the relationship between core - hkbu

AN HONOURS PROJECT SUBMITTED IN PARTIAL FULFILMENT OF

THE REQUIREMENTS FOR THE DEGREE OF

BACHELOR OF ARTS

IN

PHYSICAL EDUCATION AND RECREATION MANAGEMENT (HONOURS)

HONG KONG BAPTIST UNIVERSITY

APRIL 2011

THE RELATIONSHIP BETWEEN CORE

MUSCLES FUNCTION AND PERFORMANCE IN

LONG DISTANCE RUNNERS

BY

GI KA MAN 08024529

2

HONG KONG BAPTIST UNIVERSITY

APRIL 2011

We hereby recommend that the Honors Project by Mr.

Gi Ka man entitled: “The relationship between core

muscles function and performance in long distance

runners” to be accepted in partial fulfillment of the

requirements for the Bachelor of Arts Honors Degree in

Physical Education and Recreation Management.

Dr. Tom Tong

Chief Advisor

Dr. Patrick Lau

Second Reader

Process Grade:

Product Grade:

Overall Grade:

3

ACKNOWLEDGEMENTS

I would like to take this opportunity to express

my sincere thanks to all people who had provided support

to my study. Foremost among them is my supervisor, Dr.

Tom Tong, whose valuable guidance and suggestions were

of great value to me. Besides, I must thank Professor

Chung, Head of the Department, for his encouragement

in my study. I would also like to thank my second reader,

Dr. Patrick Lau, for reviewing my project. Last but not

least, my heartfelt thanks go to all the runners

participated in this study, for their kind cooperation

and understanding.

Gi Ka Man

Department of Physical Education

Hong Kong Baptist University

4

ABSTRACT

The purpose of this study was to identify the

relationship between core muscles function and

performance in long distance runners. The participants

were 51 Hong Kong Chinese male long distance runners

with a mean age of 22.24 years (ranged from 16 to 36

years-old). The Modified Plank Test was used to examine

the core muscles function of participants. Their

performance in the Standard Chartered Hong Kong

Marathon 2011 – 10 km Race was recorded. The

relationships between the two Modified Plank Test

results and the results in the Standard Chartered Hong

Kong Marathon 2011 – 10 km Race were high and negative

(r ranged from -.60 to -.63, p < .01).The findings of

this study suggested that runners with better core

muscles function tended to have better running

performance in 10 km race.

5

TABLE OF CONTENTS

Page

ACKNOWLEDGEMENTS…………………………………………... 3

ABSTRACT…………………………………………...................... 4

TABLE OF CONTENTS………………………….………………... 5

LIST OF TABLES…………………………………………........... 8

LIST OF FIGURES…………………………………………........ 9

CHAPTER 1

INTRODUCTION…………………………………………............. 10

Background of Study…………………………………… 10

Statement of the Problems…………………………… 11

Purpose of the Study…………………………………… 12

Significance of the Study…………………………… 12

CHAPTER 2

REVIEW OF LITERATURE……………………………………… 13

Anatomy and Functions of Core Muscles…………… 13

Methods of Assessing Core Muscles

Function………………………………………….................. 17

The Role of Core Muscles in Sport-specific

Performance…………………………………………........... 23

Summary…………………………………………..................... 28

Research Hypothesis …………………………………… 29

6

Page

CHAPTER 3

METHODOLOGY…………………………………………............... 30

Participants……………………………………………... 30

Research Design…………………………………………... 31

Definition of Terms…………………………………… 32

Procedures………………………………………….............. 32

Test protocol…………………………………………........ 34

Delimitations…………………………………………….. 36

Assumptions…….………………………………………….. 37

Methods of Analysis…………………………………… 37

CHAPTER 4

ANALYSIS OF DATA……………………………...……………... 40

Results……………………………………………………..... 40

Discussion………………………………………….............. 53

Limitations………………………………………………... 57

CHAPTER 5

SUMMARY AND CONCLUSIONS………………………………... 58

Summary……………………………………..………………... 58

Conclusions………………………………………………... 59

Recommendations for Further Study……………… 59

7

Page

REFERENCES………………………………………….................. 61

APPENDIX…………………………………………...................... 70

A. Physical Activity Readiness

Questionnaire……………………………………….. 70

B. Written Inform Consent Form…………………… 71

C. Record Sheet………………………………………….... 74

D. Pictorial Illustration of the Modified

Plank Test………………………………………......... 75

CURRICULUM VITAE…………………………………………..... 78

8

LIST OF TABLES

Table Page

1. Demographic Information of the Participants

(N = 51) ……...…………………………………….............. 41

2. Summary of Intercorrelation for the Modified

Plank Test and Variables Related to Running

Performance (N = 51) ………………………………… 46

3. Comparison between the Junior Group (n = 21)

and the Senior Group (n = 30) ……………………. 50

9

LIST OF FIGURES

Figure Page

1. Scatter plot for results in the Standard

Chartered Hong Kong Marathon 2011 – 10 km Race

and results in the first trial of the Modified

Plank Test (N = 51)………………………………… 47

2. Scatter plot for results in the Standard

Chartered Hong Kong Marathon 2011 – 10 km Race

and results in the second trial of the

Modified Plank Test (N = 51)……………………… 48

3. Modified Plank Test results (min) for the

Junior Group and the Senior Group…………… 51

10

CHAPTER 1

INTRODUCTION

Background of Study

Core muscles training was popular in the health and

fitness industry. Exercises that focused on the

training of abdominals, hip, and back muscles were

common in most strength and endurance workouts. It was

believed that stronger core muscles would contributed

to health-related and sport-related benefits. For

instance, it was found that strong core muscles improved

athletic performance and helped prevent injury (McGill,

2001; Olmsted, Carcia, Hertel, & Shultz, 2002).

Despite this strong belief, there was no concrete

evidence demonstrating the relationship between core

muscles function and sports performance. Further, there

was little information showing the role of core muscles

in endurance sports in a quantitative way. In running,

core muscles training was an important component in the

workout packages of many long distance runners. Apart

from running drills, core muscles training was commonly

incorporated into the training schedules. It was

believed that stronger core muscles were essential to

maintain optimal ground reaction forces and adequate

dynamic stability of the lower extremity which were both

important to long distance running (Sato & Mokha, 2009).

11

Based on these connections, a clearer understanding

about the role of core muscles in long distance running

would be desirable. Therefore, the purpose of this study

was to identify the relationship between core muscles

function and performance in long distance runners. With

the information provided in this study, the importance

of core muscles to running performance would be

identified. The coaches and athletes would be able to

revisit the contents of their training programs.

Statement of the Problems

Core muscle training was commonly applied in long

distance run training programs. However, whether core

muscles function was related to the performance of long

distance running was not well known. The problem of

the study was to evaluate the core muscles function

of Hong Kong Chinese male long distance runners by

conducting modified plank test. Included in this study

was an attempt to identify the relationship between

long distance runners’ core muscles function and their

self-reported results in their results in the Standard

Chartered Hong Kong Marathon 2011 – 10 km Race.

12

Purpose of the Study

The purpose of this study was to examine the


performance in long distance runners. This would

determine the importance of core muscles to long

distance running.

Significance of the Study

Developing core muscles was becoming a common

element in sports training. For long distance runners,

workouts for core muscles were usual in ordinary

training routines. However, scientific evidence of

supporting the emphasis on core muscles training was

limited. The relationship between core muscles function

and performance in running sports was not well

established. The focus of this study was to provide

information on the relationship between core muscles

function and performance in long distance runner. This

information provided coaches, runners, and

practitioners with a clearer picture about the role of

core muscles in overall performance in long distance

running. Based on the information obtained in this study,

the coaches, runners, and practitioners would gain more

insights in developing effective training plans.

