Comparing Muscle Size and Strength in Rugby and Football Players

The assignment content is an information sheet and consent form for a study comparing the cross-sectional area and muscle strength in the upper leg muscles of rugby players and football players. The study aims to investigate whether there is a difference between the two groups. Participants will be asked to complete a series of tests, including ultrasound scans and girth measurements, and will receive their own results. The data collected will be held securely at the University of Bedfordshire and may be published in the future. Participants are free to withdraw from the study at any time without disadvantage or prejudice.

‘Muscle Quality: The analysis of muscle
quality in the Rectus Femoris of university
Rugby and Football players’
Dissertation SPEO01-3
Reinaldo Camuimba – 1115230
[e-mail]
Sport Science and Coaching
‘I declare that this is my own work and should this declaration be found to be untrue I
acknowledge that I may be guilty of committing an academic offence’
Laura Charalambous
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Purpose of study: To identifying the components of muscle quality and identify
which of the groups compared out of the University of Bedfordshire rugby and
footballers tested which one have a higher level of muscle quality.
Introduction: Superior muscle mass commonly develops higher muscle strength.
Whereas, higher muscle mass is perceived on whether it may develop a better muscle
Quality (Barbat-Artigas et. al. 2013). The use of ultrasound was seen as the
appropriate method to examine ordinary and pathological muscle tissue, as its images
produced are non-interference to the actual muscle and the images are simultaneous
(Pillen, 2011).
Methods: 10 participants from each sports were selected from a group of university
Rugby and Football players to participate in a peak force test of a seated leg extension
test, then using a Vivid Ultrasound to assess the Cross-Sectional area of the rectus-
femoris using t a water-based gel at a gentle stable pace in order to generate a good
clear image on the ultrasound. Thus the equation to identify muscle quality in
individuals would be to identify the cross-sectional area of the muscle and x it by the
force produced by the selected muscle.
Results: Results presented in this study show that there was a significant difference in
muscle quality production in rugby players and football players. (P>0.05.) P = 0.006
using an independent sample T-test; (t= 1.072), df 18. Results also identified that
there was a significant difference between the values of muscle quality calculation on
non-dominant leg of rugby and football players (P<0.05.) P = 0.000 using an
independent sample T-test; (t= -.029), df =18. The results also identified that there
was a significant difference in the values of peak force generated in non-dominant leg
between rugby and football players. (P<0.05.) P = 0.005 using an independent
sample T-test; (t= 0.125), df 18.
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lack of literacy and communal groups the revolts will remain isolated to these same
groups; Thus, the point emphasised by Tarrow is that only when the issue affects
many people across town, across countries, who posses great organisational skills,
that is when the issue will become one which is widely contested. Furthermore, the
role of movement networks are also identified as integral in the outcome of the social
movement as a whole1.
Its outlined by Beach and Penderson how theories are researched. Their methods will
help in relation to my question; as it will be ascertained which circumstances convey
when group activism is more effective than individual action. Beach and Penderson
explain the use of evidence and observation as well as sometimes having to use
inference to fill in the gaps about theories we may believe to be true in real life2. It is
expressed that finding empirical evidence to support claims is extremely imperative,
as making generalisations about cases rarely works when trying to understand the
mechanisms of why and how outcomes were reached3.
Bloom’s argument is in agreement with that of Andrews, and states that the CRM
played a major part in not only causing contention, but also raising awareness of the
racial problems in American society. Bloom stresses that although Political
Opportunity Theory (POT) highlights the importance of macro structural shifts in
making established authorities vulnerable to insurgent challenges; it is too generative
and thus somewhat insufficient as the only explanation of racial insurgency4.
Theorising opportunity for groups falsely suggests that conditions for mass contention
1 Tarrow, Sidney. Power in Movement: Social Movements and Contentious Politics . Second edition .
Camebridge : Cambridge University Press , 1998. pp . 49
2 Beach, D. and Pedersen, R.B. (2013) Process-tracing methods: Foundations and guidelines. United States:
University of Michigan Press.
3 Beach, D. and Pedersen, R.B. (2013) Process-tracing methods: Foundations and guidelines. United States:
University of Michigan Press.
4 Bloom, Joshua. "The Dynamics of Opportunity and Insurgent Practice: How Black Anti-colonialists
Compelled Truman to Advocate Civil Rights." American Sociological Review, 2015: 391-415.
iii

