Definition

Minimalist shoes are footwear providing minimal interference with the natural movement of the foot due to its high flexibility, low heel to toe drop, weight and stack height, and the absence of motion control and stability devices.

As part of a study led by researchers from Laval University, 42 experts from 11 countries defined minimalist shoes and built the Minimalist Index. The following experts actively participated in the process which included 4 rounds of questions. To access the open-access full version of the article published in the Journal of Foot and Ankle Research, follow this link.

Criteria

  • Flexibility

    The shoe is tested for longitudinal (forward part of the shoe is bent up) and torsional (forward part of the shoe is torsioned towards pronation) flexibility. The more flexibility, the higher the score on this subscale.

  • Weight

    Simply put the shoe on a scale. The lighter the shoe, the higher the rating on this subscale of the Minimalist Index.

  • Stack height

    Measured at the center of the heel, stack height evaluates the distance between where your foot sits and the most external part of the outsole underneath. The thinner the shoe, the higher the score on the stack height subscale.

  • Stability and Motion control technologies

    Simply identify the most commonly used technologies in running shoes to control pronation. The least amount of technologies in your shoe means that the Minimalist Index will be higher.

  • Heel to toe drop

    The drop is the difference between shoe thickness under the heel and where your toes start. The closer to 0, the higher the rating on the Minimalist Index.

Calculate

Weight

Place shoe on the scale. According to the scale, what is the weight of the shoe (in grams)?

Heel Thickness

Using a digital caliper, measure the height of the shoe at the heel (including insole, midsole and outsole). The caliper must be placed at the middle of the heel when looking at the shoe from the rear end, and in the middle of the heel when looking at the shoe from the side.

Caution must be taken when placing the caliper on the outsole, as the most external (thickest) point of the shoe has to be considered.

The caliper must be placed at the middle of the shoe when looking from the rear end.

The caliper must be placed at the middle of the heel when looking from the side

Heel to Toe Drop

Using a digital caliper, measure the height of the shoe at the metatarsal heads (including insole, midsole and outsole). The caliper must be placed at the middle of the shoe when looking at the shoe from the top. Caution must be taken when placing the caliper on the outsole, as the most external (thickest) point of the shoe has to be considered.

Now, substract the height at the metatarsal heads from the stack height to obtain the heel to toe drop.

The caliper must be placed under the metatarsal heads

The caliper must be placed at the middle of the shoe when looking from the top

 

Motion Control and Stability Technologies

Among these technologies, which ones can you observe on the shoe?

  • Multi-density midsole: Typically, a different color is used to emphasize this feature.

  • Thermoplastic medial post. Plastic is used to reinforce the medial portion of midsole.

  • Rigid heel counter.

  • Elevated medial insole under arch (left), compared with a flat insole (right).

  • Supportive tensioned medial upper. Material is used to reinforce medial upper in order to limit medial foot movement.

  • Medial flare. Medial tip of midsole extends beyond footbed.

Longitudinal Flexibility

Using a pinch grip with thumb, index and middle fingers from both hands, apply a superiorly-directed force to the anterior and posterior parts of the shoe. See images below to determine appropriate rating.

Select longitudinal flexibility.

5/5

Minimal resistance to longitudinal bending (the shoe can be rolled on itself more than 360 degrees)

4/5

Slight resistance to longitudinal bending (anterior tip of shoe sole reaches posterior tip of shoe sole in a maximal bending of 360 degrees)

3/5

Moderate resistance to longitudinal bending (anterior tip of shoe sole doesn't reach posterior tip of shoe sole, but anterior and posterior parts of the shoe can form an angle of at least 90 degrees)

2/5

High resistance to longitudinal bending (anterior and posterior parts of the shoe can form an angle between 45 and 90 degrees)

1/5

Very high resistance to longitudinal bending (longitudinal deformation is possible, but anterior and posterior parts of the shoe form a maximum angle of 45 degrees)

0/5

Extreme resistance to longitudinal bending (longitudinal forces don't significantly change the orientation of the anterior part of the shoe relative to the posterior part)

Torsional Flexibility

Using a pinch grip with thumb, index and middle fingers from both hands, apply a medially-directed torsional force (pronation) to the anterior part of the shoe. See images below to determine appropriate rating.

Select torsional flexibility.

