe design — particularly heel drop and forefoot stack — should align with your natural strike pattern.

The shape of the inner arch when standing. Flat arches (low arch) tend toward overpronation; high arches tend toward supination; neutral arches fall between and fit the widest range of shoes. The wet foot test is a practical self-check: wet your foot, step on paper — a near-full footprint suggests flat arches, a narrow band suggests high arches.

A lab measurement of foam firmness using a Shore C durometer. Lower numbers mean softer foam: Hoka Clifton EVA tests around 20 HC; a traditional Brooks Ghost runs ~30 HC; racing PEBA foams can fall as low as 15 HC. Softer foam absorbs more impact but offers less stability and degrades faster. Heavier runners generally need firmer foam to prevent the midsole from bottoming out.

The percentage of impact energy that bounces back as forward propulsion, measured under lab conditions. Standard EVA returns about 55–65%; high-end PEBA foams return 80–87%; carbon-plated supershoes reach 85–89%. High energy return reduces fatigue on long runs but makes the shoe feel bouncier — some users prefer lower return for a more 'dead' feel in casual or recovery contexts.

Ethylene Vinyl Acetate — the standard midsole material in the vast majority of running and athletic shoes. EVA is lightweight, resilient, and affordable. It returns roughly 50–65% of impact energy and degrades gradually over 500–800km as the foam cells compress permanently. Premium EVA compounds (Nike React X, Brooks DNA Loft, ASICS FF Blast+) improve on base EVA with better durability and energy return.

Polyether Block Amide — a high-performance foam used in elite racing shoes from Nike (ZoomX), Adidas (Lightstrike Pro), ASICS (FF Turbo), and Saucony (PWRRUN PB). PEBA is softer, lighter, and returns significantly more energy than EVA (80–89% vs 55–65%). It is also more expensive and less durable, which is why it appears mainly in race-day shoes priced above $200.

A thin, stiff plate embedded in the midsole to stiffen the forefoot and amplify push-off. The plate works as a lever: it loads during the landing phase and releases during toe-off, channelling energy from the soft foam above it. Shoes with carbon plates improve running economy for most people but feel foreign initially and are not ideal for everyday training due to cost and reduced feel.

A sole curved from heel to toe — like the underside of a rocking chair — that promotes a smooth forward-rolling gait without requiring active toe push-off. Rocker soles reduce peak pressure on the metatarsals and Achilles, making them popular in max-cushion road shoes, healthcare clogs, and walking shoes. They can feel unstable to new users but significantly reduce joint stress over long periods on hard floors.

A 0–100 rating of the outsole's traction across a range of surfaces. Higher scores indicate better grip on both wet and dry terrain. Full rubber outsoles (Brooks blown rubber, ASICS AHAR) score 78–92; exposed foam pods score 65–75; deep-lug trail outsoles designed for mud score 85–95 on soft ground. Grip score is especially relevant for trail running, basketball, and work safety shoes.

A stiff internal or external structure at the back of the shoe that cradles the heel and controls rearfoot motion. Heel counter stiffness is rated 1–5: a firm counter (4–5) improves rearfoot stability for overpronators; a soft collar (1–2) prioritises comfort but offers less control. A very rigid counter can press on the Achilles tendon and aggravate tendinopathy in sensitive individuals.

A 0–100 rating of how well the shoe's upper allows airflow to reach the foot. Open-weave engineered mesh scores 75–85; closed synthetic uppers and leather score 30–55; Gore-Tex membranes score 25–40. Breathability matters most in gym training, high-intensity running, and hot climates. Lower breathability is acceptable in waterproof hiking boots where weather protection takes priority.

A 0–100 rating of how much the sole bends under force. High flexibility (75+) suits gym training, court sports, and natural-movement activities requiring lateral movement. Low flexibility (under 40) is deliberate in stability shoes, safety boots, and weightlifting shoes — rigidity is a feature in those contexts, not a flaw. SoleHunt penalises low flexibility only for gym-training category matches.

The internal width at the widest part of the toe box, measured in millimetres from physical lab samples. A wider toebox lets toes splay naturally, reducing blisters, black toenails, and bunion pressure. Regular-width feet typically fit 90–98mm well; wide feet need 98–105mm; extra-wide feet should look for 105mm+ or a 4E width option. Width mismatch is the most common cause of running shoe discomfort.