are either propitious or not which would further assume that in times of quiescence
insurgency is futile. Furthermore, political opportunity structures
Acknowledgements:
Firstly, I would like to thank family and friends that helped and supported me through
my University journey. I would also like to show gratitude to all the participants that
found spare time to contribute their effort in my study. I would also like to show my
upmost appreciation for the support that my dissertations tutor Laura Charalambous
provided me throughout my studies. Lastly I would like to thank a very special person
to me that supported me through my university journey through my good times and
hard times but Zainab has still been there to be my voice of reasoning and help me
continue my studies.
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Contents Preliminaries
Title Page i
Abstract ii
Acknowledgements iv
1. Chapter 1: Introduction
2. Chapter 2: Literature Review
3. Chapter 3: Method
4. Chapter 4: Results
5. Chapter 5: Discussion
6. Chapter 6: Conclusions
7. Chapter 7: References
8. Chapter 8: Appendix
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Introduction:
Superior muscle mass, may have optimistic relationship to higher muscle strength.
Conversely, higher muscle mass can be frequently linked to having a higher
proportion of muscle quality. (Barbat-Artigas et. al. 2013). Muscle quality in an
individual could be defined in three forms such as; muscle force created in the muscle
per unit of the muscle size, the relationship between the size of the muscle and the
amount of power the muscle could produce (Barbat-Artigas et. al. 2012). Muscle
Quality in the human body is assessed by the level of forced produced. Through the
development of athletes, coaches would design suitable training programs for athletes
in their sports so it would produce the form of muscle endurance and quality that
would build an athlete’s perseverance through performance and training programs
manufactured for them by the coach. Whilst an extensive quantity of consideration
has been paid to the relationship between muscle quality and muscle size through
athlete training there are very few research studies that consider the true meaning of
muscle quality in athletes, neither scientists nor athletic coaches have considered to
look at the difference in muscle size and muscle quality. Though muscle quality
analysis in humans has linked to a strong improvement in their performance. Studies
have shown that great muscle quality is force generated by the muscle divided by the
cross sectional area of the muscle (Barbat-Artigas et. al. 2013), but who’s to say that
athletes from other sports may not have great muscle quality from not having a great
cross sectional muscle area, and that the muscle may not produce a great amount of
force from the muscle? Within the structure of the human anatomy it is thought that
the greater quadriceps muscle mass may be, the stronger the muscle is. The human
muscle mass extremely associates itself to the purpose of the muscle (English et al,
2011). But not in every circumstance does this truly transpire. Customarily the actual
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muscle doesn’t actually have to be of a superior size to display an excessive quantity
of force. The theory behind this is due to quality of muscle in the individual. They
may have a sizeable smaller muscle but could also display a high amount of strength
compared to an individual with a larger muscle size.
The muscle Rectus Femoris is found in the quadriceps, the Rectus Femoris originates
at the hip - Anterior Inferior Iliac Spine, and inserts at the Quadriceps Tendon.
Connecting itself from the hip to the knee to the hip and assists with hip flexion and
extension of the knee on the extension or elevation of the knee. The Rectus Femoris
contracts alongside the whole quadriceps. Of the whole Quadriceps the main muscle
that helps on the contraction and tension of the muscle is the Rectus Femoris.
What this study aims to measure is measure the cross sectional area of the quadriceps
femoris and if the parts correlate with muscle force within the Quadriceps muscle
specifically on the Rectus Femoris muscle. Analysing the muscle through ultrasound
is an appropriate practice on picturing the standard and pathological muscle tissue.
Thus the aim of this study is to analyse what are the true definition of muscle quality
and what type of sports tends to produce a greater muscle quality in athletes. By
analysing athletes both from rugby and football, we would then distinguish which
sporting method produced a greater muscle quality in athletes.
Rationale: Initially the assumption of a larger muscle size would mean a better form
of muscle quality. This assumption was determined by assuming that if an individual
attains a larger muscle size automatically they would generate a great amount of force
from that specific muscle. this study will attempts to identify the components of
muscle quality and also attempt to identify from the two sports being compared
which one of them helps athletes have a greater muscle quality in the rectus femoris.
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Hypothesis: It is hypothesised that the university rugby players from this study will
show a significant difference in muscle quality in the Rectus Femoris in comparison
to the muscle quality in the university footballers.
Literature review:
What is muscle quality: There are three major factors that define muscle quality; this
includes muscle force generated per unit of muscle quantity, and the muscle capacity
of muscle size in relation to how much power the muscle produces on its own. Thus,
calculating the quality in muscle could have the involvement of: muscle size, muscle
force and muscle power produced (Barbat-Artigas et. al. 2012).
Muscle mass: The magnitude of muscle that makes the muscle or muscle group.
Muscle mass may differ on the form and size (Kent, 1998). There are various forms
of methods on measuring muscle mass in humans. The expense and accessibility of
the methods can regulate the most reliable method appropriate to when using for
Scientific Research or clinical practice (Barbat-Artigas et. al. 2012). Heymsfield et.
Al. 2010, listed various different methods on how to test muscle mass such as for
example ultrasound figure imaging. There are three image methods on how to
evaluate muscle mass or lean muscle mass, these methods are CT Scanning, MRI and
Dual-energy X-ray Absorbtion (DXA). From recent studies it indicates that CT
scanning and MRI are the highest standard in the analysis of muscle mass, while DXA
has an ease of access for both sports specific research and clinical practice. The use of
muscle Ultrasound scanning is another technique used to analyse muscle mass in
humans. With this method it provides evidence of penation angle in the muscle
(Barbat-Artigas et. al. 2012). Bio-impendence testing views the quantity of fat and
lean muscle mass in the body. But however, the accessibility and cost of this method
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is if ease to access the method and may be a cheap and handy practice DXA.
Additionally Janssen et al. (2002), proposed an equation for valuing skeletal muscle
mass using Bioelectric Impendence Analysis (BIA). By using anthropometric
procedures it could be one of the most simple approaches to measuring skeletal? body
muscle mass. But through the use of this method, could occur various faults and it has
vulnerabilities. A final way of examining muscle mass could be the use of urinary
creatinine excretion. Nevertheless, as irregularity of accuracy of the results still
continue to be unclear, this method of analysis isn’t recommended as conclusive
assessment of muscle mass.
Muscle strength
Muscle strength is defined as the force or the tension that a muscle or more
profoundly a muscle group may generate in contradiction of a resistance in a single
all-out exertion (Kent, 1998). Strength in the muscle can be measured through several
different muscle groups, these include, hand grip and knee flexors and extensors.
They tend to be the most popular muscle groups reviewed (Barbat-Artigas et. al.
2012). Assessing lower limbs in the body are more important to the limbs in the upper
body for movement and bodily tasks. Nevertheless, hand grip power is used
commonly used due to the ease accessibility and has upbeat reports on being a worthy
sign of general muscle strength (Rantanen et. al. 1994). There are two different
methods on how to assess muscle strength in the body; a one repetition maximum and
a dynamometry test. Using a one repetition maximum test requires an individual to
execute an all-out bout of exertion, to lift a weight on specified exercises. Using this
method can regulate individuals’ maximum strength on specific muscle groups.
Dynamometers testing require a device that permits isometric and isokinetic
assessments on muscle strength for example, concentric or eccentric force at altered
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speeds (Hortobagyi, T et al. 1995). However, as individuals age - eccentric muscle
strength can have less of an affect compared to concentric muscle strength
(Hortobagyi, T et al. 1995) and (Porter, M et al. 1995). Using handgrip strength
assessment could be an appropriate use for clinical practice whilst the use of knee
flexors and extensors strength evaluation using a 1 repetition max test or
Dynamometers however the accessibility for these sports testing methods could be
limited. Rationalization and methods used to distinguish muscle strength in most
current years is skeletal muscle strength expressed through force production aptitude
in the muscle (Barbat-Artigas et al, 2012). Certainly there may be a robust connection
amongst muscle strength and functional deficiencies which encourages gaining an
understanding of its foundations and means. Different measures on assessing muscle
strength has been identified through the study of literature with each of these
measurements having both advantages and disadvantages, primarily depending on the
aim of the research and method used to asses muscle strength Barbat-Artigas et al,
2012). The analysis of supreme muscle strength is one of the most simplistic
techniques on stating what actual muscle strength would be as it would not require
various testing techniques. However, analysis of muscle strength is more relevant for
the use of understanding muscle function and injuries. Muscle strength primarily
depends on different variables that incorporate bodyweight, Body Mass Index (BMI),
muscle mass, acceleration and amplitude (Reed et al, 1991; Mitsionis et al, 2009).
Therefore the amendment of muscle strength around these variables may be of
relevance. Correspondingly to research conducted by Ploutzsnyder et al, (2002) they
theorized that amending muscle strength to body weight could be of importance when
regulating physical function threshold. Equally studies by Lynch et al, (1999), Tracy
et al, (1999) and Metter et al, (1999), all attempted on monitoring muscle strength on
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muscle mass which giving the categorization of muscle quality. Undeniably, stating
that muscle strength per unit of muscle mass could specify the influence it may have
to muscle quality (Barbat-Artigas et al, 2012).
Muscle power: another potential definition of muscle quality:
Definition: muscle power is observed as the capacity to execute muscle work per
unit. Maximal power is limited by the boundaries of force-velocity relation: maximal
isometric strength (or force; Fmax) and maximal velocity of contraction (Vmax)
(Power = Work/Time = Force*Distance/Time = Force*Speed) (Barbat-Artigas et al,
2012).
The ability to produce peak power is indomitable to the depth of muscle contraction
and the specific point in which it produces force, storage and depletion of elastic
energy, relations between contractile and elastics fundamentals (Cormie et al, 2011).
Additionally, maximal power production is induced through morphological elements
that are in incorporation with muscle fibre types that supply muscle structure, tendon
factors containing motor unit recruitment. Additionally, diverse modifications to
muscle atmosphere for example adjustments from fatigue alteration in muscle
temperature (Cormie et al, 2011). Considering this model form of corporation is
necessary on developing of muscle power, thus assessing muscle power may also
provide a respectable valuation of muscle quality. (Barbat-Artigas et al, 2012).
Remarkably Thom et al, 2007 stated that 10% of the adaptation on muscle power
could give an clarification as to why a reduction on muscle mass occurred in the body.
Thus, since the organization of muscle power results in a universal categorization of
neuromuscular factors which manipulates both muscle contraction rate and capacity
level of force produced in the muscle, with a lack of dissimilarity in the explanation of
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muscle mass and a decline in muscle power may be the cause of degeneration of
muscle quality (Barbat-Artigas et al, 2012).
Muscle power/Cross-sectional area (CSA):
As the same equation is used while assessing muscle strength, various studies all used
muscle power divided by the Cross-sectional area of the muscle (Haus, et al, 2007;
Toji et al, 2007; Thom et al, 2007). By dividing muscle power per unit by muscle
mass they could show a more complex calculation, however having a further
comprehensive guide of muscle quality as to dividing muscle strength per unit by
muscle size subsequently is also takes into account that a restriction on muscle
velocity.
Evaluation on Rectus Femoris analysis:
The most recent research that report on the operation of the quadriceps femoris
muscle throughout exercise has been done by Pocock, (1963) what he aimed on
investigating was chronological stage on when the three superficial muscles in the
quadriceps femoris mechanism during a number of different exercises that involved
