The effect of three different cooling gels on acute non-specific low back pain

130 Pages·2015·2.03 MB·English

The effect of three different cooling gels on
acute non-specific low back pain
By
Cleo Kirsty Prince

A dissertation submitted to the Faculty of Health at the Durban University of
Technology in partial compliance with the requirements for the Master‟s Degree in
Technology: Chiropractic

I, Cleo Kirsty Prince do declare that this dissertation is a representation of my own
work in both conception and execution.

Signed: __________________ Date: __________________
C. K. Prince

Approved for final examination

Signed: ___________________ Date: _________________
Dr. L.M. O‟ Connor
MTech: Chiropractic
Supervisor

Signed: ___________________ Date: _________________
Prof. D. Gerber
BVSc, Dr.med.vet
Co-Supervisor
DEDICATION

This dissertation is dedicated to:

My Lord and Saviour Jesus Christ
Who makes all things possible in His time

To my Mum and Dad, words cannot express the eternal gratitude I will always have
for the two of you for helping me pursue my dreams. The countless sacrifices and
hard work that you have put towards my education is the greatest gift you could have
ever given to me. Thank you for being mentors, confidants and role models.

To my brother, Cuan, I cannot thank you enough for your support and
encouragement throughout my years of studying.

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ACKNOWLEDGEMENTS

Dr. Laura O‟Connor, my supervisor, thank you for all your support, guidance and
assistance throughout this research.

Prof David Gerber, my co-supervisor, thank you for offering up your time to assist me
in my research.

Healthtech Laboratories, thank you for your sponsorship and enabling me to carry
out this research.

The lecturers at the Chiropractic Department, thank you for the support and
dedication you all show towards educating us. I will forever be grateful for all your
assistance throughout my studies.

Pat, Linda, Kershnee and Wendy, a big thank you for all that you have done for me
during my studies.

Tonya Esterhuizen, thank you for your assistance with my statistical analysis.

Lyle Fredericks, thank you for your support, understanding and care throughout my
studies. I appreciate everything that you have done for me and continue to do for me
daily.

To my class mates, it has been a pleasure getting to know you and I wish you all the
best for your future endeavours.

A sincere thank you to the participants who dedicated their time to take part in this
research study, it would not have been possible without your help.
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ABSTRACT

Background

Cryotherapy is often the first option in treating acute conditions and can be applied in
various forms including ice packs and cooling gels. Cooling gels are easy to use and
readily available making them popular with consumers. They can also contain
additional ingredients which can assist with inflammation, making them ideal for
musculoskeletal disorders. A cooling gel containing menthol and anti-inflammatory
herbs is available in pharmacies nationwide in South Africa, but has not been
clinically investigated. This gel is often used in the treatment of acute injuries such as
low back pain but its effectiveness in treating this condition has not yet been verified.
Objectives

To determine the effectiveness of a menthol cooling gel combined with anti-
inflammatory herbs compared to a menthol gel and a placebo gel in the treatment of
acute non-specific low back pain.

Method

A double-blinded placebo controlled clinical trial (n = 60) was conducted. Each
participant was randomly allocated into one of three treatment groups consisting of a
minimum of 20 participants between the ages of 18 and 40 who met the study
criteria. Informed consent was obtained from the participants prior to their
participation in the study. At the initial consultation baseline measurements (pain
rating, disability and pressure pain threshold) were taken and the respective
treatments (menthol with anti-inflammatory herb, menthol or placebo gel) were
administered. Participants were instructed on how to apply the gel at home and were
requested to apply it three times a day for one week. Statistical analysis was
performed using repeated measures ANOVA for inter- and intra-group analysis with
one way ANOVA and chi square tests being used to compare baseline values. A p-
value < 0.05 was considered to be statistically significant. The study received ethical
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clearance from the Durban University of Technology Institutional Research Ethics
Committee (REC 81/13).

Results

No significant differences were observed between the groups at baseline
assessment, indicating that the groups were comparable. Participants were
instructed on how to apply the gel at home and were requested to apply it three
times a day for one week. Follow up appointments for data collection was scheduled
at days three or four and six. No statistically significant differences were observed
between the three groups over time for pain (p = 0.95), disability (p = 0.903) or
pressure-pain threshold (p = 0.824), with all groups showing improvement. All three
groups showed clinically significant changes in pain from moderate to mild over the
duration of the study but no clinically significant changes were noted in terms of
pressure-pain threshold and disability.