The vertical clearance inside the toe box, measured in millimetres. Most running shoes sit between 28–36mm; boots and safety shoes with protective toe caps reach 46–50mm. People with bunions, hammertoes, or high insteps benefit from more height (34mm+) as it reduces downward pressure on the toes. Road racing shoes often sacrifice height for a lower, more aerodynamic profile.

Standard letter codes for shoe width used by most North American brands. B is narrow (also women's standard), D is regular (also men's standard), 2E is wide, and 4E is extra-wide. Having multiple width options is uncommon and valuable — Brooks Ghost and New Balance 880 are among the few performance shoes available from B through 4E. Width availability varies by size and colourway, so always verify stock.

A shoe whose footbed is removable, leaving enough internal volume to accommodate a custom orthotic or aftermarket insole without crowding the foot. Orthotic-friendly designs typically have a deeper heel cup and a more neutral-volume upper. Note: adding a custom arch orthotic to an already motion-control shoe can over-correct and create new problems — orthotics usually pair best with neutral or mild stability shoes.

When a shoe fits as expected for its labelled size with no adjustment needed. Many shoes run a half-size small due to their last shape or a narrow upper. Trail shoes are often recommended half a size up to account for foot swelling during long efforts. SoleHunt's fit notes on each shoe are derived from aggregated reviews and brand guidance to flag sizing quirks before you buy.

The three-dimensional foot-shaped mould around which a shoe is built. The last determines the shoe's overall silhouette — straight lasts work better for flat feet, curved lasts suit high arches and supinators, and semi-curved lasts fit most feet. Two shoes with identical stated dimensions can feel completely different if they are built on different lasts, which is why trying shoes on (or reading detailed fit notes) still matters.

A road running shoe built for frequent, high-volume use — typically 4–6 runs per week across easy, moderate, and occasionally tempo paces. Daily trainers balance cushioning, durability, and weight. They differ from race shoes in that durability is prioritised over maximum energy return, making them significantly cheaper to run in per kilometre over a training cycle.

A running shoe with features that moderate excess pronation without fully blocking foot motion. Common approaches include a denser foam post on the medial (inner) side, guide rails embedded alongside the heel (Brooks), or a TPU plate under the arch. Stability shoes are the most commonly recommended shoe for mild to moderate overpronators with flat arches.

The most supportive category of running shoe, designed for severe overpronators and people with very flat feet. Motion-control shoes use rigid medial posts, firm midsole foam on the inner side, and stiff heel counters to significantly limit inward roll. They are heavier and less flexible than neutral or stability shoes but can be the difference between injury and sustainable running for the right person.

A shoe with no corrective features — uniform midsole hardness and no attempt to guide foot motion. Neutral shoes suit runners with neutral pronation or high arches who need freedom to move naturally. Most racing shoes are neutral. Putting a neutral shoe on a severe overpronator will not cause immediate harm but can contribute to cumulative stress injuries over many kilometres.

A shoe with an unusually high stack height (35mm+ at the heel) designed for maximum impact absorption. Popularised by Hoka, maximalist shoes reduce joint load during long-distance running and walking — popular with heavy runners, plantar fasciitis sufferers, and healthcare workers on hard floors. The high platform alters proprioception and can feel unstable initially.

A shoe with no height difference between heel and toe, placing the foot in a flat, near-natural position similar to barefoot. Zero-drop shoes (Altra, Vivobarefoot) encourage midfoot or forefoot striking and strengthen the intrinsic foot muscles over time. Transitioning too quickly from a high-drop shoe to zero drop is a common cause of Achilles and calf injury — a gradual 8–12 week transition is recommended.

SoleHunt's objective quality rating for a shoe, scored 0–100 independent of who is wearing it. It aggregates comfort, durability, performance, value, and fit data from lab measurements and expert reviews. CoreScore differs from Match Score — a shoe can have a modest CoreScore of 83 but rank #1 for you because its specific attributes align precisely with your foot type, use case, and budget.

SoleHunt's personalised fit rating, calculated by the Finder quiz engine across 9 biomechanics signals (category, width, cushioning, arch, budget, injury, durability, weight, drop). Unlike CoreScore, Match Score changes per user — the same shoe can score 94 for one runner and 61 for another. A high Match Score on a modest CoreScore shoe usually means it is the right choice for you specifically.