the quadriceps femoris. Whereas, the adaptability of the appliance delivered resistive
loads, Electromyography (EMG) was measured using an effective knee extension
exercise. A research directed by Soderberg and Cook (1983), assessed quadriceps
scaling and straight leg raising test. The similarity of these two methods both had
produced respective measurements however; the validity of the testing was unreliable
due to the time scaling of the methods, thus in a lack of conclusion from the study was
reached. It was decided not to include using maximal exertion straight leg raise in
their assessment procedure, but it is not acknowledged that throughout the straight leg
raise test the contraction of the rectus femoris did not show a major influence on
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EMG, as consistent activity in the rectus femoris muscle. Allington, (1996),
conducted a research assessing 25 participants using maximal resisted isometric
contraction of the quadriceps femoris muscle on the completion of a knee extension.
Through a study conducted by Gough and Ladley (1971), exposed that in his straight
leg raise and isometric contraction test of the quadriceps femoris muscle testing there
was a excessive level of activity level during the isometric contraction in the
quadriceps. They had placed external electrodes on different parts of the quadriceps
such as the rectus femoris, vastus lateralis, and vastus medialis muscles. Knight et al
(1979), assessed which approach on assessing the quadriceps was more effective
whether the straight leg raise or knee extension had a greater on the development of
muscular strength in the quadriceps femoris. Though, a number of studies have shown
interest on actually specifying the function the vastus medialis muscle has in the
extension of the knee (Soderberg and Cook, 1983).
Ultrasound analysis on muscle quality:
There are numerous reports on the use of ultrasound assessment on muscle however it
is still yet to be proven the using ultrasound is the most accurate technique to analyse
muscle activity (Swigelaar et al, 2012). Hodler et al (2005) specified that the use of
ultrasound muscle analysis is merely somewhat precise on identifying fatty infiltration
in the muscle. Based on the study on ultrasound the limitations listed by Hodler et al
(2005), where that the use of ultrasound produced an inactive image of the muscle.
Khoury et al (2008) did an investigation on the comparison of the ultrasound and
Magnetic Resonance Imaging (MRI),, on the assessment of muscle size and fatty
penetration in the muscle. Whereas using ultrasound to identify fatty penetration in
the muscle by measuring the echogenicity.
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The use of ultrasound was used in a study by Swigelaar et al (2012) to assess the
rotary cuff in the shoulder and seemed to have produced a reliable source of data and
analysis.
The use of ultrasound is seen as an appropriate method used to examine ordinary and
pathological muscle tissue, as its images produced are non-invasive to the actual
muscle and the images are in simultaneous (Pillen, 2011). The use of ultrasound is a
simple method and has ease of access to use. Ultrasound imaging permits users to
view superficial appearance of soft muscle tissue (Pillen, 2011).
Summary: the use of muscle quality analysis within athletes is very limited in
previous researches and has shown now influence of the current method for testing
muscle quality being accurate on athletes of different sports. Even with a large
amount of research studies that look into the relationship of muscle mass and muscle
quality in individuals and present a weak base supporting the theory behind having a
greater mass of muscle producing a better form of muscle quality in the body. The
reason behind why this theory is used in a lot of studies on assessment muscle
strength diminishing (Watanabe et al, 2013).
Method
Subjects: 10 Male Rugby players, 10 Male football (Age: 18+) who are physically fit
and participate in rugby or football at the University of Bedfordshire, Bedford
Campus that trained or played and trained rugby or football at least once a week. Each
participant essentially participated in a single lab test at the Bedford Campus labs.
Through all lab sessions each participant would have to complete a Par-Q and a
consent form to ensure that they physically safe and fit to participate in the test.
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Equipment:
 Load cell,
 Vivid Echo ultrasound; Vivid 7, GE Healthcare, Horton, Norway,
 Photoshop PC
 IBM SPSS software version 21
Protocol: Participants were then briefed about the protocols, and questioned if their
skin was sensitive to anything that would be presented in the test or if they had any
type of allergies. This had to be done because a water-based gel would be used on
their skin to support the head of the ultrasounds movement on the skin of the
participants
(Vivid 7, GE Healthcare, Horton, Norway). The participants were then checked for
their blood pressure, because if participants had displayed a blood pressure of 130/40,
they would be deemed not be physically fit to participate on the test. Participants
were measured for the location of the leg to be scanned. To find the greatest contact
on which the entire representation of the Rectos Femoris could be pictured
participants were measured from the anterior superior iliac spine (iliac crest) to the top
of the patellar (knee) (Seymour et al, 2009). Then by attempting to find 3/5 of the
length found to obtain the most accurate image of the rectus femoris. The linear probe
was then set to 10L and superficial after being set it was then placed on the
participant’s leg, but the probe should not really make skin contact with the
participants’ skin. The role of the probe is to just hover over the skin by 1 centimetre
while it’s in interaction with the water-base gel. What the water-base gel does is
diminish acoustic disparity, which thus enhances picture quality. The probe was then
used to scan the leg and move constantly on the water-based gel at a gentle stable
pace in order to generate a good clear image on the ultrasound machine. Following,
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the images of the Rectus-Femoris are captured on the Vivid Ultrasound machine and
saved. At this stage the first stage of the testing is finished and we can move on to the
second phase.
The second phase of the testing involved a knee extension strength test. Before
commencing the second phase of the test participants would warm up the quadriceps
by performing a squats repetition of 3 sets of 10 repetition, The knee strength test
involves using a tension gage method that connects from the chair to the participants
lower leg around the ankle area. Participants were sat on the chair with both their hips
and knees bent at a 90° angle. The legs 90° was determined by the location the gage
and was given and connected to the participants leg. Then the force production would
be tested on participants both dominant and non-dominant legs, through isometric
contraction. The chair is to be adjusted so that the participants’ foot hover's off of the
ground, it is done like this because if the participants feet rest on the floor it could
assist in generating more force than their leg may usually be capable of producing.
The strapping around the ankle will be attached to the force transducer that was
placed underneath the chair. The participants were then be counted down from 3 to 1,
and then asked to kick as hard as possible. With the cuff strapped around the ankle the
forced produced from the kick will be transferred through a wire to the force
transducer, from the kick they were asked to produce a full maximum isometric
contraction of the quadriceps, this was done over the period of 3 to 5 seconds. After 3
to 5 seconds of continuous maximum effort isometric contraction, of the quadriceps -
the test will be repeated 5 times on each participants leg dominant and non-dominant
leg with a rest of 30 seconds in between each attempt and the highest value of force
produced would be used. Subsequently images captured using the Vivid Ultrasound
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have been analysed for the Cross-Sectional Area (CSA) of the Rectus Femoris muscle
using Photoshop software to analyse the images.
Figure 1. Shows the Cross-Sectional area of the Rectus Femoris.
Photoshop PC analysis procedure: after uploading pictures obtained from the Vivid
ultrasound machine it was then uploaded on to the Photoshop software where the
cross-sectional area of the rectus femoris was then analysed.
Step by step procedure of the photoshop:
1. Upload Ultrasound images on Photoshop software
2. Select two images that match and complete the rectus femoris
3. Cut the right side of the image and paste on the other image
4. Align pictures so they match and create one complete image of the rectus
femoris
5. Then set a measuring scale for the image to be analysed (centimetres)
6. Highlight the cross-sectional area of the rectus femoris to be analysed
7. Select for the highlighted cross-sectional area to be calculated
8. Cross-sectional area record will be produced
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Muscle Quality equation: The calculation to find muscle quality is peak force
generated divided by the Cross-Sectional Area (CSA) of a muscle in this case the
Cross-Sectional Area of the Rectus Femoris (Barbat-Artigas et al, 2013).
Statistical analyses: Statistical analysis was performed using IBM SPSS statistics (version
21). The values presented are the mean ± standard deviation. Correlations amongst athletes
dominant and non-dominant leg muscle quality calculation generated from rugby and football
players. peak force generated from the seated leg extension test and the Rectus Femoris
Cross-Sectional area where calculated using the muscle quality calculation which is peak
force produced divided by Pearson’s correlations coefficient. An Independent sample T-Test
was performed to assess the independent link between athletes peak force generated and the
Rectus Femoris Cross-Sectional area. Therefore, purely only these two variables were used as
illustrative variables. Statistical impact was well defined as level of significance will be
accepted at P≤0.05 in all circumstances
Results
To identify muscle the calculation used peak force generated (Newton's) divided by
the Cross-Sectional Area of a muscle (Centimeters) in this case the Cross-Sectional
Area of the Rectus Femoris (Barbat-Artigas et al, 2013).
Table 1. Shows Mean and Standard Deviation of the highest muscle quality
Maximum
value muscle
Quality
calculation
Groups N Mean Std. Deviation
Rugby players 10 49.06 10.38
Football players 10 46.32 6.64
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calculation value of both rugby and football and rugby player.
Value of muscle
Quality
calculation in
Dominant leg
Groups N Mean Std. Deviation
Rugby players 10 52.14 12.54
Football players 10 47.34 6.55
Table 2. Shows Mean and Standard Deviation of muscle quality calculation in rugby
and football players’ dominant leg.
Value of muscle
Quality calculation
in non dominant leg
Groups N Mean Std. Deviation
Rugby players 10 42.94 15.92
Football players 10 43.09 4.71
Table 3. Shows Mean and Standard Deviation of muscle quality calculation in rugby
and football players’ non-dominant leg.
Peak force
generated in
dominant leg
Groups N Mean Std. Deviation
Rugby players 10 576.80 141.21
Football players 10 525.20 119.88
Table 4. Shows Mean and Standard Deviation of peak force generated in dominant leg
in rugby and football players’
Peak force
generated in non-
dominant leg
Groups N Mean Std. Deviation
Rugby players 10 474.80 181.86
Football players 10 467.20 63.44
Table 5. Shows Mean and Standard Deviation of generated in non-dominant leg in
rugby and football players
Cross-sectional area
of rectus femoris in
dominant leg
Groups N Mean Std. Deviation
Rugby players 10 11.76 2.08
Football players 10 11.32 1.67
Table 6. Shows Mean and Standard Deviation of the Cross-sectional area of rectus
femoris in dominant leg of rugby and football players’.
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Cross-sectional area
of rectus femoris in
non-dominant leg
Groups N Mean Std. Deviation
Rugby players 10 11.04 1.63
Football players 10 10.93 1.66
Table 7. Shows Mean and Standard Deviation of the Cross-sectional area of rectus
femoris in non-dominant leg of rugby and football players’.
Descriptive statistics: Table 1 shows a significant difference in the highest values of
muscle quality calculation between rugby and football players. (P>0.05.) P = 0.006
using an independent sample T-test; (t= 1.072), df 18. Tables in the appendix will
show the details of these figures.
Table 2 shows a non-significant difference in the values of muscle quality calculation
on dominant leg between rugby and football players. (P>0.05.) P = 0.091 using an
independent sample T-test; (t= 0.701), df =18. Tables in the appendix will show the
details of these figures.
Table 3 shows a significant difference in the values of muscle quality calculation on
non-dominant leg between rugby and football players (P<0.05.) P = 0.000 using an
independent sample T-test; (t= -.029), df =18. Tables in the appendix will show the
details of these figures.
Table 4 shows a non-significant difference in the values of peak force generated in
dominant leg between rugby and football players’. (P>0.05.) P = 0.477 using an
independent sample T-test; (t=0.881), df 18. Tables in the appendix will show the
details of these figures.
Table 5 shows a significant difference in the values of peak force generated in non-
dominant leg between rugby and football players. (P<0.05.) P = 0.005 using an
independent sample T-test; (t= 0.125), df 18. Tables in the appendix will show the
details of these figures.
Table 6 shows a non-significant difference in values of the Cross-sectional area of the
15