13

CHAPTER 2

REVIEW OF LITERATURE

In this study, the objective of literature review

was to present previous studies which related to the

issues about core muscles functions. This chapter

included: (a) anatomy and functions of core muscles,

(b) methods of assessing core muscles function, (c) the

role of core muscles in sport-specific performance, (d)

summary, and (e) research hypotheses.

Anatomy and Functions of Core Muscles

Core muscles were an important muscle group to

human beings. Several models were published to describe

the musculature of the core (Hibbs, Thompson, French,

Wrigley, & Spears, 2008). This muscle group was the

muscles in the abdomen, pelvic floor, sides of the trunk,

back, buttocks, hip, and pelvis (Fahey, Insel, & Roth,

2007, p. 155). Major muscles included are the pelvic

floor muscles, transversus abdominis, multifidus,

external and internal obliques, rectus abdominis, and

erector spinae (sacrospinalis). Minor core muscles

included the latissimus dorsi, gluteus maximus, and

trapezius.

The anatomy and function of major muscles were

discussed in this section. Pelvic floor muscles

consisted of levator ani and coccygeus. They helped

14

support and maintain position of pelvic viscera

(Tortora, 2005, p. 324). Transversus abdominis was the

deepest muscle of the abdominal wall, its main function

was to compress abdominal contents (Marieb, 1998, p.

324). Multifidus was one of the deepest muscles of the

back, it functioned as an aid to extend the vertebral

column (Tortora, 2005, p. 354). External and internal

obliques were muscles of the abdominal wall. External

oblique located inferior to the serratus anterior

muscle (Tortora, 2005, p. 391) while the internal

oblique was the intermediate flat muscle (Tortora, 2005,

p. 317). Their function was to compress abdomen and flex

vertebral column (Tortora, 2005, p. 318). Rectus

abdominis referred to the medial superficial muscle

pair, it extended from the pubis to the rib cage. It

was ensheathed by aponeuroses of lateral muscles and

segmented by three reinforcing tendinous intersections

(Marieb, 1998, p. 324). It was a key muscle to flex and

rotate lumbar region of vertebral column (Marieb, 1998,

p. 324).

Erector spinae was also called sacrospinalis,

including iliocostalis, longissimus, and spinalis.

They formed the intermediate layer of intrinsic back

muscles and provided resistance that helped control

action of bending forward at the waist and acted as the

15

powerful extensors to promote return to erect position

(Marieb, 1998, p. 320).

The core muscles served important functions to

human movements. They acted as a bridge that helped

transfer force between the upper body and the lower body.

For instance, when hitting a forehand in tennis, most

of the force was transferred from the lower extremity,

through the core, to the arms (Fahey, Insel, & Roth,

2007).

Several studies demonstrated the role of core

muscles in preventing injury, especially back pain.

Strong core muscles stabilized the spine and reduced

unnecessary movement intersegmentally (Carter, Beam,

McMahan, Barr, & Brown, 2006). This helped decrease the

risk of back pain by promoting a reduction in tissue

strain, deformation, compression, and overstretching.

The benefits of strong core muscles were also mentioned

in another study (Willson, Dougherty, Ireland, & Davis,

2005). Core muscles were essential to the

musculoskeletal system. They maintained low back health

and prevented knee ligament injury.

More specifically, a study conducted by Richardson

et al. (2002) showed that strong transversus abdominis,

one of the major muscles of the core, reduced the

occurrence of low back pain. Whittaker (2004) explored

16

the relationship between pelvic floor muscles and low

back pain. It was found that better pelvic floor motor

control contributed to better back health and therefore

reduced the chance of having lumbopelvic dysfunction.

Reid and Mcnair (2000) identified the factors

contributing low back pain in rowers. It was suggested

that the fatigue of erector spinae muscles might incur

low back injury. Therefore, core muscles training were

recommended to rowers.

Based on the above, a clear relationship between

core muscles and body health was well established. This

explained the high popularity of core muscles training

in health and rehabilitation settings.

17

Methods of Assessing Core Muscles Function

Although core muscles performed important

functions, a standardized and well recognized method

of assessing core muscles function was yet to be

confirmed. This section reviewed some common methods

of examining core muscles function. A typical fitness

test for abdominal endurance was the Sit-up Test

(Pollock, Wilmore, & Fox, 1978). The starting position

was to have the participants assumed a supine position

on the exercise mat with the knees flexed, feet flat

on the floor. The arms crossed on the chest with the

hands placing on the opposite shoulders. The feet of

the participants were anchored by a test partner. On

the “Go” command, the participants curled to a sitting

position and touched the thighs with the elbows. Then

the participants curled back to the starting position.

The score was the number of sit-ups properly performed

in 1 minute. Although the Sit-up Test was easy to be

administered, McGill (1995) determined that the Sit-up

Test would stress compressive load to participants and

suggested that this test might trigger low back pain.

The Front Abdominal Power Test was developed by

Cowley and Swensen (2008). This test was adapted from

plyometric medicine ball training. The testing area was

a 10 m x 3 m space with no obstacles. An exercise mat

18

was placed on the floor parallel to the testing area.

The end of the exercise mat was aligned with a piece

of tape that was placed on the floor.

As for the starting position, the participants

were asked to lay with their back on the mat with arms

aside and feet shoulder width apart. They assumed a

supine position on the exercise mat with the knees at

90 degrees and the arms were put over their head. Further,

the tips of the feet were aligned with the end of the

exercise mat, with shoulders flexed, elbows and wrists

extended, hands supinated with left and right thumbs

touching. A 2-kg medicine ball was then placed on the

participants’ hands. They were instructed to cradle the

ball. The participants were asked to keep the shoulders,

elbows, and wrists locked in this position with the

medicine ball securely grasped in the hands.

The participants were then asked to execute an

explosive concentric contraction of the abdominal and

hip flexor muscles, while using the arms as a lever to

release the medicine ball. The score was the distance

between the landing point of the medicine ball and the

tip of the feet. Based on the study conducted by Cowley

and Swensen (2008), the Front Abdominal Power Test was

found to be a reliable test that could be used to examine

the power component of core muscles.

19

The Biering-Sorensen test (Biering-Sorenson, 1984)

was another method to assess lumbar extension, one of

the important functions of the core muscles. It was a

popular isometric measure of back muscle endurance.

Under the Biering-Sorensen test, the participants were

instructed to perform the “Biering-Sorensen position”

with the upper body cantilevered out over the end of

a test bench and with the pelvis, knees, and hips secured.

The upper body was held across the chest with the hands

placing on the opposite shoulders. The time in which

the participants were able to retain the

“Biering-Sorensen position” was recorded as the score.

Latimer, Maher, Refshauge, and Colaco (1999) suggested

that the Biering-Sorensen test was a reliable test to

measure back endurance which was able to identify back

health of individuals.

The V-sit Flexor Endurance Test was an alternative

to assess core muscles function (McGill, Belore, Crosby,

& Russell, 2010). The focus of this test was to measure

the endurance of the rectus abdominis and the oblique

muscles. To perform this test, the participants were

asked to hold a sit-up posture with the back lying on

a jig angled at 55 degrees from the floor. The knees

and hips of participants were flexed at 90 degrees. The

arms were crossed on the chest with the hands rested

20

on the opposite shoulders. The toes were secured under

toe straps. The test started by pulling the jig back

10 cm. The participants were asked to hold the isometric

posture for as long as possible. The score was the time

the proper position was maintained.

