Running Shoe Overview What’s New, What’s Different, What to Know

Ana M. Cafengiu, DPM, ACFAS Fellow, AAPSM Introduction

Changes in world affected 2020 running shoe market

50% decrease in sales by April 2020

Then, marked increase in running shoe sales. More than 40% online.

34% increase in outdoor miles - March to September 2020

45% increase in race participation (virtual) - Spring to Fall Introduction

By 2021…

Running as “exercise of choice”

Move from gyms and health clubs to solitary running outdoors

Triple digit growth in road and trail categories

Higher demand for running technology Introduction

Current shift from traditional rating of running shoes based on LAST Neutral (underpronator, curved) Cushioned / Mild Stability (semi-curved) Stability / Motion control (overpronator, straight) Focus in 2021 is based on runner’s EXPERIENCE UNDERFOOT Softness, cushion (EVA) Energy, rebound (TPU) Speed (combo foam with nitrogen) Level of personalization — further broken down to neutral or support Introduction

Levels of personalization specific for each runner’s needs and which brand fills those needs.

Choosing the “right” shoe How does it fit? How does it feel? How does it ride?

Not always only one right shoe

slowtwitch.com Introduction

All major running shoe brands competing to create the fastest, lightest, most comfortable, energy-efficient shoe in the world.

The race is on! Objective

Brief history of running shoes

Anatomy of running shoe and terminology

Review key updates for 2021 in major running shoe brands

Obtain working knowledge of updates in order to make patient-specific recommendations in daily practice The Running Shoe: A Brief History

First pair 200 years ago - leather

1832 Walt Webster created Plimsoles

1852 Foster/Boulton Co. (Reebok) added spikes

After WW1 Increased popularity by Goodyear and Dunlop

1892 Rubber sole connected to canvas upper “sneakers” The Running Shoe: A Brief History

1920’s Modern running shoe design

Adolf Dassler -short distance (800m)

1948 Dassler Bros. founded Addas

1949 3 stripe design - support

1960’s NB Trackster - first in widths The Running Shoe: A Brief History

60’s-70’s Focus on enhanced traction, shock absorption and prevention of injuries

1970’s Running Boom

1974. Waffle trainer by Nike founder, Bill Bowerman

1976 NASA tech to create “air bags” into soles The Running Shoe: A Brief History

1980’s Focus on midsole technology Nike / Reebok / Adidas

Saucony Jazz Trainer

Adidas added pedometer

Asics silicone gel cushioning

1987. Nike Air Max - first visible air The Running Shoe: 21st Century

2004 Nike Free minimalist movement

2005 Barefoot minimalist

2006 iPod tech

2013 3D tech by New Balance

2015 Super light models (3 oz) The Running Shoe: 21st Century

2004 Nike Free minimalist movement

2005 Barefoot minimalist

2006 iPod tech

2013 3D tech by New Balance

2015 Super light models (3 oz) Anatomy of a Running Shoe Anatomy of a Running Shoe Run Shoe Terminology Heel to Toe Drop aka offset, differential The difference in height between heel and forefoot in an athletic shoe. Measured in mm.

Triactive.com Stack Height refers to amount of material between foot and ground runrepeat.com Heel to Toe Drop

Between 0 to 14mm in run shoe

Zero, Low 1-4, Med 5-8, High 8+

Go-to heel drop for average runner = 10mm NB Fresh Foam V10 Heel to Toe Drop Biomechanics

ALTRA Rivera 0 drop Salomon S/Lab Phantasm Brooks Adrenaline 12mm 6 mm Heel to Toe Drop Biomechanics

Lower drop Higher drop

Promotes forefoot /mid foot Promotes heel strike strike Loads hips and knees more Loads ankles and achilles Slower cadence Improved cadence May be helpful with PF, Achilles May be helpful with ITB, HS, and calf strain knee Increased knee flexion Increased ankle flexion with landing Midsole Materials - Foams

What is foam? a soft plastic filled with air bubbles All running shoe midsoles are made from closed cell foams.