rectus femoris in dominant leg of rugby and football players’. (P>0.05.) P = 0.320
using an independent sample T-test; (t= 0.515), df 18. Tables in the appendix will
show the details of these figures.
Table 7 shows a non-significant difference in the values of the Cross-sectional area
of the rectus femoris in non-dominant leg between rugby and football players’.
(P>0.05.) P = 0.898 using an independent sample T-test; (t= 0.148), df 18. Tables in
the appendix will show the details of these figures.
Discussion:
Main findings:
Results presented in this study show that there was a significant difference in muscle
quality production in rugby players and football players. (P>0.05.) P = 0.006 using
an independent sample T-test; (t= 1.072), df 18. Results also identified that there was
a significant difference between the values of muscle quality calculation on non-
dominant leg of rugby and football players (P<0.05.) P = 0.000 using an independent
sample T-test; (t= -.029), df =18. The results also identified that there was a
significant difference in the values of peak force generated in non-dominant leg
between rugby and football players. (P<0.05.) P = 0.005 using an independent
sample T-test; (t= 0.125), df 18.
Based on anatomical data this study produced, it showed that rugby players tend to
produce a better form of muscle quality in the rectus femoris than football players,
thus assuming that training methods used by rugby players may benefit athletes on the
production of better muscle size and muscle strength in the quadriceps as to the
method used by footballers. Of the data collected through evaluating the force
productivity level of the Rectus femoris and the Cross-sectional area of the rectus
femoris it shown that there was a significant difference in muscle quality production
16