The Side Bridge Endurance Test was used to measure

isometric endurance of lateral flexors. This test was

development by McGill (2001). To perform the Side Bridge

Endurance Test, the participants were instructed to lie

in the full side-bridge position on the exercise mat.

Their legs are extended, with the top foot placing in

front of the lower foot for support. The body was

supported by one elbow and the feet while having the

hips off the exercise mat to form a straight line over

the body length. The free arm was held across the chest

with the hand placed on the opposite shoulder. The time

the participants were able to maintain the side bridge

position with hips and knees off the exercise mat was

recorded as the score. The reliability of Side Bridge

Endurance Test was demonstrated by Evans, Refshauge,

and Adams (2007).

The endurance of the flexors could be measured by

the Flexor Endurance Test (McGill, Belore, Crosby, &

Russell, 2010). The participants were instructed to lie

face down on the exercise mat with the body trunk

21

straight, elbows directly placed under the shoulders

and the hands together. The feet of participants were

placed close to each other to form a base. The test

administrator began the time as soon as the participants

were in the proper position and stopped the time when

the participants failed to maintain the rigid plank

position.

The Core Muscle Strength and Stability Test was

a simple field test to assess core muscle strength and

endurance (Mackenzie, 2005). This test contained a

protocol which required the participants to perform

different actions in a prescribed sequence. The test

started by having the participants in plank position

with elbows placing on the ground. The participants were

instructed to maintain this position for 60 seconds.

Then, the participants were asked to perform the

followings:

1. Lift the right arm off the ground and hold for 15

seconds

2. Return the right arm to the ground and lift the left

arm off the ground, hold for 15 seconds

3. Return the left arm to the ground and lift the right

leg off the ground, hold for 15 seconds

22

4. Return the right leg to the ground and lift the left

leg off the ground, hold for 15 seconds

5. Lift the left leg and right arm off the ground, hold

for 15 seconds

6. Return the left leg and right arm to the ground

7. Lift the right leg and left arm off the ground, hold

for 15 seconds

8. Return to the plank position and maintain the posture

for 30 seconds

The participants were regarded as having good core

muscles function if they were able to perform the whole

protocol. In this study, the Modified Plank Test was

used to examine the core muscles functions of

participants. The essence of this test came from the

Core Muscle Strength and Stability Test (Mackenzie,

2005). Participants were instructed to repeat the

sequences of the Core Muscle Strength and Stability Test

for as many as possible. Their performance was then

quantified by the time elapsed in proper forms.

23

The Role of Core Muscles in Sport-specific

Performance

The relationship between core muscles function and

sports performance was documented in several studies.

In general, most major muscles of the upper and lower

body attached with the core muscles. Strong core muscles

provided a stable platform, which allowed more powerful

and efficient movement of the limbs (Handzel, 2003).

Racket sports players or athletes who relied on other

implement to impart power required strong core muscles

to better themselves.

More specific relationship between core muscles

function and sports performance were illustrated in

numerous investigations. Abt et al. (2007) studied the

relationship between cycling mechanics and core

stability. It was suggested that although cycling was

mainly a sagittal plane activity, core muscles were

still an important physical quality to cyclists.

Strengthening core muscles could enhance the stability

of the foundation leverage from which the cyclist would

be able to produce more power.

The influence of core muscles training on

performance in female professional golfer was

investigated by Kim (2010). It was found that the female

professional golfers who receive a 12-week core muscles

24

training showed improvement in divers shot performance

while the control group did not demonstrate such changes.

These findings supported the value of core muscles

training in professional sports.

Another study outlined the relationship between

core muscles function and performance in professional,

college, high school, and youth baseball players

(Aguinaldo, Buttermore, & Chambers, 2007). It was

suggested that strong core muscles provided a basis for

powerful upper truck rotation which contributed to

better overhead throwing performance in baseball. The

performance of pitch in baseball also related to core

muscles. In the study of Stodden, Fleisig, McLean, Lyman,

and Andrews (2001), the role of trunk in pitching

performance was examined. It was found that five pelvis

and upper torso variables were associated with

variations in ball velocity among individual pitchers.

More trunk strengthening exercises were recommended to

pitchers.

The importance of core muscles function to elite

tennis players was also investigated (Ellenbecker &

Roetert, 2004). The evolution of strokes in the modern

tennis games increased the demands on trunk rotation

in elite tennis players. It was found that strong core

muscles enabled stable and powerful truck rotation

25

which was essential for elite tennis players to perform

powerful groundstroke.

A study conducted at the Indiana State University

(2009) established a relationship between core muscle

strength and performance among collegiate football

players. Those collegiate football players with better

performance in core muscles assessment, including back

extension, trunk flexion, and right and left side bridge,

performed better in the football skills tests.

However, the role of core muscles in sports

performance was not confirmed in all studies. The

relationship between core stability and performance in

football players was examined by Nesser, Huxel, Tincher,

and Okada (2008). It was found that there was no strong

relationship between core strength and football

performance variables (strength and power). The authors

suggested that improvement in core muscles function

would not contribute to better performance in football.

The significance of core muscles training was

questioned.

Tse, McManus, and Masters (2005) produced similar

results. It was revealed that participants who received

core muscles training and showed improvements in core

muscle endurance did not demonstrate improvements in

rowing-specific test (a 2000-m time trial on a rowing

26

ergometer). The relationship between training of core

muscles and improvements in physical performance tasks

in rowing was not supported.

The role of core muscles in distance running was

mentioned in different studies and sources. It was

believed that strengthening core muscles was important

for maintaining good running forms (Pierce, Murr, & Moss,

2007). For instance, strong erector spinae muscle

enabled runners to maintain the most efficient upright

running posture. For long distance runners, the

abdominals muscles were important as well. As suggested

by Bosch and Klomp (2005), the abdominals muscles

functioned as an elastic band cum a corset during running.

The abdominals muscles worked concentrically,

eccentrically, and statically so as to produce ideal

intermuscular coordination to maintain efficient

running form.

In the biomechanics aspect, strong core muscles

would also help running. Ground reaction force (GRF)

was refereed as the force exerted by the ground on the

runners (Bosch & Klomp, 2005). Research showed that

strong core muscles helped keep ground reaction forces

within an optimal range and therefore promote better

running economy (Sato & Mokha, 2009). Further, strong

core muscles improved dynamic stability of the lower

27

limbs. This helped keep vertical ground reaction forces

and horizontal ground reaction forces within an optimal

range and correspondingly maintain desirable running

efficiency.

However, the relationship between core muscles and

running performance was not firmly established. In the

study of Stanton, Reaburn, and Humphries (2004), the

male young runners who received a 6-week Swiss ball

training on core muscles did not show improvement in

neither running economy nor running posture.

Based on the studies stated above, the

relationship between core muscles function and sports

performance, especially in running performance, was not

well established. More research was needed to further

explore the importance of core muscles to running

performance.

28

Summary

The review of literature section identified

previous studies on core muscles function. Core muscles

involved several muscles in the abdominals, hip, and

back. These muscles are important to support posture,

transfer force, and coordinate muscular actions

(Handzel, 2003). Core muscles training was commonly

applied in the strength and conditioning workouts,

health and fitness activities, and rehabilitation

programs (McGill, 2001). However, there was no

consensus on the role of core muscles in sports

performance. Some studies showed relationship between

stronger core muscles and better athletic performance,

while some studies did not support such relationship.

