The effect of alterations in effective seat tube angle on Cycling performance, Economy and muscle

103 Pages·2017·2.51 MB·English

The effect of alterations in effective seat tube angle on cycling
performance, economy and muscle recruitment.
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A dissertation prepared by Teo Choon Chye (CHYTEO001) in partial fulfilment of

the requirements for the Master of Scifence degree in Medicine (by dissertation,
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MM095) from the University of Cape Town

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i13 October 2017
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The copyright of this thesis vests in the author. No
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quotation from it or information derived from it is to be

published without full acknowledgeement of the source.
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The thesis is to be used for private study or non-
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commercial research purposes only.

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Published by the Universit y of Cape Town (UCT) in terms
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of the non-exclusive license granted to UCT by the author.
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Declaration
I, Teo Choon Chye, hereby declare that the work on which this dissertation is based on
my original work (except where acknowledgements indicate otherwise) and that neither
the whole work nor any part of it has been, is being, or is to be submitted for another
degree in this or any other university.
No part of this dissertation may be reproduced, stored in a retrieval system, or transmitted
in any form or means without prior permission in writing from the author or the
University of Cape Town.
Signed by Candidate
Signature Removed
(Signature)
13 October 2017
(Date)
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Acknowledgements

I would like to start by acknowledge and thanking my supervisor, Dr Jeroen Swart for the
opportunity to participate in this research project and for his guidance and assistance
throughout.
I cannot continue without thanking and acknowledge my lab-mates. Both my lab-mates
that work directly in the same lab as me have been valuable resources. Wendy Holliday –
thank you for all of your support, advice, suggestions and data collection. Nikhil – thanks
for all the technical supports for 3D vicon, surface EMG and MATLAB
I definitely could not have done this project without all the cyclists that so willingly gave
their time to participate in this study. The willingness of cyclists to come into the lab for
two hours before they started their work days, and some extending their days to 930pm
after a long day of work. I am ever so grateful and humbled by the time they gave so
willingly to participation in this study.
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Table of Contents
Declaration 2
Acknowledgements 3
List of Tables 7
List of Figures 9
List of abbreviations 10
Abstract 11
Chapter 1 13
1.1. INTRODUCTION 13
1.2. STATEMENT OF THE PROBLEM 15
1.3. AIMS 15
1.4. SIGNIFICANCE OF THE STUDY 16
1.5. ASSUMPTIONS 16
1.6. LIMITATIONS 16
Chapter 2 17
2.1. REVIEW OF THE LITERATURE 17
2.2. CYCLING MOTION AND PERFORMANCE 17
2.3. CYCLING KINEMATICS 18
2.3.1. SEAT HEIGHT AND JOINT KINEMATICS 19
2.3.2. WORKLOAD AND JOINT KINEMATICS 20
2.4. MUSCLE ACTIVITY DURING CYCLING 21
2.4.1. SEAT TUBE ANGLE AND MUSCLE ACTIVITY 23
2.4.2. EXHAUSTIVE CYCLING AND MUSCLE ACTIVITY 24
2.4.3. BODY POSITIONING AND MUSCLE ACTIVITY 25
2.4.4. TRUNK ORIENTATIONS AND MUSCLE ACTIVITY 25
2.5. METABOLIC ECONOMY DURING CYCLING 26
2.5.1. SEAT TUBE ANGLE AND PHYSIOLOGICAL PARAMETERS 27
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2.5.2. SEAT TUBE ANGLE AND POWER OUTPUT 28
2.6. INSTRUMENTS AND METHODOLOGY 28
2.7. CYCLE ERGOMETER 29
2.7.1. DURATION AND INTENSITY 30
2.8. SUMMARY OF CHAPTER 31
Chapter 3 32
3.1. METHODOLOGY 32
3.1.1. PARTICIPANT SELECTION 32
3.1.2. EXPERIENTAL DESIGN 32
3.1.2.1. PRELIMINARY VISIT 33
3.2 EQUPIMENT AND TESTING PROTOCOLS 35
3.2.1. CYCLE ERGOMETER 35
3.2.2. BODY COMPOSITION 35
3.2.3. LAMBERTS AND LAMBERT SUBMAXIMAL TEST (LSCT) 35
3.2.4. PEAK POWER OUTPUT (PPO) 36
3.2.5. NORMALIZATION 36
3.2.6. CONSTANT WORLOAD 37
3.2.7. THREE DIMENTIONAL (3D) KINEMATICS 37
3.2.8. ELECTROMYOGRAPHY (EMG) 37
3.3. STATISTICAL ANALYSES 38
Chapter 4 39
4.1. RESULTS 39
4.1.1. SUBJECT CHARACTERISTICS 39
4.1.2. INCREMENTAL CYCLE TEST 40
4.2. SUBMAXIMAL STEADY STATE CYCLING PHYSIOLOGICAL VARIABLES 40
4.3. JOINT KINEMATICS 44
4.3.1. MAGNITUDE-BASED INFERENCES FOR JOINT KINEMATICS 47
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4.4. MUSCLE ACTIVATION 49
4.4.1. MAGNITUDE-BASED INFERENCES FOR EMG 51
Chapter 5 53
5.1 DISCUSSION 53
5.2 JOINT KINEMATICS 53
5.3 METABOLIC COSTS DURING STEADY STATE CYCLING 54
5.4 MUSCLE ACTIVATIONS 56
5.5 CONCLUSION 57
References 59
Appendixes 71
Table of contents 71
1. Advertisement for recruitment 72
2. Physical Activity Readiness Questionnaire 73
3. Informed consent form 74
4. De Pauw’s Guidelines to classify subject groups in sport-science research 80
5. Physical Activity and training Questionnaire 81
6. Bicycle configuration measurements 89
7. VICON markers 92
8. EMG Placement 93
9. Body chart for Numerical Pain Scale 98
10. Borg Scale for Rate of Perceived Exertion 99
11. Data collection sheet 100