between both sports, difference on the muscle quality quantity on rugby players non-
dominant leg on comparison to the football players and also the amount of force
produced by rugby players compared to football players.
Of the rest of the data collected in the studies other results showed no significant
difference on the cross-sectional area of the rectus femoris in dominant and non-
dominant leg between rugby and football players and also the muscle quality value on
the rugby and football players’ dominant leg. Hence these results also propose that
there are no difference in the cross sectional area of the rectus femoris between
athletes from both sports and the muscle quality in the athletes dominant leg.
At the current moment there seems to be a major lack in studies that have either
attempted to compare athletes muscle quality or the comparison of different sport
athletes and the muscle quality the obtain. The rectus femoris is a muscle of great
importance to functional abilities of the leg in the human body and especially athletes
that require the use of a strong quadriceps.
Although with the results of the study it has found three significant difference
between the muscle quality production, peak force production in non-dominant leg
and highest values of muscle quality in the non dominant legs for the rugby and
football players, however there may be a abnormality between sports and also a
tendency for rugby players to produce a higher percentage of force production in the
dominant leg than footballers.
Muscle Quality in Football players: although some testing from this study shows
that rugby players may produce a superior force production and muscle quality in the
17

quadriceps in some way this still does not indicate whether which sports specific
training produces a greater quality in muscle as through performance the quadriceps
in both sports have to different requirements for example the same amount of distance
covered through running over a 90 minute period of a game would not be the same as
football players that play in Central midfield or full backs would require to have
vaster muscle endurance as supposed to muscles that generate an abundant of strength
in the quadriceps.
Muscle Quality in rugby players: superior force production in rugby players is of
great importance to rugby players performance and training as the sport requires a lot
of explosive strength production in both their training muscle development and during
80 minutes of a rugby game however with rugby performance there may seem to be a
lot of use of explosive strength but not really a lot of muscular endurance is required
as they do not cover as much distance running meaning that footballers would
necessitate having a more long enduring muscular endurance as supposed to explosive
muscular strength.
Therefore although this study has identified that rugby players may produce a more
powerful set of quadriceps there are no concrete evidence that associates with rugby
players’ vast force productivity level in the quadriceps but may also lack on a high
level of muscular endurance that athletes through other sports may provide a greater
muscular endurance strength and who’s to say that may not be the true definition of
muscle quality.
Limitations of Study:
This study had various potential limitations. For this study two different participant
conducted collection for this study so two different assessors executed the profundity
of each ultrasound image. Although measurement consistency may have predisposed
18