With the increasing popularity of core muscles training,

there was a research gap to further explore the role

of core muscles in sports performance. Therefore, the

purpose of this study was to identify the relationship

between core muscles function and running performance

of Hong Kong Chinese male long distance runners. The

information provided in this study enabled the coaches

and athletes to evaluate the effectiveness of their

training programs.

29

Research Hypothesis

In this study, the following hypothesis was stated

as follows:

1. There would be a negative relationship between the

results in the Modified Plank Test and the time used

to complete the 10 km Race in the Standard Chartered

Hong Kong Marathon 2011 among Hong Kong Chinese male

long distance runners.

30

CHAPTER 3

METHODOLOGY

The aim of this study was to investigate the


performance in long distance runners. This chapter

illustrated the methodology used in the study. The

sections of this chapter included: (a) participants,

(b) research design, (c) definition of terms, (d)

procedures, (e) test protocol, (f) delimitations, (g)

assumptions, and (h) methods of analysis.

Participants

Fifty one Hong Kong Chinese male long distance

runners volunteered for this study. Their ages ranged

from 16 to 36 years. They were recruited from cross

country teams and athletic teams of secondary schools

as well as community athletic clubs. Each participant

was asked to complete a physical activity readiness

questionnaire (Appendix A) and a written informed

consent form (Appendix B) prior to data collection. The

participants were all physically active individuals

with no history of having chronic diseases. They had

no injuries at the time of data collection.

As for their running background, all participants

were regular long distance runners with more than two

years experiences in this sport. They had been

31

participated in long distance races organized by the

Hong Kong Amateur Athletic Association and other sports

organizations. They had also competed in the Standard

Chartered Hong Kong Marathon 2011 – 10 km Race which

was held on 20 February 2011.

Research Design

This study was a correlational research which aimed

at identifying the relationship between core muscles

function and performance in Hong Kong Chinese male long

distance runners.

In this study, the Modified Plank Test was adopted

to assess the core muscles function of participants.

This test was modified from the Core Muscle Strength

and Stability Test. The Core Muscle Strength and

Stability Test was developed by Mackenzie (2005). It

was a one-cycle core muscles function test. The Modified

Plank Test turned the Modified Plank Test into a repeated

cycle exercise which required the participants to

perform as many as possible.

32

Definition of Terms

In this study, the following operational

definitions were used:

Core Muscles

The core muscles referred to the muscles in the

abdomen, pelvic floor, sides of the trunk, back,

buttocks, hip, and pelvis (Fahey, Insel, & Roth, 2007,

p. 155). A total of 29 muscles were attached to the core.

Long Distance Running

Long distance running referred to the races up to

and including distances of 10000 m (Hickey, 2006, p.

53).

Procedures

Data collection of this study was conducted from

February to April 2011. All tests were conducted by the

same test administrator. Each test session accommodated

one participant. Prior to data collection, each

participant was asked to complete a physical activity

readiness questionnaire (Appendix A) and a written

informed consent form (Appendix B). They were explained

about the potential risks of taking part in this study.

Afterwards, the participants were asked about their age,

running workout (average weekly training duration and

average weekly training distance), and results in the

Standard Chartered Hong Kong Marathon 2011 – 10 km Race.

33

After answering the questions above, participants

were instructed to remove their shoes to measure body

weight and body height. The body weight of participants

was measured by a digital scale with an accuracy of +

0.1 kg. Standing height was measured to the nearest 0.1

cm with the use of a commercial stadiometer. The

participants were instructed to stand in an erect

posture with heels together and looking forward. Body

Mass Index (BMI) was calculated by dividing weight (kg)

by height (m2).

Before performing the Modified Plank Test, a

ten-minute warm up session was given to each participant.

The participants performed some low intensity movements

and stretching exercises under the supervision of the

test administrator. The main objectives of the warm up

were to increase participant’s body temperature

slightly above resting level and to reduce the chance

of injury.

Following the warm up session, the test

administrator demonstrated the sequences of the

Modified Plank Test to the participants. A practice

trial was given to each participant. Afterwards, the

participants were instructed to perform the first test

trial. The participants were asked to perform Sequence

1 through Sequence 8 of the Modified Plank Test. The

34

test administrator started counting the time once the

participants performed Sequence 1. If the participants

were able to finish Sequence 1 to Sequence 8, they would

be instructed to perform Sequence 2 to Sequence 8

repeatedly until exhaustion or failing to maintain

proper forms for 3 times. The test results were the total

time the participants getting in the sequences with

proper forms.

A 30-minute rest would be assigned after the first

test trial. The second test trial was conducted after

the rest. The procedures and arrangement were identical

to the first test trial. All test results were recorded

in the record sheet (Appendix C).

A 10-minute cool down session was arranged after

the test. The participants were asked to do some

stretching exercises. The whole test session lasted for

around 120 minutes. The participants were informed that

they were allowed to withdraw from the test with any

reasons.

Test Protocol

In this study, the Modified Plank Test was adopted

to assess the core muscles function of participants.

The origin of this test came from the Core Muscle

Strength and Stability Test, which was developed by

Mackenzie, an England athletic coach, in 2005. The Core

35

Muscle Strength and Stability Test was a one-cycle core

muscles function test. The Modified Plank Test was

applied as a repeated cycle exercise test until

exhaustion or failure of attaining prescribed criteria.

The Modified Plank Test started by asking the

participants to hold a basic prone bridge position using

toes and forearms for support. The feet were placed

shoulder width apart while the upper body rested on the

elbows and forearms. Each arm formed a 90-degree angle

(upper arm to lower arm) and kept shoulder width apart.

The shoulders, hips, and ankles formed a straight line.

The components and sequences (Sequence 1 to

Sequence 8) of the Modified Plank Test were listed as

follows (Pictorial illustration of the Modified Plank

Test was provided in Appendix D):

1. Maintain the basic plank position for 60 seconds

2. Lift the right arm and hold this position for 15

seconds

3. Resume the right arm and lift the left arm, hold this

position for 15 seconds

4. Resume the left arm and lift the right leg, hold this


5. Resume the right leg and lift the left leg; hold this


36

6. Lift the left leg and the right arm simultaneously,

hold this position for 15 seconds

7. Resume the left leg and the right arm, lift both right

leg and left arm, hold this position for 15 seconds

8. Return to the basic plank position and hold this


If the participants were able to complete Sequence

1 to Sequence 8 with proper forms, they would be

instructed to perform Sequence 2 to Sequence 8

repeatedly until they failed to attain the prescribed

criteria for 3 times or they fell on the exercise mat.

The test results were the total time the participants

getting in the sequences with proper forms.

Delimitations

The delimitations of this study were as follows:

1. Fifty one Hong Kong Chinese male long distance

runners aged from 16 to 36 years participated in this

study.

2. As for the recruitment of participants, this study

adopted the convenience sampling method.

3. The Modified Plank Test was used to examine the core

muscles function of participants.

37

4. The running background of the participants were

reflected by their average weekly training duration,

average weekly training distance, and their results

in the Standard Chartered Hong Kong Marathon 2011 –

10 km Race.

5. The study was conducted for a period of three months,

from February to April, 2011.

Assumptions

The assumptions of this study were as follows:

1. The participants understood the instructions of the

Modified Plank Test.

2. The participants performed their best in the

Modified Plank Test.