Conclusion

The results indicate that irrespective of whether or not the gel contains active
ingredients there was an improvement in acute low back pain. Further research
needs to be conducted to determine if tissue depth and the concentration of the
active ingredients such as menthol are factors affecting the efficacy of this gel.
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TABLE OF CONTENTS

DEDICATION .......................................................................................................... ii
ACKNOWLEDGEMENTS ....................................................................................... iii
ABSTRACT ............................................................................................................ iv
TABLE OF CONTENTS .......................................................................................... vi
LIST OF FIGURES ................................................................................................. xi
LIST OF TABLES .................................................................................................. xii
LIST OF APPENDIXES ........................................................................................ xiii
Chapter 1 : INTRODUCTION ..................................................................................... 1
1.1 The problem and its setting ........................................................................... 1
1.2 The research question, study aims and objectives ........................................ 3
1.2.1 The research question ............................................................................ 3
1.2.2 The study aims ....................................................................................... 3
1.2.3 The study objectives………………………………………………………….3
1.3 The flow of the dissertation ........................................................................... 5
Chapter 2 : LITERATURE REVIEW ........................................................................... 6
2.1 Introduction ....................................................................................................... 6
2.2. A brief overview of the anatomical structures of the low back ......................... 6
2.2.1 The bony structures of the low back ........................................................... 6
2.2.2 Soft tissue structures in the low back ......................................................... 8
2.2.3 Vasculature of the low back ...................................................................... 9
2.2.4 Innervation of low back ............................................................................ 10
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2.3 Low back pain ................................................................................................. 10
2.3.1 Epidemiology of low back pain ................................................................. 10
2.3.2 Classification of low back pain ................................................................. 11
2.3.3 Pathophysiology of mechanical low back pain ......................................... 11
2.3.4 Diagnoses of low back pain...................................................................... 12
2.3.5 Management of acute low back pain ........................................................ 13
2.4 Cryotherapy .................................................................................................... 15
2.4.1 The mechanism of action ......................................................................... 15
2.4.1.1 Traditional methods of cryotherapy and their mechanism of action ... 16
2.4.1.2 Cryotherapy methods that utilise the excitation of the transient
receptor potential ion channels and their mechanism of action ..................... 19
2.4.1.3 Cryotherapy methods that utilise continual tactile stimulation and their
mechanism of action ...................................................................................... 21
2.4.2 Menthol cooling gels with additional additives .......................................... 21
2.4.3 Factors affecting the successful application of menthol cooling gels ....... 26
2.4.4 Methods of assessing the effect of cryotherapy modalities ...................... 27
2.4.4.1 Measures of pain ............................................................................... 27
2.4.4.2 Measures of disability ........................................................................ 28
2.4.4.3 Measures of pressure-pain threshold ................................................ 29
2.4.4.4 Measures of blood flow ...................................................................... 29
2.5 The placebo effect .......................................................................................... 29
2.5.1 Mechanism of action ................................................................................ 30
Chapter 3 : MATERIAL AND METHODS ....................Error! Bookmark not defined.
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3.1 Study design ................................................................................................... 32
3.2 Participant recruitment .................................................................................... 32
3.3 Sampling ......................................................................................................... 32
3.3.1 Sample size .............................................................................................. 32
3.3.2 Sample strategy and allocation ................................................................ 33
3.3.3 Participant characteristics ........................................................................ 33
3.4 Measurement tools ......................................................................................... 35
3.4.1 Objective measurements.......................................................................... 36
3.4.1.1 Pressure-pain threshold..................................................................... 36
3.4.2 Subjective measurements ........................................................................ 37
3.4.2.1 Pain rating ......................................................................................... 37
3.4.2.2 Disability from low back pain ............................................................. 37
3.5 Interventions ................................................................................................... 37
3.5.1 Gel application ......................................................................................... 38
3.5.2 Treatment duration ................................................................................... 38
3.6. Research procedure ...................................................................................... 39
3.7 Data analysis .................................................................................................. 40
3.8 Ethical considerations ..................................................................................... 40
Chapter 4 : RESULTS .............................................................................................. 42
4.1 Consort diagram ............................................................................................. 42
4.2 Participant characteristics ............................................................................... 43
4.2.1 Gender ..................................................................................................... 43
4.2.2 Race ......................................................................................................... 43
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4.2.3 Age ........................................................................................................... 44
4.2.4 Height, weight and body mass index (BMI) .............................................. 44
4.2.5 Occupation ............................................................................................... 45
4.3 Pain rating ...................................................................................................... 45
4.4 Disability ......................................................................................................... 46
4.5 Pressure-pain threshold .................................................................................. 47
Chapter 5 : DISCUSSION ...........................................Error! Bookmark not defined.
5.1 Participant characteristics ............................................................................... 48
5.1.1 Gender, race and age .............................................................................. 48
5.1.2 Height, weight and body mass index (BMI) .............................................. 49
5.1.3 Occupation ............................................................................................... 50
5.2 Discussion of the results ................................................................................. 50
5.2.1 Pain rating ................................................................................................ 50
5.2.2 Disability ................................................................................................... 54
5.2.3 Pressure-pain threshold (PPT) ................................................................. 54
5.3 Review of the hypothesis ...................................Error! Bookmark not defined.
Chapter 6 : CONCLUSION AND RECOMMENDATIONS ........................................ 56
6.1 Conclusions .................................................................................................... 56
6.2 Recommendations .......................................................................................... 56
6.2.1 Recommendations for future research ..................................................... 56
6.2.2 Recommendations for clinical practice ..................................................... 57
6.3 Study limitations…………………………………………………………………… 54
REFERENCE LIST ............................................................................................... 59
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APPENDIXES ....................................................................................................... 84
x