the values if the muscle cross-sectional area, former studies have suggested that a
single person measuring the images increases the reliability levels of the
measurements O’Sullivan et al (2007), by also recommending several recurring
quantities of the same image would reduce disturbance of the results. The cross-
sectional area measurements of numerous muscles have been accomplished in various
different methods over a wide range of previous researches. In this study, to uncover
the highest image representation of the Rectus femoris was by measuring the
participants from the anterior superior iliac spine (iliac crest) to the top of the patellar
(knee) (Seymour et al, 2009) then by attempting to find three fifth of the length found
to obtain the most accurate image of the rectus femoris. This method of obtaining the
location of the rectus femoris does not take into account the size of the whole rectus
femoris muscle, which is proposed to associate best to muscle power in the quadriceps
and also that it may vary in different participants. Currently there is a limited form of
research that assists on the correct method to obtain the most accurate measurement of
the cross-sectional area of a muscle using ultrasound or MRI scanning. Reflecting on
the seated position on the for seated load cell force production test the reliability of
the test may vary as some participants may struggle and find it easier than others as to
some participants were taller than others. Although while participants were
encouraged to obtain a correct posture in the seated examination, many of the
participants had tendencies to attempt to cheat by holding on to the chair or slanting to
the side to assist them on producing a higher force value in the quadriceps.
Conclusion
The current study shows that association between muscle quality production in the
quadriceps and strength between rugby and football players showed a significant
difference between three different of testing difference. The outcomes of this study
19

suggest that the level of muscle quality and strength developed in rugby are of a
higher productivity in comparison to football players.
Though there is various evidence on the analysis of muscle quality in individuals there
is various evidence on the relationship of muscle force production, muscle mass and
identifying muscle quality in elderly individuals there is a major lack in research in
identifying muscle quality in young adult individuals. Additionally there is no current
research that attempt to identify muscle quality production in athletes and forms of
developing a sports specific muscle quality identification model.
To conclude on this research that analysis of muscle quality in individuals is of great
importance to scientists of doctors. Although the definition of muscle quality has been
produced there are some faults on identifying muscle quality in athletes of different
sports, for example what is the true definition of muscle quality in athletes;
 Who perform long muscular endurance exercise
 Who perform in short explosive sports
Until these factors of muscle quality have been identified for sports specific
individuals a use of attempting to identify muscle quality in sports individuals may
encounter some difficulties.
Recommendations for Future Research:
Exploring the difference in limb dominance in sports performance and to also
investigate a more sports specific muscle quality index as the current equation to
identify muscle quality in individuals is not of a sports specific and more general
identification and feel that it does not identify what true muscle quality in individuals.
20