3. The participants’ self-reported results in the

Standard Chartered Hong Kong Marathon 2011 – 10 km

Race were accurate. In order to ensure accuracy,

the test administrator countered check the results

of the participants on the official website of the

Race (Standard Chartered Hong Kong Marathon, 2011).

Methods of Analysis

The data obtained in this study was entered into

the Statistical Package for Social Science (version,

16.0) (SPSS, SPSS INC., Chicago, IL, USA) file for data

analysis. The levels of significance were set at .05.

The variables included participants’ age, body weight,

38

body height, body mass index, average weekly training

duration, average weekly training distance, results in

the Standard Chartered Hong Kong Marathon 2011 – 10 km

Race, and performance in the Modified Plank Test (Two

test trials).

Pearson product-moment correlation was employed

for the relationship between the Modified Plank Test

data and 10 k race results. The coefficient of

determination was used to show the common variance

between modified plank test data and 10 k results. The

reliability of the Modified Plank Test was assessed by

the intraclass correlation coefficient. For

statistical purpose, the following null hypothesis was

stated as follows:

1. There would be no relationship between the results

in the Modified Plank Test and the time used to

complete the 10 km Race in the Standard Chartered



39

Further, the participants (N = 51) were divided into

2 groups, the Junior Group (n = 21) of 19-years-old or

below and the Senior Group (n = 30) of 20-years-old or

above. This arrangement was in line with the divisioning

mechanism suggested by the Hong Kong Amateur Athletic

Association (2011). T-test for independent groups was

conducted to compare their performance in the Modified

Plank Test and results in the Standard Chartered Hong

Kong Marathon 2011 – 10 km Race to depict the performance

of Hong Kong long distance runners.

40

CHAPTER 4

ANALYSIS OF DATA

The purpose of this study was to examine the


performance in Hong Kong Chinese male long distance

runners. This chapter presented the results of the data

analysis and the testing of hypotheses. Discussion on

the results was also included.

Results

Characteristics of the Participants

A total of 51 Hong Kong Chinese male long distance

runners participated in this study. Their physical

characteristics, running background, and results of the

Modified Plank Test were presented in Table 1. Overall,

the participants were intermediate long distance

runners, with 69% (n = 35) averaged 8 km or more per

week, and 49 % (n = 25) covered 40 km or more per week.

41

Table 1

Demographic Information of the Participants (N = 51)

Minimum Maximum M SD

Age 16.00 36.00 22.24 5.24

H (m) 1.55 1.81 1.71 0.06

W (kg) 47.63 77.11 62.65 6.79

BMI (kg / m2) 16.59 32.10 21.33 2.32

D(hr) 4.00 18.00 8.59 3.60

DS(km) 10.00 100.00 39.12 23.51

R(min) 33.20 69.90 45.15 10.22

P1 (min) 1.05 8.08 2.90 1.29

P2 (min) 1.47 9.00 3.27 1.59

Note. H = Body height; W = Body weight; BMI = Body mass

index; D = Average weekly training duration; DS = Average

weekly training distance; R = Results in the Standard

Chartered Hong Kong Marathon 2011 – 10 km Race; P1 =

Results in the first trial of the Modified Plank Test;

P2 = Results in the second trial of the Modified Plank

Test.

42

Reliability of the Modified Plank Test

The reliability of the Modified Plank Test was

examined using the intraclass correlation coefficient.

In this study, the R value of .87 demonstrated a high

reliability of the Modified Plank Test (Nunnally &

Bernstein, 1994).

Relationships among Variables

Pearson correlation coefficients were calculated

as measures of association between core muscles

function and performance of long distance runners.

Correlation among results of the Modified Plank Test,

running background, and running performance was given

in Table 2. A number of significant correlations were

shown. Age was found to have weak and positive

relationships with the two Modified Plank Rest results

(r ranged from .39 to .48, p < .01). Elder participants

tended to have better performance in the Modified Plank

Test. Further, low and a weak and negative relationship

was also reveled between age and results in the Standard

Chartered Hong Kong Marathon 2011 – 10 km Race. Elder

runners most likely had better performance in the

Standard Chartered Hong Kong Marathon 2011 – 10 km Race.

43

The two Modified Plank Test results both showed a

high negative relationship (r ranged from -.60 to -.63,

p < .01) with results in the Standard Chartered Hong

Kong Marathon 2011 – 10 km Race. The r2 values for the

first trial and second trial of the Modified Plank Test

were .36 and .40 respectively. This revealed that 36%

to 40% of the variability in the Modified Plank Test

scores was associated with 10K running performance.

Runners with better results in the Standard Chartered

Hong Kong Marathon 2011 – 10 km Race tended to have better

performance in the Modified Plank Test.

The relationships among the Modified Plank Test

scores, average weekly training duration and average

weekly training distance were found to be significant.

There were moderate positive relationships between the

first trial of the Modified Plank Test and average weekly

training duration (r = .57, p < .01), as well as average

weekly training distance (r = .58, p < .01). These

translated to the r2 values of .32 and .34 respectively,

demonstrating that 32% and 34% of variance could be

explained. High positive relationships were observed

between the second trial of the Modified Plank Test and

average weekly training duration (r = .66, p < .01),

as well as average weekly training distance (r = .65,

p < .01). The corresponding r2 values were .44 and .42,

44

meaning that 44% and 42% of variance could be explained.

These results suggested that more frequent running

training related to better performance in the Modified

Plank Test.

As expected, very high relationships were observed

between training frequency and running performance. The

relationship between results in the Standard Chartered

Hong Kong Marathon 2011 – 10 km Race and average weekly

training duration was strong and negative (r = -.84,

p < .01), with r2 value of .71, meaning that 71% of the

variability in the running performance was associated

with training duration. Similar results were found

between results in the Standard Chartered Hong Kong

Marathon 2011 – 10 km Race and average weekly training

distance. A strong and negative relationship (r = -.87,

p < .01) and r2 value of .76 were observed. This suggested

that 76% of the variability in the running performance

was associated with training distance. These results

showed that more frequent training related to better

running performance.

45

To further confirm the significance of the

correlation coefficient, degrees of freedom were

considered. In the calculation of r values for the

Modified Plank Test and variables related to running

performance, the degrees of freedom were N – 2 = 49.

By reviewing the Critical Values for the correlation

coefficient table, it was concluded that all the

correlations mentioned above were significant at

the .01 level (Miller, 2010).

46

Table 2

Summary of Intercorrelation for the Modified Plank Test

and Variables Related to Running Performance (N = 51)

1 2 3 4 5 6

1. Age - .48** .39** -.37** .12 .25

2. P1 (min) - .92** -.60** .57** .58**

3. P2 (min) - -.63** .66** .65**

4. R (min) - -.84** -.87**

5. D (hr) - .93**

6. DS(km) -

Note. P1 = Results in the first trial of the Modified

Plank Test; P2 = Results in the second trial of the

Modified Plank Test; R = Results in the Standard

Chartered Hong Kong Marathon 2011 – 10 km Race; D =

Average weekly training duration; DS = Average weekly

training distance.

*p < .05. **p < .01.

47

Further, two scatter plots in Figure 1 and 2 were

given to further illustrate the relationship between

core muscles function (results of the Modified Plank

Test) and running performance (results of the Standard

Chartered Hong Kong Marathon 2011 – 10 km Race) of

participants.

Figure 1. Scatter plot for results in the Standard

Chartered Hong Kong Marathon 2011 – 10 km Race and

results in the first trial of the Modified Plank Test

(N = 51). R = Results in the Standard Chartered Hong

Kong Marathon 2011 – 10 km Race; P1 = Results in the

first trial of the Modified Plank Test.

