Mechanics and Energetics of Footfall Patterns in Running

371 Pages·2014·2.37 MB·English

by  Allison H. Gruber

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Open Access Dissertations
9-2012
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Allison H. Gruber
University of Massachusetts Amherst
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Gruber, Allison H., "Mechanics and Energetics of Footfall Patterns in Running" (2012). Open Access
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MECHANICS AND ENERGETICS OF FOOTFALL PATTERNS IN RUNNING

A Dissertation Presented

by

ALLISON H. GRUBER

Submitted to the Graduate School of the
University of Massachusetts Amherst in Partial fulfillment
of the requirements for the degree of

DOCTOR OF PHILOSOPHY

September 2012

Department of Kinesiology
© Copyright by Allison H. Gruber 2012
All Rights Reserved
MECHANICS AND ENERGETICS OF FOOTFALL PATTERNS IN RUNNING

A Dissertation Presented

by

ALLISON H. GRUBER

Approved as to style and content by:

_________________________________________________
Joseph Hamill, Chair

_________________________________________________
Brian Umberger, Member

_________________________________________________
Richard E.A. van Emmerik, Member

_________________________________________________
Ian Grosse, Member

__________________________________________
Patty S. Freedson, Department Head
Department of Kinesiology
DEDICATION

To Mom and Kevin
ACKNOWLEDGEMENTS

Thank you to my committee for providing your expertise, your support, and
guidance through this process. Many people have helped and supported me through this
journey. I would like to specifically thank:
…Joe Hamill for his endless patience, giving me this invaluable experience and
opportunity, and for the many doors he has opened for me. …Carl Jewell, Sam del Pilar
II for their hard work and assistance. I couldn’t have done it without their help. …Brian
Umberger for taking me under his wing and going above and beyond mentoring and
tutoring me while learning the modeling process and much more. …Barry Braun, Rich
Viskochil for your endless assistance and brain storming. Richard van Emmerik for
exposing me to a “dynamical” way of thinking. …Paul Devita and Tibor Hortobagyi for
teaching me much more than I realized after leaving East Carolina. …Graham Caldwell
for being my first academic advisor and making sure I stayed on the right path. …Kirsten
Granados for help with pilot data collection. …the participants: I know the protocol
wasn’t fun or easy but I appreciate your help (especially those who I made be a subject
twice). …Brian Moscicki, Gixxer, Stryder, Kitty & Pete for sticking with me under less
than ideal circumstances and for your unconditional love and support. …and all the
people who have helped get me through this experience: Joe Seay, Patrick Rider, Ross
Miller, Lex Gidley, Tim Derrick, Steve Malin, Elizabeth Russell, Mike Busa, Jen Baird,
and others in the KIN family who have given me their support, and the Moscicki Family.
…and a special thanks to Florrie Blackbird. I wouldn’t be here today if you didn’t give
me the opportunity to work for you. Thank you for everything you’ve done for me.
v
ABSTRACT
.MECHANICS AND ENERGETICS OF FOOTFALL PATTERNS IN RUNNING
SEPTEMBER 2012
ALLISON H. GRUBER
B.S., EXERCISE SCIENCE, UNIVERSITY OF MASSACHUSETTS AMHERST
M.A., EXERCISE & SPORT SCIENCE, EAST CAROLINA UNIVERSITY
P.h.D., KINESIOLOGY, UNIVERSITY OF MASSACHUSETTS AMHERST

