as a multifactorial measure of achilles tendon injury risk in triathletes

193 Pages·2014·17.77 MB·English

EVALUATING STIFFNESS OF THE LOWER LIMB ‘SPRINGS’
AS A MULTIFACTORIAL MEASURE OF ACHILLES TENDON
INJURY RISK IN TRIATHLETES

Anna Lorimer
BSc (Hons) Medicinal Chemistry Specialisation, PG Dip. (Sport & Exercise)

A thesis submitted to Auckland University of Technology in fulfilment of the requirements for the
degree of
Doctor of Philosophy (PhD)

August 2014

Faculty of Health and Environmental Sciences
TABLE OF CONTENTS
Evaluating Stiffness of the lower limb ‘springs’ as a multifactorial measure of achilles tendon
injury risk in triathletes ............................................................................................................... 1
Attestation of authorship .............................................................................................................. 7
Candidate contributions to co-authored papers ............................................................................ 8
Acknowledgements .................................................................................................................... 10
Ethical approval ......................................................................................................................... 11
Abstract ..................................................................................................................................... 12
Chapter 1 ................................................................................................................................... 15
Introduction, rationale for the studies based on critique of the literature, and structure of the thesis
(Preface) ............................................................................................................................. 15
Defining the issue ......................................................................................................... 15
Methodological approach to the issue ............................................................................ 15
Establishing the extent of the problem ............................................................................ 18
Achilles tendon properties ............................................................................................. 19
Mechanism of injury ..................................................................................................... 20
Risk factor analysis ...................................................................................................... 23
Establishing measures of lower limb stiffness. ................................................................. 25
How does lower limb stiffness change with different task constraints? .............................. 26
Can stiffness identify injury risk? ................................................................................... 29
Chapter 2 ................................................................................................................................... 31
Lower limb overuse injuries in New Zealand high performance triathletes ................................ 31
Overview ..................................................................................................................... 31
Introduction ................................................................................................................. 32
Methods....................................................................................................................... 33
Results......................................................................................................................... 34
Discussion ................................................................................................................... 36
Conclusions ................................................................................................................. 37
Chapter 3 ................................................................................................................................... 38
Achilles tendon injury risk factors associated with running: A Systematic review ...................... 38
Overview ..................................................................................................................... 38
Introduction ................................................................................................................. 39
Methods....................................................................................................................... 41
Results......................................................................................................................... 43
Discussion ................................................................................................................... 50
Conclusions ................................................................................................................. 54
Chapter 4 ................................................................................................................................... 55
Stiffness as a risk factor for Achilles tendon injury in triathletes and other running athletes:
Systematic review ................................................................................................................ 55
Overview ..................................................................................................................... 55
Introduction ................................................................................................................. 56
Methods....................................................................................................................... 58
Results......................................................................................................................... 61
Discussion ................................................................................................................... 69
Conclusions ................................................................................................................. 73
Chapter 5 ................................................................................................................................... 75
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Comparison of methods for quantifying stiffness and their reliability in triathletes ..................... 75
Overview ..................................................................................................................... 75
Introduction ................................................................................................................. 75
Methods....................................................................................................................... 79
Results......................................................................................................................... 82
Discussion ................................................................................................................... 89
Conclusions ................................................................................................................. 91
Chapter 6 ................................................................................................................................... 92
Lower limb stiffness is affected by running pace in triathletes .................................................. 92
Overview ..................................................................................................................... 92
Introduction ................................................................................................................. 93
Methods....................................................................................................................... 94
Results......................................................................................................................... 96
Discussion ................................................................................................................... 98
Conclusions ............................................................................................................... 102
Chapter 7 ................................................................................................................................. 103
Reliability and variability of lower limb stiffness with changes in running pace for triathletes .. 103
Overview ................................................................................................................... 103
Introduction ............................................................................................................... 104
Methods..................................................................................................................... 105
Results....................................................................................................................... 108
Discussion ................................................................................................................. 112
Conclusions ............................................................................................................... 115
Chapter 8 ................................................................................................................................. 115
Influence of prior cycling on lower limb stiffness in triathletes .............................................. 116
Overview ................................................................................................................... 116
Introduction ............................................................................................................... 117
Methods..................................................................................................................... 119
Results....................................................................................................................... 122
Discussion ................................................................................................................. 125
Conclusions ............................................................................................................... 128
Chapter 9 ................................................................................................................................. 129
Lower limb stiffness for the prediction of Achilles tendon injuries in triathletes: A prospective study
......................................................................................................................................... 129
Overview ................................................................................................................... 129
Introduction ............................................................................................................... 130
Methods..................................................................................................................... 131
Results....................................................................................................................... 134
Discussion ................................................................................................................. 141
Limitations ................................................................................................................ 144
Practical recommendations ......................................................................................... 144
Conclusions ............................................................................................................... 145
Chapter 10 ............................................................................................................................... 146
Discussion and conclusions ................................................................................................. 146
Limitations ................................................................................................................ 156
Future directions ........................................................................................................ 157
Conclusions ............................................................................................................... 158
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References................................................................................................................................ 160
Appendix 1 ............................................................................................................................... 185
AUT Ethics Committee approval – 3rd June 2011 .................................................................. 185
Appendix 2 ............................................................................................................................... 187
AUT Ethics Committee approval – 12th December 2011 ........................................................ 187
Appendix 3 ............................................................................................................................... 189
Table of study characteristics and quality scores – Chapter 4 ................................................. 189