5/5

Minimal resistance to torsion (anterior part of the shoe is turned 360 degrees; anterior outsole faces inferiorly after a complete twist while posterior outsole faces inferiorly)

4/5

Slight resistance to torsion (anterior part of the shoe is turned at least 180 degrees but less than 360 degrees; anterior outsole faces at least superiorly while posterior outsole faces inferiorly)

3/5

Moderate resistance to torsion (anterior part of the shoe is turned more than 90 degrees but less than 180 degrees; anterior outsole faces at least laterally while posterior outsole faces inferiorly)

2/5

High resistance to torsion (anterior part of the shoe is turned more than 45 degrees but less than 90 degrees; anterior outsole can't face laterally while posterior outsole faces inferiorly)

1/5

Very high resistance to torsion (torsional deformation is possible, but anterior part of the shoe reaches less than 45 degrees

0/5

Extreme resistance to torsion (torsional forces don't significantly change the orientation of the anterior part of the shoe relative to the posterior part)

Applications

Switching to new shoes ?

Consider the Minimalist Index to plan your transition! Switching from one model to another may lead to injury when done too quickly. Runners should aim for 1 month of transition time for every 10% change in the Minimalist Index score. Thus, you should plan a 2-month transition period when switching from shoes rated 50% to others rated 70%. This rule of thumb is conservative, but applicable to the majority of runners.

Depending on your habits and your tolerance to change, you may require more time or even less time to transition. Too quick of a transition towards a more minimalist shoe (higher score on the Minimalist Index) will typically result in symptoms to your foot, Achilles tendon or calf muscle. On the opposite, too quick of a transition towards a more maximalist shoe (lower score on the Minimalist Index) will typically cause symptoms to your knee, hip or lower back… simply because different shoes load different tissues of your body differently. In the end, everything is a matter of adaptation! Listen to your body!

Willing to change your running mechanics ?

Select the appropriate shoe category! Several studies have suggested that runners tend to automatically modify their running mechanics depending on the shoes they are wearing. The more minimalist the shoe, the higher the probability to increase impact-moderating behaviors. As a means to protect the body from the impact, many changes will occur such as increased step frequency and decreased dorsiflexion at the ankle, with a tendency for a forefoot strike pattern.

These modifications in the running gait pattern will reduce loads applied at the knee, hip and lower back. The higher the Minimalist Index score, the higher the probability of such changes… and since these changes are automatically brought upon by more minimalist shoes, they may be more durable on the long-term than voluntary changes to your technique. And please, do not restrict the definition of minimalism only to the heel to toe drop, which is a characteristic with only little influence on running mechanics. Consider the whole Minimalist Index!

You are a researcher ?

Rate the shoes you are testing with the Minimalist Index, which is a valid and reliable tool that was built with the help of 42 renowned experts around the world!

The words “Minimalist” and “Maximalist” are widely used to promote or sell different footwear models. Shoes could be completely different yet they could be included within the same category. In addition, specific characteristics may be associated with shoe categories depending on market trends, although they simply represent one aspect of the shoe. As an example, heel to toe drop is often taken as the best descriptor of minimalism shoes; however, the isolated effect of drop on running kinematics is not that convincing.

Thus, it is misleading to generalize the effects of minimalist or maximalist shoes on running mechanics or injuries without considering quantitative measures of a number of characteristics, as shoes from the same category can differ widely. Including all those aspects will definitely help in understanding the effects of footwear on running mechanics and in developing clinical guidelines for transition between different footwear.

The experts

As part of a study led by researchers from Laval University, 42 experts from 11 countries defined minimalist shoes and built the Minimalist Index. The following experts actively participated in the process which included 4 rounds of questions.

To access the open-access full version of the article published in the Journal of Foot and Ankle Research, click here.

Experts

  • Ian Adamson

    M.Sc, M.Eng.

    Healthy Runnning,

    United States

  • Shawn W. Allen

    DC.

    Allen Chiropractic Orthopedics & The Gait Guys,

    Chicago, IL, United States

  • Christian Barton

    PT, Ph.D.

    Complete Sports Care,

    Melbourne, Australia

  • Jason Bonacci

    PT, Ph.D.

    School of Exercise & Nutrition Sciences

    Deakin University, Australia

  • Nicholas A. Campitelli

    DPM.

    Northeast Ohio Medical Associates

    Kent State University College of Podiatric Medicine, United States

  • Roy T.H. Cheung

    PT, Ph.D.