Directed by: Professor Joseph Hamill

The forefoot (FF) running pattern has been recently advocated to improve running
economy and prevent overuse injuries compared to the rearfoot (RF) pattern. However,
these claims have not been supported by empirical evidence. The purpose of this
dissertation was to investigate the potential advantages of RF and FF patterns to improve
running economy and reduce injury risk in 20 natural RF and 20 natural FF runners.
The first study found that the RF group was more economical when performing
the RF pattern at a slow, medium, and fast speed vs. FF running. Only running at the fast
speed resulted in a difference in economy between footfall patterns in the FF group in
which RF running was more economical. Therefore, there is no advantage of FF running
for improving running economy.
The results of the second study indicated that there was a weak to moderate
relationship between Achilles tendon (AT) moment arm length and running with either
RF or FF patterns. AT force was greater during FF running, which may increase the risk
of developing tendon injury.
The third study used a modeling approach to find that FF running resulted in
greater elastic energy recoil in the gastrocnemius (GA) and the soleus (SO). However,
greater mechanical work overall with FF running resulted in no difference in metabolic
cost of the GA between footfall patterns but greater metabolic cost of the SO compared to
RF running.
The fourth study found that shock attenuation was greater during RF running
compared to FF running. Greater shock attenuation during RF running was a result of an
increased load imposed on the system. Decomposing the vertical ground reaction force
in the frequency domain revealed that RF running may have a greater reliance on passive
shock attenuation mechanism whereas the FF pattern may have a greater reliance on
active shock attenuation mechanisms.
These results suggest that previous speculation that the FF running pattern is more
economical was not substantiated. It is likely that each footfall pattern exposes a runner
to different types of injuries, rather than one footfall pattern being more injurious than
another.
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TABLE OF CONTENTS

Page

ACKNOWLEDGEMENTS v

ABSTRACT vi

LIST OF TABLES xiii

LIST OF FIGURES xv

LIST OF EQUATIONS xviii

CHAPTER

1. INTRODUCTION 1

General Introduction 1

Relationship Between Running Mechanics and Economy 2
Achilles Tendon Moment Arm and Running Economy 3
Muscle Function and Elastic Energy Utilization in Running 5
Impact Parameters in Running 7

Problem Statement 10
Purpose 11
Significance 12
Hypotheses 13

Study 1 13
Study 2 14
Study 3 16
Study 4 17

Assumptions 18
Operational Definitions 18
Summary 18
References 20

2. REVIEW OF LITERATURE 28

General Introduction 28
Footfall Patterns Used in Running 28

vii
Characteristics of the Rearfoot Running Pattern 30
Characteristics of the Forefoot Running Pattern 32

Variations in Running Economy 35
Achilles Tendon Moment Arm 39
Muscle Function and Elastic Energy Utilization in Running 42

The use of Muskuloskeletal Models for Running Investigations 45

Impact Force, Impact Shock and Attenuation 53

Passive Mechanisms of Shock Attenuation 58
Active Mechanisms of Shock Attenuation 59
Is Forefoot Running Protective Against Running Injuries? 62

Summary 64
References 65

3. METHODOLOGY 82

General Introduction 82
Study 1: Is There a Difference in Running Economy Between
Rearfoot and Forefoot Running Patterns? 84

Introduction 84
Participant Selection 84
Experimental Set-up 86
Protocol 88
Data Reduction 89
Statistical Analysis 91

Study 2: Achilles Tendon Forces and Moment Arm Length
in Rearfoot and Forefoot Running 92

Introduction 92
Participant Selection 92
Experimental Set-up 93
Protocol 96
Data Reduction 97
Statistical Analysis 101

Study 3: Muscle mechanics and energy expenditure of the
triceps surae during rearfoot and forefoot running 102

Introduction 102
Participant Selection 102
viii
Musculoskeletal Model 103
Data Analysis 106
Statistical Analysis 107

Study 4: Impact Characteristics and Shock Attenuation Between
Footfall Patterns in Running 108

Introduction 108
Participant Selection 108
Experimental Set-up 108
Protocol 110
Data Reduction 110
Statistical Analysis 113

References 115

4. IS THERE A DIFFERENCE IN RUNNING ECONOMY BETWEEN
REARFOOT AND FOREFOOT RUNNING PATTERNS? 119

Abstract 119
Introduction 120
Methodology 123

Participant Selection 123
Experimental Set-up 124
Protocol 125
Data Reduction 126
Statistical Analysis 128

Results 129

Kinematics 129
Stride Characteristics 130
Running Economy Variables 131

Discussion 137
Conclusions 143
References 144

5. ACHILLES TENDON FORCES AND MOMENT ARM
LENGTH IN REARFOOT AND FOREFOOT RUNNING 149

Abstract 149
Introduction 150
Methodology 154

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