EVA Ethylene Vinyl Acetate - most common, durable, heat or cold pressed, layers placed between outsole and footbed, range of densities and forms, soft but not responsive. Standard 1970-2010.

PE Polyethylene - made into sheets, cut and laminated, shaped as pads/tongues, waterproof, too soft for underfoot use

PU Polyurethane - foam blown into molds, liquid expands and foam air cells fill the molds, can be high density or low (insoles) Midsole Materials - Foams

Copolymers to create new foams (2010-2014)

TPE Thermoplastic elastomer - copolymer that acts as a rubber but processed like plastic, versatile, stable, good rebound

TPU Thermoplastic polyurethane - subset of PU, can be re-molded after solid, blown into molds, durable, heat resistant

Pebax Thermoplastic elastomer (Polyether block amide) used as foam or plates, high performance, super light, low energy loss, Nike ZoomX PEBAX What is it? Block copolymer technology: 2 different compounds on same polymer chain Retains performance properties of both.

Polyether blocks Polyamide blocks Flexible Lightness Elastic Strength Energy return

By changing ratios of blocks and chain lengths, can tailor final polymer to be balanced based on final goal of product. Midsole Innovation Innovation of new foams gives advantage of both Plush Cushioning and Energetic Rebound

Nike ZoomX -special form of Pebax Adidas Boost / Ultraboost

NB Fresh FoamX, Fuel Cell Saucony PWRRUN Foam

Brooks DNA AMP, Zero, Flash, Asics Flytefoam Blast Hoka RMAT, ProFly Mizuno Enerzy Core Altra Ego Under Armour HOVR On Helion Li-Ning Pebax (new co.) Reebok FloatRide -Pebax based Carbon Fiber Plate

Reduces energy loss caused by bend at MTPJ during propulsion

Curvature of plate creates reaction force at heel to propel runner forward

Not new concept but popularized by Nike Vaporfly 4% Breaking 2

From research by Stefanyshin and Nigg Willwacher, and Hoogkamer The Rise of the Super Shoes Nike AlphaFly Next%

Saucony Endorphin Pro

Brooks Hyperion Elite

Adidas Adizero Pro

New Balance Fuel Cell RC Elite

Asics Metaracer

Hoka Rocket X, Carbon X, Carbon Rocket

Skechers GoRun Speed Elite Hyper Nike Vaporfly Next% “The fastest shoe on Earth”

STATS: In last 2 years

31of 36 wins in 6 major marathons

Both men and women marathon record breakers

Controversial as “a form of “mechanical doping” and too much of an advantage

No longer banned from 2021 Olympics decision by World Athletics. Stricter regulations: only 40mm, 1 plate Nike Vaporfly Next%

COMPONENTS

Full length carbon plate

ZoomX wide forefoot midsole

Deep longitudinal grooves in outsole

Ultra-light Vaporweave upper

8mm heel drop Nike ZoomX Vaporfly Next% 2

Advanced version of Vaporfly New engineered mesh upper with padded tongue Forefoot reinforcement Single carbon plate 40mm stack height 8mm heel drop “Returns 85% of energy back” Nike Air Zoom Alphafly Next%

Slightly heavier than Vaporfly but increased foam for more cushion

New atomknit upper

Full ZoomX midsole with single plate

Added Zoom Air pods side-by-side (just below plate and above outsole)

40mm height, 8mm heel offset

2021 Summer Olympics Legal Nike ZoomX Invincible Run

Lightest and bounciest on market described as “pogo stick on trampoline”

First with full length ZoomX midsole, and no plate

Comfortable knit upper

Neutral for long, slow miles with 9mm drop

Durability uncertain Nike React Infinity Run Flyknit 2

Updated Flyknit, improved secure fit, padded collar

More stable than Invincible but less speed, high stack with soft foam

Increased durability

Heel-Toe drop 8.8 women, 7mm men

Mainly for long, easy recovery runs Nike Air Zoom Tempo Next%

“Everyday version of Alphafly Next% For tempo runs only

Replaces the Pegasus Turbo2

2 types of midsole foam, Zoom React back and ZoomX front, air pods, and plate

46mm heel stack, 10mm drop

Good for heel strikers New Balance Fuel Cell

Nitrogen infused TPU and full length carbon plate

High energy return (min 55%)

