Three dimennsional analysis of peak velocity on diffrence...

THREE DIMENNS10NAL ANALYSIS OF PEAK VELOCITY

ON DIFFRENCE IIEIGHT GOLFER

-2 NOV 2001

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MASTER OF SCIENCESPORTS- SCmNCE ( BIOMECHAMCS )

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. -2001LSBN, .'974.A4-0597-5

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Thesis

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呻 E DIMENSIONAL ANALYSIS OF PEAK HAND VELOCITY

ON DIFFERENCE T{EIGHT GOLFER

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Si^i"tr l*1rr""rwiAssoc. Prof Sirirat Hirunrat, Ph.D.Major-Advisor

?!:n(7-4.u1Assoc. Prof. Thyo, Ct.or* "r,rndCo-advisor

Lect. Suwat Sidthilaw, Ph.D.Co-advisor

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Prof.Liangchai LimlomwongsePh.D.DeanFaculty of Graduate Studies

Asst. Prof. Panya Kaimuk, M.D.Board of Orthopedic SugeryChairMaster of Science Programmsin Sport ScienceCollege.of Sport Science andTechnology

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Thesis

entitled

THREE DIMENSIONAL ANALYSIS OF PEAK HAND VELOCITY

ON DIFFERENCE FIEIGHT GOLFER

was submitted to the Faculty of Graduate Studies, Mahidol university

for the degree of Master of Science (Sport Science)

on

28 August 2001

孟‖れ品倉・ネツCandidate

g^i/ l4;'*,*'Assoc. Prof. Sirirat Hirunrat, Ph.D.Chair

7U*k-?b*Assoc. Prof Thyon Chentanez, pld.Member

0t JitueLect. Suwat Sidthilaw, Ph.D.Member

.%m...K*L,**^-FAssoc. Prof. Charoen KrabuanratMember

Prof.Liangchai LimlomwongsePh.D.Dean

Faculty of Graduate StudiesMahidol University

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滅ル.DAsst. Prof Panya Kaimulq M.D.Board of Orthopedic SugeryDirectorCollege of Sport Science andTechnologyMahidol University


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ACKNOWLEDGMENT

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This study could not have been successfully completed without the assistance

of many people. First of all, I would like to express my deepest appreciation and sincere

gratitude to my advisor, Associated professor Dr. Sirirat Hirunrat for her considerable

guidance, invaluable advice, supervision and encouragement throughout the study. I am

equally grateful to Asst. professor Dr. Thyon Chentanez and Dr. Suwat Sidthilaw my

Co-advisor for their constructive comments, supervision and encouragement. They

were never lacking in kindness and support that had enables me to carry on the thesis

successfully.

I am very grateful to the thesis committee, Associated. Professor. Chalearn

Kabuanrat for suggestion and correction of the thesis.

Special tanks are given to my family and friends of master's degree at College

of Sport Science and Technology, Mahidol University No 41, for their love and

encouragement that have inspired me to reach this study.

Pronthep Rachnavy


Fac.of Grad.Studies, MahidolモJniv. Thesis/1V

4138461 SPSS/M I MAJOR:SPORT SCIENCE:M.Sc.(BIOMECHANICS)KEY WORDSI :THREE― DIMENSIONAL/PEAK HAND VELOCITY

PORNTHEP RACHNAVY:THREE DINIENSION ANALYSIS OF PEAKHAND VELOCITY ON DIFFERENCE HEIGHT GOLFER.THESIS ADVISORS:SIRIRAT HIRUNRAT,Ph.D。 , THYON CHENTANEZ、 Ph.D SUWATSIDTHILAW,Ph.D.84P.ISBN 974-04-0597-5

The positiOn at address has been found tO play an inlportant rolc in golf s、 ving.

Interest in biomechanics ofperbrmancc has lead illcreasely to the exanlillation ofjoint

angles at the addrcss position influence on peak hand velocity.

Thc purpose of this investigation was to,onlpare mcan peak hand velocity;

jdnt angles ofanHes,bces,Hps and shOdders at thc addrcss position bet、 vecn golた r

using sand wedge and iron No 3 clubso Compa五 sons were made ofthcjoint angles of

ankles, knces, hips and shoulders of short and taH 3olfers at the address pOSition.

Twenty males with single golf handicaps(10 Werc short and 10 werc tall)Werc

videotaped and analyzed using three― dilnensional techniques.

The results showed that (l) There was no significant differcnces in pcak handvelocity betn'een sancl rvedge and iron No 3 clubs. (2) The joint angles of ankles.knees, hips and shoulders at the address position with sand rvedge were significantlylower than with an iron No 3. (3) There was no significant difference in joint angles ofLnkles, knees, hips and shoulders at the address po.sition betrveen short and tall golfers.