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27

Sport Number of
participants
Peak force
production fro
dominant
(Newton's)
Peak force
production from
non-dominant leg
(Newton's)
Cross-sectional
area of rectus
femoris in non-
dominant leg
(Centimetres )
Cross-sectional
area of rectus
femoris in
dominant leg
(Centimetres)
Dominant leg
muscle quality =
Peak force
production
÷Cross-sectional
area of muscle
Non-Dominant leg
muscle quality =
Peak force
production
÷Cross-sectional
area of muscle
Rugby 1 626 288 11.04 11.03 56.75430644 26.08695652
2 698 656 10.4 13.8 50.57971014 63.07692308
3 563 383 9.9 13.4 42.01492537 38.68686869
4 665 530 13.4 11.3 58.84955752 39.55223881
5 614 490 14.3 14.7 41.76870748 34.26573427
6 704 617 10.7 13.8 51.01449275 57.6635514
7 344 253 9.1 9.3 36.98924731 27.8021978
8 300 230 9.9 9.2 32.60869565 23.23232323
9 649 767 11.5 11.8 55 66.69565217
10 605 534 10.2 9.3 65.05376344 52.35294118
Football 11 502 462 10.7 11.07 45.34778681 43.08411215
12 459 380 9.06 9.16 50.10917031 41.94260486
13 838 542 11.93 13.37 62.6776365 45.43168483
14 432 385 7.36 8.62 50.11600928 52.30978261
15 535 498 12.6 12.86 41.60186625 39.52380952
16 492 442 11.4 11.3 43.53982301 38.77192982
17 582 511 13 13,7 42.48175182 39.30769231
18 426 462 10.9 10.7 39.81308411 42.3853211
19 521 570 11.5 11.8 44.15254237 49.56521739
20 465 421 10.9 10.7 43.45794393 38.62385321
Appendix:
28

Group Statistics
Groups N Mean Std. Deviation Std. Error Mean
Dominant_leg_muscle_Quality Rugby players 10 49.0633 10.38907 3.28531
Football players 10 46.3298 6.64359 2.10089
Independent Samples Test
Levene's Test for
Equality of
Variances
t-test for Equality of Means
F Sig. t df Sig. (2-
tailed)
Mean
Difference
Std. Error
Difference
95% Confidence Interval
of the Difference
Lower Upper
Dominant_leg_muscle_Quality
Equal variances
assumed
3.197 .091 .701 18 .492 2.73358 3.89962 -5.45921 10.92637
Equal variances
not assumed
.701 15.306 .494 2.73358 3.89962 -5.56380 11.03096
Group Statistics
Groups N Mean Std. Deviation Std. Error Mean
Nom_Dominant_leg_muscle_Qu
ality
Rugby players 10 42.9415 15.92201 5.03498
Football players 10 43.0946 4.71222 1.49013
29

Independent Samples Test
Levene's Test for
Equality of Variances
t-test for Equality of Means
F Sig. t df Sig. (2-
tailed)
Mean
Difference
Std. Error
Difference
95% Confidence
Interval of the
Difference
Lower Upper
Nom_Dominant_leg_muscle_Quality
Equal variances
assumed
17.976 .000 -.029 18 .977 -.15306 5.25086 -11.18471 10.87859
Equal variances not
assumed
-.029 10.565 .977 -.15306 5.25086 -11.76850 11.46238
Group Statistics
Groups N Mean Std. Deviation Std. Error Mean
30

highest_leg_muscle_Quality Rugby players 10 52.1475 12.54399 3.96676
Football players 10 47.3476 6.55845 2.07396
Independent Samples Test
Levene's Test for
Equality of Variances
t-test for Equality of Means
F Sig. t df Sig. (2-
tailed)
Mean
Difference
Std. Error
Difference
95% Confidence
Interval of the
Difference
Lower Upper
highest_leg_muscle_Quality
Equal variances
assumed
9.818 .006 1.072 18 .298 4.79990 4.47621 -4.60428 14.20408
Equal variances not
assumed
1.072 13.578 .302 4.79990 4.47621 -4.82867 14.42848
Group Statistics
Groups N Mean Std. Deviation Std. Error Mean
31

Peak_force_generated_between_
dominant_leg
Rugby players 10 576.8000 141.21127 44.65492
Football players 10 525.2000 119.88773 37.91183
Independent Samples Test
Levene's Test for
Equality of
Variances
t-test for Equality of Means
F Sig. t df Sig. (2-
tailed)
Mean
Difference
Std. Error
Difference
95% Confidence
Interval of the
Difference
Lower Upper
Cross_sectional_area_of_dominant_leg_rectus_femoris
Equal variances
assumed
1.047 .320 .515 18 .613 .43500 .84535 -
1.34100
2.21100
Equal variances
not assumed
.515 17.207 .613 .43500 .84535 -
1.34689
2.21689
32

Group Statistics
Groups N Mean Std. Deviation Std. Error Mean
Peak_force_generated_between_
non_dominant_leg
Rugby players 10 474.8000 181.86124 57.50957
Football players 10 467.2000 63.44341 20.06257
Independent Samples Test
Levene's Test for
Equality of
Variances
t-test for Equality of Means
F Sig. t df Sig. (2-
tailed)
Mean
Difference
Std. Error
Difference
95% Confidence
Interval of the
Difference
Lower Upper
Peak_force_generated_between_non_dominant_leg
Equal variances
assumed
10.137 .005 .125 18 .902 7.60000 60.90860 -
120.36422
135.56422
Equal variances
not assumed
.125 11.159 .903 7.60000 60.90860 -
126.22677
141.42677
Group Statistics
Groups N Mean Std. Deviation Std. Error Mean
33