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LIST OF FIGURES
Figure 1.1: Flow of thesis themes and chapters ................................................................................. 18
Figure 2.1: Injury frequencies for male and female triathletes in the Triathlon New Zealand High
Performance Program from 2007 to 2012 ............................................................... 35
Figure 3.1: Cycle of tendon homeostasis and degeneration ................................................................ 40
Figure 3.2: Flow of information through the different phases of the systematic review ......................... 42
Figure 3.3: Forest plot of effect size (ES) with 95% confidence interval for runners with Achilles tendon
injuries compared to uninjured .............................................................................. 49
Figure 4.1: Biomechanical stiffness models; a). basic vertical and leg stiffness (159), b). joint stiffness
(170) ................................................................................................................... 58
Figure 4.2. Flow of information through the different phases of the systematic review ......................... 60
Figure 5.1: Biomechanical stiffness models...................................................................................... 76
Figure 5.2: Lower body marker locations without and with tracking clusters ....................................... 80
Figure 6.1: Lower body marker locations without and with tracking clusters ....................................... 95
Figure 7.1: Lower body marker locations without and with tracking clusters ..................................... 106
Figure 7.2: a). average within-athlete lower body stiffness variability with increasing pace, b). between-
athlete lower body stiffness variability with increasing pace .................................. 111
Figure 7.3: Hip a). knee b). and ankle c). within-athlete coefficient of variation with increasing running
pace. ................................................................................................................. 112
Figure 8.1: Lower body marker locations without and with tracking clusters ..................................... 120
Figure 9.2: a). Comparison of stiffness measures between PriorUninjured and Uninjured groups ........ 137
Figure 9.2 cont.: b). Comparison of stiffness measures between PriorAchilles and Uninjured groups .. 138
Figure 9.2 cont.: c). Comparison of stiffness measures between FirstAchilles and Uninjured groups ... 139
Figure 9.2: d). Knee/ankle stiffness ratio, comparison of each group with the Uninjured group ........... 140
Figure 9.3: Between subject variability for various stiffness measures .............................................. 141
Figure 10.1. Van Mechlen’s et al. (23) ‘sequence for injury prevention' ............................................ 147
Figure 10.2: Within-athlete knee a). and ankle b). stiffness variability between the Uninjured and the
AllAchilles groups ............................................................................................. 152
Figure 10.3: Effect of increasing pace on the knee/ankle stiffness ratio ............................................. 155
Figure 10.4: Effect of prior cycling on the knee/ankle stiffness ratio during running .......................... 155