48

Figure 2. Scatter plot for results in the Standard

Chartered Hong Kong Marathon 2011 – 10 km Race and

results in the second trial of the Modified Plank Test

(N = 51). R = Results in the Standard Chartered Hong

Kong Marathon 2011 – 10 km Race; P2 = Results in the

seond trial of the Modified Plank Test.

49

Group Difference Analysis

A series of independent sample t tests were

conducted to determine the differences between the

Junior Group (n = 21, age ranged from 16 to 19 years-old)

and the Senior Group (n = 30, age ranged from 20 to 36

years-old). The rationale of grouping followed the

divisioning mechanism suggested by the Hong Kong

Amateur Athletic Association (2011). The comparison

between the Junior Group and the Senior Group was

presented in Table 3. Significant difference was

observed in the Modified Plank Test results between the

Junior Group and the Senior Group, with t values of -2.71

(df = 49, p < .01) and -2.07 (df = 49, p < .05) for the

first and second trials respectively. Figure 3 depicted

the differences between the two groups in the Modified

Plank Test.

50

Table 3

Comparison between the Junior Group (n = 21) and the

Senior Group (n = 30)

Junior Group Senior Group

M (SD) M (SD) t

Age 17.48 (1.21) 25.57 (4.30) -8.38**

H (m) 1.69 (0.06) 1.73 (0.05) -2.12*

W (kg) 58.49 (6.55) 65.56 (5.35) -4.23**

BMI (kg / m2) 20.33 (1.70) 22.03 (2.46) -2.74**

D (hr) 8.48 (4.13) 8.67 (3.25) -0.18

DS (km) 35.48 (24.59) 41.67 (22.79) -0.92

R (min) 48.00 (10.23) 43.16 (9.89) 1.70

P1 (min) 2.35 (1.07) 3.29 (1.30) -2.71**

P2 (min) 2.74 (1.26) 3.64 (1.70) -2.07*

Note. H = Body height; W = Body weight; BMI = Body mass

index; D = Average weekly training duration; DS = Average

weekly training distance; R = Results in the Standard

Chartered Hong Kong Marathon 2011 – 10 km Race; P1 =

Results in the first trial of the Modified Plank Test;

P2 = Results in the second trial of the Modified Plank

Test.

*p < .05. **p < .01.

51

Figure 3. Modified Plank Test results (min) for the

Junior Group and the Senior Group. P1 = Results in the

first trial of the Modified Plank Test; P2 = Results

in the second trial of the Modified Plank Test.

0.000.501.001.502.00

2.503.003.504.00

P1 P2

JuniorSenior

52

Analysis to Research Hypothesis

The results of this study supported the

hypothesized relationship between core muscles

function and performance in Hong Kong Chinese male long

distance runners. This section showed the results with

respect to the research hypothesis:

1. There would be a negative relationship between the

results in the Modified Plank Test and the time used

to complete the 10 km Race in the Standard Chartered



In this study, a high and negative relationship was

found between the results in the first trial and the

second trial of the Modified Plank Test and the time

used to complete the 10 km Race in the Standard Chartered

Hong Kong Marathon 2011. Therefore, hypothesis one was

substantiated.

53

Discussion

The purpose of this study was to identify the

relationship between core muscles function and running


runners. It appeared that the relationship was

established. This study suggested that long distance

runners with better core muscles function most likely

had better performance in 10 km race.

Similar findings were reported in previous studies.

Core muscles training was shown to improve 5000 m running

performance in runners (Sato & Mokha 2009). Running

involved a series of unilateral hip flexion and

extension movements which placed considerable

destabilizing torques on the trunk (Schache, Bennell,

Blanch, & Wrigley, 1999). Ferber (2010) suggested that

core muscles training was common to runners. Sufficient

core muscles training contributed to a positive effect

to running performance. Behm, Cappa, and Power (2009)

stressed that strong core musculature help runners

attaining optimal performance and maintaining

musculoskeletal trunk health.

The relationship between core muscles function and

sport performance found in this study was in line with

previous studies. Roetert (2001) suggested that core

muscles function was essential for good performance in

54

almost all sports. Strong hip and truck muscles assisted

the athletes to produce better sporting movements.

Kibler, Press, and Sciascia (2006) commended that core

muscles group as a pivotal part in normal three-planar

motions which were common in most sports activities.

Stronger core muscles provided a basis for greater force

production in the upper and lower body (McCurdy,

Langford, Doscher, Wiley, & Mallard, 2005; Willardson,

2007). McGill (2010) also supported the role of strong

core muscles in maximizing sports performance.

Specifically, core muscles were important to different

athletic performances such as pitching speed and

accuracy (Marsh, Richard, Williams, & Lynch, 2004),

golf club head speed (Thompson, Cobb, & Blackwell, 2007),

and tennis (Ellenbecker & Roetert, 2004).

The results of this study on the correlation between

core muscles function and performance in long distance

runners were promising. The findings confirmed the role

of core muscles in long distance running. This provided

more evidence to support the existence of core muscles

training in runners’ workouts.

Besides the relationship core muscles function and

55

running performance, the results obtained in this study

also supported the relationship between training

frequency and running performance. Frequency and

duration of running were the key factors to running

performance (Pierce, Murr, Moss, 2007). Despite

muscular strength and endurance training on the core

muscles group, well planned running drills were also

essential for good running performance.

Group difference in the Modified Plank Test was

observed in this study. Elder participants tend to

performed better than their younger counterparts in the

Modified Plank Test. The difference in level of maturity

might explain this age difference.

Besides, such difference might be explained by the

less emphasis on core muscles training for young runners.

In this study, the participants of the Junior Group were

mainly members of the athletics teams and cross country

teams in secondary schools. In Hong Kong, the focus of

running training in secondary schools lied on running

frequency and duration. The supplement of muscular

strength and endurance training was not emphasized.

According to the findings of this study, it was advised

that more core exercises could be arranged for junior

runners. This study outlined the relationships among

age, training, and running performance. Other studies

56

were recommended to further explore the causal

relationships among theses variables.

Based on the results of this study, it was found

that the Modified Plank Test was a reliable assessment

tool to examine core muscles function. The Modified

Plank Test originated from the Core Muscle Strength and

Stability Test which was developed by Mackenzie (2005).

The Modified Plank Test turned a single-cycle Core

Muscle Strength and Stability Test into a repeated

exercise test. In the Modified Plank Test, the

participants were instructed to perform as many

sequences as possible with proper forms. The score was

the time in which the participants performed proper

sequences and forms. The Modified Plank Test was easy

to administer which only required an exercise mat,

stopwatch, and limited testing space. Based on the

reliability results found in this study, it was valuable

to further investigate the validity of Modified Plank

Test to confirm the application of this test to examine

individual core muscles function.

57

Limitations

This study provided a clearer picture about the



runners. However, some limitations in this study were

identified as follows:

1. The adoption of convenience sampling method

necessitated caution in the generalization of data

to a larger population.

2. The test performance of participants in the Modified

Plank Test might be affected by other reasons such

as their motivation, emotional status, or attention

span.

3. The results of this study were limited to the

validity and reliability of the Modified Plank Test.

58

CHAPTER 5

SUMMARY AND CONCLUSIONS

Summary

Many long distance runners regarded core muscles

training as a part of their training modules. Numerous

core endurance and strength exercises were introduced

in different health, fitness, and sports settings. This

study attempted to identify the relationship between

core muscles function and performance in Hong Kong

Chinese male long distance runners. To this end, a total

of 51 long distance runners participated in this study.

