Running Shoe Overview - What's New, What's Different, What to Know Ana M. Cafengiu, DPM, ACFAS Fellow, AAPSM - The Goldfarb Foundation

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“TheVaporfly         Next%
                     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