Fuel Cell TC (training & comp)

Fuel Cell RC Elite (racing & comp) Fuel Cell TC New Balance Fuel Cell RC Elite

Race shoe inspired by NB’s 5280

“The lightest density made with the most energy return”

2 mm less foam in heel and forefoot

Lower stack height good for shorter races too

Lighter than Endorphin Pro, Alpha Fly, Adizero Pro NB Fuel Cell Rebel 2

Lightweight daily trainer for tempo

Highest rebound fuelcell midsole

Softer, livelier, energetic version without plate, NDURANCE rubber sole in impact areas, offset lacing

26mm heel, 6mm drop,

Great reviews all around - feels like RC Elite, “trampoline -like” New Balance Fresh Foam 1080

Top of the line neutral with Fresh FoamX

Hypoknit upper with zonal stretch

Redesigned laser engraved midsole

Updated ultraheel

8mm drop New Balance Fresh Foam More V3

Super cushioned and lightweight maximalist shoe, competitor to Hoka Bondi

Both soft and quick

For daily high mileage, ultras

30mm heel height, 4mm drop

Heel cup with internal heel pods for locked-in feel New Balance Fresh Foam Vongo V4

Maximum Stability Shoe with cushion

Redesigned laser engineered midsole with varus wedge, no needed post

3D printed upper mesh, sock-fit collar

29mm heel stack, 4mm drop

Wide fit, good for overpronators New Balance Neutrals

6mm drop

FUEL CELL REBEL v2 (intro mid April) 10mm drop FRESH FOAM 880 V11 (Workhorse)

8mm drop

FRESH FOAM 1080 V11 (Top of the line) 4mm drop

FRESH FOAM MORE V2 (competitor to Hoka) New Balance Fresh Foam Tempo

Light weight trainer replaced Fresh Foam Zante

Brand new Fresh Foam X midsole, upper outsole, and external plastic heel counter

Rubber on RF and FF, not on midfoot

Short and mid distances

6mm heel drop (same as Zante) New Balance Tech: FreshFoamX

Fresh FoamX laser engraved and lighter than Fresh Foam

Data from thousands of runners to match natural flex patterns

Laser engraving to alter levels of compression

Convex and concave sidewall patterns as needed for neutral or stability shoe New Balance Tech: Fuel Cell

“To help runners find their fast”

Microanalysis of biomechanics from actual athletes down to 1/10 of second

Identified 3 key areas to improve; Impact, Pivot, Take-off

Data used to optimize shoes for support, shape, and efficiency - all at speed Brooks Hyperion Elite 2

Updated with new midsole foam, designed for 1-2 marathons

DNA Flash with carbon plate

Higher heel stack, wider base, good mix of cushion and energy so best for long, fast runs

Unisex shoe, 7.6oz (size 9) 8mm heel drop Brooks Hyperion Tempo

Great as lightweight trainer / racer

DNA flash, nitrogen infused foam, No carbon plate

Good as “gym shoe”

Neutral, 8mm heel drop Brooks Glycerin 19

Updated full length 100% DNA Loft Midsole, soft and responsive

New sock-like double jacquard upper, breathable, cool, dry

Smooth, consistent ride

Neutral with inherent stability due to wider footprint and midsole structure, flared outsole Brooks Glycerin Comparisons Brooks Glycerin and Launch GTS Brooks Levels of Personalization

Based more on runner feel or experience and desire of goal set Brooks Material / Tech

CUSHION / SOFT FEEL

DNA Loft - soft cushion DNA Amp - bouncy cushion Biomogo DNA - adaptive cushioning, environmentally friendly DNA Flash - nitrogen infused, super lightweight, responsive Brooks Material / Tech