The finding of this study woulddo not influence peak hand velocity.

suggest thatjoint angics at the address


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CONTENTS

ACKNOWLEDGMENT

ABSTRACT

LIST OF TABLES

LIST OF FIGURES

LIST OF ABBREVIATIONS

CHAPTER

I INTRODUCTION

Purposes ofthe Study

Genera1 0tteCtiVes

Specinc Ottectives

Hypotheses ofthe Study

Parameters ofthe Study

Scope ofthe Study

Ⅱ LITERATURE REVIEW

l.Background

l.l Basic Technique

l l l Address

ll.1 l Grip

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ll.13.AmCopyright by Mahidol University

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CONTENTS (CONT.)

1.1.1.4. Stance '

1. 1. 1.5. Posture

1.1.2 Backswing

1.1.3 Downswing

l. 1.4 Follow Through

1.2 Factors Influencing Displacement

1.2.1 The carry

1.2.2 Speed ofRelease!

L2.3 Direction of Release

1.2.4 Height of Release

1.2.5 AtrResistance

1.2.6 The run

1.3 Factors influencing speed

1.4 Factors influencing direction

1.5 Factors influencing distance

1 6 The CIub

The Biomechanics of Human Skeletal Muscle

2.1 Lenglh Tension Relationships

2.2 The Biomechnics of the Human Upper Extremity

2.2.1 Structure of the Shoulders

2.2.2Movements of the Shoulder Complex

VII

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CONTENTS(CONT.)

2.3 TheBiomechanics of the Human Lower Extremity

2.3.1 Structure of the Hip

2.3.2 Movements at the Hip

2.3.3 Structure of the Knee

2.3.4 Movements at the Knee

2.3.5 Structure of the Ankle

2.3.6 Movement at the Ankle

METHODS

Subject

Instrumentation

Collecting Data

AnalyzeData

Data Collection

Data Reduction and Analysis

Statistical Analysis

Experimental Protocol

RESULTS

1. The General Physical Characteristics and Physical Fitness

Characteristic

1. I General Physical Characteristics

1. 2 Physical Fitness Characteristic

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CONTENTS(CONT。 )

2 Companson ofPeak Hand Velocity of Short and

Tall Group duHng Swlng with Sand Wedge and lron No 3

3.Comparison ofthe Joint Angles ofШ es,Knees,

Hips and Shoulder at Address Position between Sand

Wedge and lron No.3 of Short and Tall Group

4.Compa五 son ofthe Joint Angles ofAnkles,Knees,

Hips and Shoulder at Address Position between Shorti

and Tall Group ofSand Wedge and lron No 3

V DISCUSSION

Companson ofAngles between Sand Wedge and lron No.3

CompaHson ofAngles between Short and Tall Group

CompaHson ofPeak Hand Velocity

Limitation

Future Research

Ⅵ CONCLUSION

REFFERENCE

APPENDⅨ ‐ .

BBLIOGRAPIIY

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LIST OF TABLE

Table

1. The United state golf association standard clubs

2. Major muscle of the shoulder

3. Major muscle of the hip

4. Major muscle of the knee

5. Major muscle of the ankle and foot

6. Anthroppometric data: age, height and weight

7. Body segment and physical characteristic data: arm, trunk, upper leg,

flexibility and hand grip.

8. Peak hand velocity between sand wedge and iron No 3 in the group

9. Comparison of ankle angle, knee angle, hip angle and shoulder angle

between sand wedge and iron No 3 in short group


between sand wedge and iron No 3 in tall group


at address position by using sand wedge between short and tall group

L2. Comparison of ankle angle, knee angle, hip angle and shoulder angle

at address position by using iron No. 3 between short and tall group

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LIST OF FIGURE

Figure

l.The golf swlng

2.Basic factor in a golf

3.A ill set of 14 clubs

4 Camera position

5 Joint angles

6.Average peak hand velocity ofsand wedge in short group

7.Average peak hand velocity ofsand wedge in tall group

8 Average peak hand velocity ofsand wedge in short group and tali group

9.CompaHson ofpeak hand velocity between sand wedge and iron No 3

in short group

10.Average peak hand velocity ofiron No 3 in short group

ll Average peak hand velocity ofiron No 3 in tali grOup

12 Average peak hand velocity ofiron No 3 in short group and tall group

13 Companson ofpeak hand velocity between sand wedge and iron No 3

in tan group.

14. Joint angles ofattes angle,knee angle,hip angle and shoulder

angle at address position ofsand wedge in short group and tall group

15. Joint angles ofankles angle,knee angle,hip angle and shoulder

angle at address position ofiron No.3 in short grOup and tall group

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LrsT oF FTGURE (CONT.)