    Department of Rehabilitation Sciences,

    The Hong Kong Polytechnic University, Hong Kong

  • Mark Cucuzella

    MD

    West Virginia University School of Medicine

    USA

  • Irene S. Davis

    PT, Ph.D.

    Spaulding National Running Center, Departement of Physical Medicine and Rehabilitation

    Harvard Medical School, USA

  • Jay Dicharry

    MPT, SCS

    REP Biomechanics Lab

    Bend, OR, USA

  • Scott Douglas

    Senior contend editor

    Runner's World

    USA

  • Blaise Dubois

    PT

    Laval University & The Running Clinic

    Quebec City, Canada

  • Jean-Francois Esculier

    PT, M.Sc.

    Laval University & The Running Clinic

    Quebec City, Canada

  • Marlène Giandolini

    M.Sc.

    University of Saint-Étienne

    France

  • Allison Gruber

    Ph.D.

    Departement of Kinesiology, Indiana University in Bloomington

    USA

  • Bryan Heiderscheit

    PT, Ph.D.

    University of Wisconsin

    Madison, USA

  • Luiz Carlos Hespanhol Junior

    PT, M.Sc.

    VU University Medical Center

    Amsterdam, Netherland

  • Alex Hutchinson

    Ph.D.

    Senior Editor, Canadian Running Magazine

    Canada

  • D. Casey Kerrigan

    MD

    OESH shoes

    VA, USA

  • Peter Larson

    Ph.D.

    Performance Health Spine and Sport Therapy

    Concord, NH, USA

  • Greg Lehman

    PT, M.Sc.

    The Urban Athlete

    Toronto, Canada

  • Daniel E. Lieberman

    Ph.D.

    Departement of Human Evolutionary Biology, Harvard University

    USA

  • Everett Lohman, III

    D.Sc., PT

    School of Allied Health Professions, Loma Linda University

    USA

  • Alexandre Dias Lopes

    PT., Ph.D.

    Universidade Cidade de Sao Polo (UNICIDID), Sao Paulo Running Injury Group (SPRunIG)

    Sao Paulo, Brazil

  • Ray McClanahan

    DPM

    Northwest Foot and Ankle Clinic & Correct Toes

    Portland, OR, USA

  • Guillaume Y. Millet

    Ph.D.

    Human Performance Laboratory, Faculty of Kinesiology

    University of Calgary, Canada

  • Benno M. Nigg

    Dr.Sc.Nat.

    Human Performance Laboratory, faculty of Kinesiology

    University of Calgary, Canada

  • Timothy Noakes

    MD, DSc, Ph.D (hc)

    Departement of Human Biology

    University of Cape Town, South Africa

  • Craig Payne

    DPM

    Australia

  • Craig E. Richards

    B.Med.

    School of Biomecanical Sciences & Pharmacy

    University of New Castle, Australia

  • Michael Ryan

    Ph.D.

    Centre for Musculoskeletal Research

    Griffith University, Australia

  • Jacob Schelde

    MD

    Occupational Health Clinic

    Odense University Hospital, Denmark

  • Darren Stefanyshyn

    Ph.D., P.Eng.

    Human Performances Laboratory, Faculty of Kinesiology

    University of Calgary, Canada

  • Jack Taunton

    M.Sc., MD

    Division of Sports Medicine, Faculty of Medicine

    University of British Columbia, Canada

  • Daniel Theisen

    Ph.D

    Sports Medicine Research Laboratory

    Public Research Centre for Health of Luxembourg

  • Ross Tucker

    Ph.D

    Research Unit for Exercice Science and Sports Medicine

    University of Cape Town, South Africa

  • Ivo F. Waerlop

    DC

    Summit Chiropratic & Rehabilitation & The Gait Guys

    Dillon, CO, USA

  • Joe Warne

    B.Sc.

    School of Health and Human Performance

    Dublin City University, Ireland

  • John D. Willson

    PT, Ph.D

    East Carolina University

    USA

  • Richard W. Willy

    PT, Ph.D

    East Carolina University

    USA

Publications

  • EN

    Article

    Journal of Foot and Ankle Research, 2015, par Jean-Francois Esculier, Blaise Dubois, Clermont E. Dionne, Jean Leblond and Jean-Sébastien Roy. This standardised definition of minimalist shoes developed by an international panel of experts will improve future research on minimalist shoes and clinical recommendations. MI's adequate validity and reliability will allow distinguishing running shoes based on their degree of minimalism, and may help to decrease injuries related to footwear transition.

    Learn more