STABILITY / SUPPORT STRUCTURES

Guiderails- medial and lateral Arch Pods - Passive support to support to limit increase stability without a post calcaneal eversion and shifting Pivot post - stabilizes suspension Extended PDRB (PROGRESSIVE on both side of foot DIAGONAL ROLL BAR) Brooks tech based on Run Signature - research looks at knee to determine how to reduce injury rate Hoka One One Mach 4

Long-distance trainer Lightweight, great cushion 29 mm heel height 5mm drop Neutral High ratings among reviewers as “best update for 2021" Hoka One One Mach 4 Hoka One One CarbonX2

New midsole foam CMEVA More foam, less weight Softer feel, more energy return Carbon plate moved plantar Improved upper, tighter fit Taller heel cap, softer heel pad Swallow-tail heel design to transfer heel-roll to forefoot Hoka One One RocketX

Best for short intervals / races Less roll effect than CarbonX2 Stable ride, not as soft 1mm plate centered at midfoot EVA midsole with less propulsion, lower energy return Asics EvoRide 2

Versatile trainer for both tempo and longer distance runs

New thicker, softer full-length Flytefoam midsole

Forefoot rocker uses GuideSole tech

Improved outsole with AHARP+ and engineered mesh upper

Best for neutral or supinators

Heel drop 5mm Asics MetaRacer Tokyo

First carbon fiber shoe for Asics, limited edition for Olympics

Rocker-style midsole more cushion in heel than FF

Aggressive toe spring carbon plate further from foot

Lower heel stack racer, 24 mm.

Heel drop 9mm Adidas Adizero Adios Pro

Flagship racing shoe with rocker Race day shoe foe 1/2 or full Softer, bouncier than Adizero Pro Midsole mix of Lightstrike Pro foam Carbon heel plate and Energyrods in midsole limits energy loss Celermesh upper- lightest yet Heel stack 39mm, Drop 8.5mm Adidas Ultraboost 21

Reliable workhorse trainer 6% more Boost in midsole Redesigned LEP Torsion adds stiffness, more responsive Sustainable upper PRIMEBLUE 50% recycled ocean plastic Hefty weight for trainer 12oz. 30.5 heel height, 10mm drop Saucony Endorphin Pro

Top tier marathon racer of trio including models Speed and Shift Minimalist fit and feel, PWRRUN PB foam S shaped carbon plate “Speedroll effect” Removable sock liner, no-seams mesh Responsive ride, great energy return Heel height 35.5mm, Drop 8mm Saucony Kinvara 12

Racer that can also be daily trainer Lighter, more flexible than past Firm and more responsive, new mix of Pwrrun foam Good for speed and longer distance Some mild stability components Heel 28.5mm, Drop 4mm Dovetail heel Altra Rivera (New)

A cross btw daily trainer and racing flat (rep Torin Mesh) Ultralight, thick Ego midsole More ground feel , less outsole Streamlined last, sock-like fit, but same foot shaped toe box Zero drop Reebok FloatRide Run Fast 2

New version more performance trainer than racer Aggressive toe spring Light and bouncy FloatRide and EVA midsole Full-length durable rubber sole 1 oz. heavier than first Heel Drop 8mm On Cloudflow

Lightweight performance shoe Balance of cushion and response Good for training and racing Super flexible, full-length groove Brand’s own Helion foam and Hollow pods (9 on each side) Heel drop 6mm Conclusion

Innovation in running shoe design and materials with focus to Improve efficiency and performance. Prevent injury. Provide customizable feel and experience. Speed recovery. Midsole design Ulltra-lightweight, responsive, high rebound foams Mainly neutral with intrinsic reinforcement Carbon fiber plate to increase efficiency and decrease fatigue

Engineered and 3D printed uppers and heel counters Lightweight, breathable and supportive Thank You

“Only those who will risk going too far, can possibly find out how far one can go.” - T.S. Eliot