The training schedules and running performance of

participants were recorded. All participants performed

the Modified Plank Test to examine their core muscles

function. The data for this study was collected from

February to April 2011.

The data analysis showed the following major

findings:

1. The Modified Plank Test results related to the

results in the Standard Chartered Hong Kong Marathon

2011 – 10 km Race.

2. Group differences in the Modified Plank Test results

were found.

3. The Modified Plank Test demonstrated high

reliability.

59

Conclusions

Findings of this study depicted the relationship

between core muscles function and performance in long

distance running. The following conclusions were

warranted in this study:

1. Male long distance runners with stronger core muscles

most likely had better performance in 10 k race.

2. Elder runners demonstrated better core muscles

function than younger runners.

3. The Modified plank Test was a reliable tool to examine

core muscles function.

Recommendations for Further Study

The following recommendations were made for

further research in the aspect of core muscles function:

1. The sample of this study was limited to male long

distance runners. The results of this study might

not be able to illustrate the relationship between

core function and performance in female runners due

to anatomical and physiological differences.

Therefore, this study could be replicated using both

male and female participants.

60

2. The core muscles function was assessed solely by the

Modified Plank Test in this study. Due to the

multi-facets of core muscles, more assessments were

recommended to evaluate participants’ core muscles

function in future study.

3. Another investigation could be conducted to examine

the causal relationship between core muscles

function and running performance.

61

REFERENCES

Abt, J. P., Smoliga, J. M., Brick, M. J., Jolly, J. T.,

Lephart, S. M., & Fu, F. H. (2007). Relationship

between cycling mechanics and core stability.

Journal of Strength and Conditioning Research,

21(4), 1300-1304.

Aguinaldo, A. L., Buttermore, J., & Chambers, H. (2007).

Effects of upper trunk rotation on shoulder joint

torque among baseball pitchers of various levels.

Journal of Applied Biomechanics, 23(1), 42-51.

American College of Sports Medicine (2010). ACSM's

guidelines for exercise testing and prescription.

Philadelphia, PA: Wolters Kluwer Health.

Behm, D. G., Cappa, D., & Power, G. A. (2009). Trunk

muscle activation during moderate- and

high-intensity running. Applied Physiology,

Nutrition & Metabolism, 34(6), 1008-1010.

Biering-Sorenson, F. (1984). Physical measurements as

risk indicators for low back trouble over a one year

period. Spine, 9(2), 106-109.

Bosch, F., & Klomp, R. (2005). Running: biomechanics

and exercise physiology in practice. New York, NY:

Elsevier Churchill Livingstone.

62

Canadian Society for Exercise Physiology (2002). The

Physical Activity Readiness Questionnaire.

Retrieved 25 January, 2011, from

http://www.csep.ca/cmfiles/publications/parq/pa

r-q.pdf

Carter, J. M., Beam, W. C., McMahan, S. G., Barr, M.

L., & Brown, L. E. (2006). The effects of stability

ball training on spinal stability in sedentary

individuals. Journal of Strength and Conditioning

Research, 20(2), 429-435.

Cowley, P. M., Swensen, T. C. (2008). Development and

reliability of two core stability field tests.


22(2), 619-624.

Ellenbecker, T. S., & Roetert, E. P. (2004). An

isokinetic profile of trunk rotation strength in

elite tennis players. Medicine & Science in Sports

& Exercise, 36(11), 1959-1963.

Evans, K., Refshauge, K., & Adams, R. (2007). Trunk

muscle endurance tests: reliability, and

comparison of holding times between male and female

athletes. Journal of Science & Medicine in Sport,

10(6), 447-455. doi: 10.1016/j.jsams.2006.09.003

63

Fahey, T. D., Insel, P. M., & Roth, W. T. (2007). Fit

and well (7th ed.). Hoboken, NJ: J. Wiley.

Ferber, R. (2010). The importance of core stability to

prevent and treat running injuries. Retrieved from

http://www.provincialfitnessunit.ca/media/uploa

ds/Importance_of_Core_Stability-1.pdf

Handzel, T. M. (2003). Core training for improved

performance. NSCA's Performance Training Journal,

2(6), 26-30.

Hibbs, A. E., Thompson, K. G., French, D., Wrigley, A.,

& Spears, I. (2008). Optimizing performance by

improving core stability and core strength. Sports

Medicine, 38(12), 995-1008.

Hickey, J. (2006). Understanding athletics. Leeds,

England: Coachwise.

Hong Kong Amateur Athletic Association (2011). About

Hong Kong ranking and Hong Kong records. Retrieved

from

http://www.hkaaa.com/page.php?pid=112&mid=151&l

ang=eng

Indiana State University (2009). To the core of core

training. Journal of Pure Power, 4(2), 29-31.

Kibler, W. B., Press, J., & Sciascia, A. (2006). The

role of core stability in athletic function. Sports

Medicine, 36(3), 189-198.

64

Kim, K. J. (2010). Effects of core muscle strengthening

training on flexibility, muscular strength.

International Journal of Applied Sports Sciences,

22(1), 111-127.

Latimer, J., Maher, C. G., Refshauge, K., & Colaco, I.

(1999). The reliability and validity of the

Biering-Sorensen test in asymptomatic subjects and

subjects reporting current or previous nonspecific

low back pain. Spine, 24(20), 2085-2089.

Mackenzie, B. (2005). Core muscle strength & stability

test. Retrieved 30 October, 2010, from

http://sportsmedicine.about.com/od/bestabexerci

ses/a/core_test.htm

Marieb, E. N. (1998). Human anatomy & physiology (4th

ed.). Menlo Park, CA: Benjamin/Cummings.

Marsh, D.W., Richard, L.A., Williams, L.A., & Lynch,

K.J. (2004). The relationship between balance and

pitching error in college baseball pitchers.


18(3), 441-446.

65

McCurdy, K. W., Langford, G. A., Doscher, M. W., Wiley,

L. P., & Mallard, K. G. (2005). The effects of

short-term unilateral and bilateral lower-body

resistance training on measures of strength and

power. Journal of Strength and Conditioning

Research, 19(1), 9-15.

McGill, S. (2010). Core training: evidence translating

to better performance and injury prevention.

Strength & Conditioning Journal, 32(3), 33-46.

McGill, S., Belore, M., Crosby, I., & Russell, C. (2010).

Clinical tools to quantify torso flexion endurance:

normative data from student and firefighter

populations. Occupational Ergonomics, 9(1), 55-61.

doi: 10.3233/OER-2010-0181

McGill, S. M. (1995). The mechanics of torso flexion:

situps and standing dynamic flexion manoeuvres.

Clinical Biomechanics, 10(4), 184-92. doi:

10.1016/0268-0033(95)91396-V

McGill, S. M. (2001). Lower back stability: from formal

description to issues for performance and

rehabilitation. Exercise and Sport Science Reviews,

29(1), 26-31. doi:

10.1097/00003677-200101000-00006

66

Miller, D. K. Measurement by the physical educator: why

and how (6th ed.). New York, NY: McGraw-Hill.

Nesser, T. W., Huxel, K. C., Tincher, J. L., & Okada,

T. (2008). The relationship between core stability

and performance in division I football players.


22(6), 1750-1754.

Nunnally, J., & Bernstein, I. (1994). Psychometric

Theory New York (3rd ed.). New York, NY: McGraw.