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LIST OF TABLES
Table 2.1: Triathlete numbers, and athletes injured, in the Triathlon New Zealand High Performance
program from 2007 to 2012 .................................................................................. 35
Table 3.1: Summary of findings for differences between uninjured runners and runners with Achilles
tendon injuries ..................................................................................................... 44
Table 3.1 (cont.): Summary of findings for differences between uninjured runners and runners with
Achilles tendon injuries ........................................................................................ 45
Table 3.1 (cont.): Summary of findings for differences between uninjured runners and runners with
Achilles tendon injuries ........................................................................................ 46
Table 3.1 (cont.): Summary of findings for differences between uninjured runners and runners with
Achilles tendon injuries ........................................................................................ 47
Table 3.1 (cont.): Summary of findings for differences between uninjured runners and runners with
Achilles tendon injuries ........................................................................................ 48
Table 4.1: Effect of the five clear Achilles tendon risk factors on lower body stiffness measures .......... 62
Table 4.2: Effect of Achilles tendon injury risk factors on lower body stiffness measures .................... 64
Table 4.2 (cont.): Effect of Achilles tendon injury risk factors on lower body stiffness measures .......... 65
Table 4.2 (cont.): Effect of Achilles tendon injury risk factors on lower body stiffness measures .......... 66
Table 4.2 (cont.): Effect of Achilles tendon injury risk factors on lower body stiffness measures .......... 67
Table 4.2 (cont.): Effect of Achilles tendon injury risk factors on lower body stiffness measures .......... 68
Table 5.1: Biomechanical stiffness model calculations, variables and equipment ................................. 77
Table 5.2: Average stiffness for running and hopping tasks in triathletes ............................................ 83
Table 5.3: Summary of reliability results for various biomechanical stiffness models with comparison
between the different models and stiffness types for running and hopping tasks in
triathletes ............................................................................................................ 85
Table 5.3 cont.: Summary of reliability results for various biomechanical stiffness models with
comparison between the different models and stiffness types for running and hopping
tasks in triathletes ................................................................................................. 86
Table 5.3 cont.: Summary of reliability results for various biomechanical stiffness models with
comparison between the different models and stiffness types for running and hopping
tasks in triathletes ................................................................................................. 87
Table 5.3 cont.: Summary of reliability results for various biomechanical stiffness models with
comparison between the different models and stiffness types for running and hopping
tasks in triathletes ................................................................................................. 88
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Table 6.1: Biomechanical stiffness model calculations, variables and equipment ................................. 94
Table 6.2: Means and standard deviations for lower body stiffness measures with increasing running pace
........................................................................................................................... 97
Table 6.3: Magnitude of changes in stiffness for treadmill running with increasing pace in triathletes,
effect size with 90% confidence intervals ............................................................... 98
Table 7.1: Biomechanical stiffness model calculations, variables and equipment ............................... 107
Table 7.2: Mean (±SD) lower body stiffness with increasing running pace ....................................... 109
Table 7.3: Test-retest reliability for twelve triathletes with changing pace ......................................... 110
Table 8.1: Biomechanical stiffness model calculations, variables and equipment ............................... 121
Table 8.2: Average stiffness for isolated run and selected times during a transition run in triathletes ... 122
Table 8.3: Magnitude of change in lower body stiffness measures during a transition run compared to
isolated running in triathletes .............................................................................. 123
Table 9.1: Biomechanical stiffness model calculations, variables and equipment ............................... 133
Table 9.2: Least squares mean stiffness (95% confidence interval) measures for the different injury
groups at the four running paces .......................................................................... 135

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ATTESTATION OF AUTHORSHIP

I hereby declare that this submission is my own work and that, to the best of my knowledge and
belief, it contains no material previously published or written by another person nor material
which to a substantial extent has been accepted for the award of any other degree or diploma of
a university or other institution of higher learning, except where due acknowledgement is made
in the acknowledgements.

Chapters 2 to 8 of this thesis represent separate papers that are either published or are to be
submitted to peer-reviewed journals for consideration for publication. My contribution and the
contribution by the various co-authors to each of these papers are outlined in the “candidate
contributions to co-authored papers” table. All co-authors have approved the inclusion of the
joint work in this PhD thesis.

Anna Lorimer

August 2014

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CANDIDATE CONTRIBUTIONS TO CO-AUTHORED PAPERS

Chapter 2 Lorimer 80%,
Lorimer, A., Hume, P.A., Pearson, S. Retrospective injury NZ elite Hume 10%,
triathletes. To be submitted to New Zealand Journal of Sports Medicine. Pearson 10%
Chapter 3
Lorimer 90%,
Lorimer, A., Hume, P.A. Achilles tendon injury risk factors associated with
Hume 10%,
running. Sports Medicine, 2014, 44(10) 1459-72.
Chapter 4
Lorimer 90%,
Lorimer, A., Hume, P.A. Stiffness as a risk factor for Achilles tendon injury
in triathletes and other running athletes: Systematic review. Under review Hume 10%,
by Sports Medicine.
Chapter 5
Lorimer 80%,
Lorimer, A., Keogh, J.W., Hume, P., Comparison of methods for
Keogh 10%,
quantifying stiffness and their reliability in triathletes. Submitted to
Hume 10%
International Biomechanics (in review).

Chapter 6
Lorimer 80%,
Lorimer, A., Hume, P., Keogh, J. Lower limb stiffness is affected by
Hume 10%,
running pace in triathletes. To be submitted to Journal of Science and
Keogh 5%,
Medicine in Sport.

Chapter 7 Lorimer 85%,
Lorimer, A., Hume, P., Keogh, J. Reliability and variability of lower limb Hume 10%,
stiffness with changes in running pace for triathletes. To be submitted to
Keogh 5%,’
Sports Biomechanics.

Chapter 8
Lorimer 80%,
Lorimer, A., Hume, P., Pearson, S. Influence of prior cycling on lower limb
Hume 10%,
stiffness in triathletes. To be submitted to Sports Biomechanics.
Pearson 5%

8
Chapter 9
Lorimer 90%,
Lorimer, A., Hume, P. Lower limb stiffness for the prediction of Achilles
tendon injuries in triathletes: A prospective study. To be submitted to Hume 10%,
British Journal of Sports Medicine.

Anna Lorimer Professor Patria Hume Dr Justin Keogh

Dr Simon Pearson

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