Cross_sectional_area_of_non_do
minant_leg_rectus_femoris
Rugby players 10 11.0440 1.63307 .51642
Football players 10 10.9350 1.66386 .52616
Independent Samples Test
Levene's Test
for Equality of
Variances
t-test for Equality of Means
F Sig. t df Sig.
(2-
tailed)
Mean
Difference
Std. Error
Difference
95% Confidence
Interval of the
Difference
Lower Upper
Cross_sectional_area_of_non_dominant_leg_rectus_femoris
Equal variances
assumed
.017 .898 .148 18 .884 .10900 .73725 -
1.43990
1.65790
Equal variances
not assumed
.148 17.994 .884 .10900 .73725 -
1.43994
1.65794
Group Statistics
Groups N Mean Std. Deviation Std. Error Mean
Cross_sectional_area_of_domina
nt_leg_rectus_femoris
Rugby players 10 11.7630 2.08325 .65878
Football players 10 11.3280 1.67516 .52973
34

Independent Samples Test
Levene's Test for
Equality of
Variances
t-test for Equality of Means
F Sig. t df Sig. (2-
tailed)
Mean
Difference
Std. Error
Difference
95% Confidence
Interval of the
Difference
Lower Upper
Cross_sectional_area_of_dominant_leg_rectus_femoris
Equal variances
assumed
1.047 .320 .515 18 .613 .43500 .84535 -
1.34100
2.21100
Equal variances
not assumed
.515 17.207 .613 .43500 .84535 -
1.34689
2.21689
35

INFORMATION SHEET
To analyse the difference in the cross-sectional area and muscle strength in the upper leg
muscle of rugby players and football players
Dear Participant,
Thank you for showing an interest in participating in the study. Please read this information
sheet carefully before deciding whether to participate. If you decide to volunteer we thank you
for your participation. If you decide not to take part there will be no disadvantage to you of any
kind and we thank you for considering our request.
What is the aim of the project?
The purpose of the study is to compare the size of muscle and muscle strength between Rugby
and Football players. As it has never been determined to what extent the difference is.
What type of participant is needed?
Male, healthy Rugby or Football players for at least six years over eighteen years of age.
What will participants be asked to do?
You will be asked to visit the Sport and Exercise Science Laboratories on one occasion. This
visit should last no longer than sixty minutes. On arrival at the laboratories you will be asked
to complete a PARQ and consent form, you will then be asked to remove your shoes and have
your height and body mass measured. You will be asked to wear a pair of shorts that are easily
rolled up. A water based gel will then be placed on the quad and an ultrasound picture will be
taken, whilst you are sitting in a chair. You will then be asked to sit in a different chair with
either your right or left leg in a cuff and you will be asked to push against the cuff as hard as
you can for 3 seconds. The procedure will then be repeated on the other leg. The cuff will then
be released from the ankle and that will be the end of the visit.
What are the possible risks of taking part in the study?
There are no risks associated with height and body mass measurements. There are currently no
known adverse effects of ultrasound scanning. You may become tired from staying in a seated
position and may suffer an allergic reaction from the gel. However this is unlikely as it is a
water based gel. There could also be a risk of injury from the max leg extension, the injuries
that could be obtained are mainly muscle strains.
What if you decide you want to withdraw from the project?
36

If, at any stage you wish to leave the project, then you can. There is no problem should you
wish to stop taking part and it is entirely up to you. There will be no disadvantage to yourself
should you wish to withdraw.
What will happen to the data and information collected?
Everyone that takes part in the study will receive their own results for the tests that they
complete. All information and results collected will be held securely at the University of
Bedfordshire and will only be accessible to related University staff. Results of this project may
be published, but any data included will in no way be linked to any specific participant. Your
anonymity will be preserved.
What if I have any questions?
Questions are always welcome and you should feel free to ask myself Reinaldo Camuimba or
Laura Charalambous (Supervisor) any questions at anytime. See details below for specific
contact details.
Should you want to participate in this study then please complete the attached consent form,
which needs to be returned before commencing the study.
This project has been reviewed and approved by the Ethics Committee of the Department of
Sport and Exercise Sciences.
Many Thanks,
Reinaldo Camuimba Laura Charalambous
Department of Sport and Exercise Sciences, Email: [e-mail]
University of Bedfordshire
Bedford Campus,
Polhill Avenue,
Bedford
Email: [e-mail]
37

CONSENT FORM
TO BE COMPLETED BY PARTICIPANT
NAME:…………………………………………………(Participant)
I have read the Information Sheet concerning this project and understand what it is about. All
my further questions have been answered to my satisfaction. I understand that I am free to
request further information at any stage.
I know that:
- My participation in the project is entirely voluntary and I am free to withdraw
from the project at any time without disadvantage or prejudice.
- I will be required to attend one session of approximately one hour to complete the project.
As part of the study I will have to:
- Wear shorts in order for an ultrasound scan of the Rectus Femoris.
- Have girth measurements of upper leg (quadriceps) taken.
- Be calm and sit stationary in order for the ultrasound measurements to be taken - An isometric
leg extension will be done.
- I am aware of any risks that may be involved with the project.
- All information and data collected will be held securely at the University indefinitely. The
results of the study may be published but my anonymity will be preserved.
Signed:………………………………… (Participant) Date: …………………
38

A PAR-Q form
39

40

41

42