Olmsted, L. C., Carcia, C. R., Hertel, J., & Shultz,

S. J. (2002). Efficacy of the Star Excursion Balance

Tests in detecting reach deficits in subjects with

chronic ankle instability. Journal of Athletic

Training, 37(4), 501-506.

Pierce, B., Murr, S., & Moss, R. (2007). Run less, run

faster: become a faster, stronger runner with the

revolutionary first training program. Emmaus, PA:

Rodale.

Pollock, M. L., Wilmore, J. H., & Fox, S. M. (1978).

Health and fitness through physical activity. New

York, NY: Wiley.

67

Reid, D., & Mcnair, P. (2000). Factors contributing to

low back pain in rowers. British Journal of Sports

Medicine, 34(5), 321-322. doi:

10.1136/bjsm.34.5.321

Richardson, C. A., Snijders, C. J., Hides, J. A., Damen,

L., Pas, M. S., & Storm, J. (2002). The relation

between the transversus abdominis muscles,

sacroiliac joint mechanics, and low back pain.

Spine, 27(4), 399-405.

Roetert, P. E. (2001). 3D balance and core stability.

In B, Foran B (Eds.), High-performance sports

conditioning: modern training for ultimate

athletic development (pp.119-138). Champaign, IL:

Human Kinetics.

Sato, K., & Mokha, M. (2009). Does core strength training

influence running kinetics, lower-extremity

stability, and 5000-M performance in runners?


23(1), 133-140.

Schache, A. G., Bennell, K. L., Blanch, P. D., & Wrigley,

T. V. (1999). The coordinated movement of the

lumbo-pelvic-hip complex during running: a

literature review. Gait Posture, 10(1), 30-47.doi:

10.1016/S0966-6362(99)00025-9

68

Standard Chartered Hong Kong Marathon 2011 (2011).

Standard Chartered Hong Kong Marathon 2011:

official results. Retrieved 1 April, 2011, from

http://www.hkmarathon.com/marathon/eng/event/re

sults/2011/default.jsp

Stanton. R, Reaburn, P. R., & Humphries, B. (2004). The

effect of short-term Swiss ball training on core

stability and running economy. Journal of Strength

and Conditioning Research, 18(3), 522-528.

Stodden, D. F., Fleisig, G. S., McLean, S. P., Lyman,

S. L., & Andrews, J. R. (2001). Relationship of

pelvis and upper torso kinematics to pitched

baseball velocity. Journal of Applied Biomechanics,

17(2):164-172.

Thompson, C.J., Cobb, K.M., & Blackwell, (2007).

Functional training improves club head speed and

functional fitness in older golfers. Journal of

Strength and Conditioning Research, 21(1),

131-137.

Tortora. G. J. (2005). Principles of human anatomy (10th

ed.). Hoboken, NJ: J. Wiley.

69

Tse, M. A., McManus, A. M., & Masters, R. S. W. (2005).

Development and validation of a core endurance

intervention program: implications for

performance in college-age rowers. Journal of

Strength and Conditioning Research, 19(3),

547-552.

Whittaker, J. L. (2004). Abdominal ultrasound imaging

of pelvic floor muscle function in individuals with

low back pain. Journal of Manual and Manipulative

Therapy, 12(1), 44-49.

Willardson, J. M. (2007). National Strength and

Conditioning Association hot topic series:

unstable resistance exercises. Retrieved 1 April,

2011, from

http://www.nsca-lift.org/HotTopic/download/Unst

able%20Resistance%20Exercises.pdf

Willson, J. D., Dougherty, C. P., Ireland, M. L., & Davis,

I. M. (2005). Core stability and its relationship

to lower extremity function and injury. Journal of

the American Academy of Orthopaedic Surgeons, 13(5),

316-325.

70

APPENDIX A

Physical Activity Readiness Questionnaire (PAR-Q)

Source: Public Health Agency of Canada and the Canadian

Society for Exercise Physiology (2002)

71

APPENDIX B

Written Informed Consent Form

Purpose and Explanation of the Test You will perform the Modified Plank Test on the exercise

mat. The aim of the Modified Plank Test is to assess

your core muscles function. The Modified Plank Test

started by asking you to hold a basic prone bridge

position using toes and forearms for support.

The components and sequences (Sequence 1 to Sequence

8) of the Modified Plank Test were listed as follows:

1. Maintain the basic plank position for 60 seconds

2. Lift the right arm and hold this position for 15

seconds

3. Resume the right arm and lift the left arm, hold this


4. Resume the left arm and lift the right leg, hold this


5. Resume the right leg and lift the left leg; hold this


6. Lift the left leg and the right arm simultaneously,


7. Resume the left leg and the right arm, lift both right

leg and left arm, hold this position for 15 seconds

8. Return to the basic plank position and hold this


72

If you are able to complete Sequence 1 to Sequence 8

with proper forms, you would perform Sequence 2 to

Sequence 8 repeatedly until you fail to attain the

prescribed criteria for 3 times or you fell on the

exercise mat.

Attendant Risks and Discomforts

During the tests, certain changes may occur. These

changes include abnormal blood pressure responses,

fainting, irregularities in heart beat, and heart

attack. Every effort is made to minimize these

occurrences. Emergency equipment and trained personnel

are available to deal with these situations if they

occur.

Benefits to be expected from the Test

The tests allow us to examine your core muscles function

and to assess your physical fitness status. The results

are used to prescribe a safe, sound exercise program

for you. Records are kept strictly confidential unless

you consent to release this information.

Inquiries

Any questions about the test procedures and the results

of your test are encouraged. If you have any questions

or concerns, please ask the test administrator to

explain further.

73

Freedom of Consent

I hereby consent to voluntarily engage in the Modified

Plank Test to determine my core muscles function. My

permission to perform this test is given voluntarily.

I understand I am free to stop the test at any point

if I so desire.

I have read this form, and I understand the test

procedures that I will perform and the attendant risks

and discomfort. Knowing these risks and discomforts,

and having an opportunity to ask questions that have

been answered to my satisfaction, I consent to

participate in this test.

Date:

Signature of

Participant:

Date:

Signature of

Witness:

Source: modified from American College of Sports

Medicine (2010, p. 56-57)

74

APPENDIX C

Record Sheet

Participant ID: __________

Test Date: (yy) (mm) (dd)

Background information

Name:

Date of Birth: (yy) (mm) (dd)

Height: m

Weight: kg

BMI: kg / m2

Running background and performance

Average weekly training distance: hr

Average weekly training distance: km

Results in the Standard Chartered

Hong Kong Marathon 2011 – 10 km Race: min

Performance in the Modified Plank Test

First trial: min

Second trial: min

75

APPENDIX D

Pictorial Illustration of the Modified Plank Test

Sequence Description

1 Maintain the basic plank position for 60

seconds

2 Lift the right arm and hold this position

for 15 seconds

3 Resume the right arm and lift the left arm,


76


4 Resume the left arm and lift the right leg,


5 Resume the right leg and lift the left leg;


6 Lift the left leg and the right arm

simultaneously, hold this position for 15

seconds

77


7 Resume the left leg and the right arm, lift

both right leg and left arm, hold this


8 Return to the basic plank position and hold

this position for 30 seconds

78

CURRICULUM VITAE

Biographical items on the author of the dissertation,

Mr. Gi Ka Man:

1) Studied the Sport and Recreation Studies, Associate

Degree Program, from 2006 to 2008 at Hong Kong Baptist

University.

2) Studied the Physical Education and Recreation

management Program, Bachelor of Arts (Honours), at

Hong Kong Baptist University from 2006 to present.

April 2011

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