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List of Tables

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Table 2.1: Summary of studies using a cycle ergometer for manipulating of 29
the STAs during cycle trials.

Table 4.1: Summary of participant training history and status.
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Table 4.2: Participant characteristics and physiological attributes of the ten 40
trained cyclists measured during incremental cycle test.

Table 4.3: Physiological attributes of the ten cyclists during submaximal
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cycling test. P-values for Time x Trial interaction.

Table 4.4: Value differences for physiological attributes between saddle
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displacements.

Table 4.5: Mean changes in physiological attributes between saddle
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displacements.

Table 4.6: Shoulder, hip, knee, ankle, and elbow joint kinematics for fifteen
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pedals cycle during submaximal steady state cycling. P-values for
Time x Trial interaction.

Table 4.7: Shoulder, hip, knee, ankle, and elbow joint kinematics across the
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three different time segmentnts. P-values for Time x Trial

interaction.
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Table 4.8: Value differences for kinematics measurement between saddle
displacements.

Table 4.9: Mean changes in kinematics variables between saddle
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displacements.

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Table 4.10: Normalized EMG values for fifteen pedal cycles during 49

submaximal steady state cycling. P-values for Time x Trial

interaction.

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Table 4.11: Value differences for EMG measurement between saddle

displacements.

Table 4.12: Mean changes in EMG variables between saddle displacements 52

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List of Figures

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Figure 1.1: Seat tube angle 14

Figure 1.2: Effective seat tube angle
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Figure 2.1: Common joint angles measurement during cycling
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Figure 3.1: Visualization of data capture during an hour long steady

state cycling.

Figure 4.1: Mean physiological attributes between saddle 41
displacements for the three time points recorded in each
trial.

Figure 4.2: Mean joint kinematics between saddle displacements for
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the three time points recorded in each trial.

.Figure 4.3: Normalized EMG amplitude for Biceps femoris (BF), 50
Gluteus Maximus (GM), Tibialis Anterior (TA), Vastus
Lateralis (VL), Vastus Medialis (VM), Rectus Femoris
(RF) and Medial Gastrocnemius (MG) at 70% of PPO.

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