Figure page

16. Joint angles of ankles angle, knee angle, hip angle and shoulder 6g

angle at address position by using sand wedge in short group and

tallgroup

17. Joint angles of ankles angle, knee angle, hip angle and shoulder 70

angle at address position by using iron No. 3 in short group and

tall group

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XⅡI

LIST OF ABBREVIATIONS

f1/sec = foot per second

g = gram

mph = mile per hour

NS : no significant difference

S : significance difference

SEM = standard error mean

? USGA = United state golf association

vs : versus

W : watt


Fac of Grad.Studes,Ⅳ Lhdol Univ. M.Sc.(Sport Science) / I

CHAPTER I

INTRODUCTION

The objective of the game of golf is to hit a small hard ball - the golf ball - as

few times as is necessary for it to travel from its starting point, a tee, into the located on

each green The golf ball is strucked with club designated as woods or irons. Each

player must hit his or her own stationary ball in the desired direction and for the desired

distance, using one of a variety of clubs of assorted lengths and shapes (r).

The fundamental skill in the game of golf is swinging the club. A successful

swing depends on the performance of complex sequential action involving the feet and

knees, rotation of the hips, trunk and shoulders, and movement of the arm, wrists, and

hand (2). Finally, the action occurs between the arms segment and the club. The end

result is large increase in velocity and maximum linear and angular club head speed

through impact.

Peak hand velocity, maximum speed of hand during downswing, is the ability

of golfers to generate force before transfer to the club. To achieve success in peak hand

velocity, it is desirable more relationships in the complex sequences action of the swing.

Starting from the top of the golfer's backswing, the downswing begins with weight

transfer from the right foot to the left foot (right hand golfer) turn the hips and

shoulders and the hand rotation around the body before the force was transfer to the

club.

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Pornthep Rachnavy Introduction i 2

Golfswing demands a turning or rotation of the body and free swing of the arm

and hand, and for a good posture is essential. The position of the body as the golfers

address the ball is very important. It is probably apparent that the degree of bent the

joints are related to the length of the club golfers are using. Brennan (3) has studied the

joint angles (ankles, knees, hips, shoulders, elbow) in a small group of professional

golfer during address with pitching wedge, driver and 5 iron. He found difference of all

joint angles. It is important to determine if this different remain occur between sand

wedge and iron No 3. Moreover, to determine if the joint angles between short golfers

and tall golfers at address with the same iron were difference. The difference of joint

angles during address may be incrdase or decrease peak hand velocity. During address,

, golfers flex their joint that it causes the muscle around the joint change it length

In theory, The amount of maximum isometric tension a muscle is capable of

producing is partly dependent on the muscle's length. In single muscle fibers and

isolated muscle preparations, force generation is at its peak when the muscle is at

normal resting length (neither stretched nor contracted). When the length of the muscle

increases or decreases beyond resting length, the maximum force the muscle can

produce decreases, following the form of a bell-shaped curve(4).

Within the human body, however, force generation capability increases when

the muscle is slightly stretched. Parallel-fibered muscles produce maximum tensions at

just over resting length, and pennate-fibered muscles generate maximum tensions at

between l20o and l3OYo of resting length (5). This phenomenon is due to the

contribution of the elastic components of muscle, which add to the tension present in

the muscle when the muscle is stretched. Research indicates that following eccentricCopyright by Mahidol University

Fac of Grad Studies,Mahidol Univ M.Sc.(Sport Science) / 3

exercise there may be a slight, transient increase in muscle length that impairs force

development when joint angle does not place the muscle in sufficient stretch (6).

Base on the theories, it was expected that an optimal velocity for maximal

power output would exist, and that substantially faster or slower velocities would have

less power production This phenomenon was examine in the present investigation. It

has been established that there is reason to believe that the musculature about the

ankles, knees hips and shoulders joint could be directly related to the peak hand

velocity in golf swing.

To date, however, no data are available concerning the peak hand velocity

during golfing. The present study, therefore, it is of interest to study the peak hand

velocity that occur during downswing between sand wedge and iron No 3 in short

golfers and tall golfers. It was also expected that the data obtained would serve as

baseline data for monitoring the optimal technique for the golfers.


Pornthep Rachnavy Introduction/4

Purposes of the Study

l.General Objectives

To compare the joint angles of ankles, knees, hips, and shoulders of

golfer at address position between using sand wedge and iron No 3.

2.Specific Objectives

I To compare peak hand velocity between sand wedge and iron No 3.

2 To compare the joint angles of ankles, knees, hips and shoulders of

golfer at address position between short golfer and tall golfer.

Hypotheses of the Study

1 There'are statistical significantly difference in joint angles between using sand

wedge and iron No 3.

2 There are statistical significantly difference in peak hand velocity between

using sand wedge and iron No 3.

3 There are not statistical significantly difference in the above joint angles

between short and tall golfer.

Parameters of the Study

I Joint angle of ankles, knees, hips and shoulders at address position between

sand wedge and iron No 3.

2Peak hand velocity between sand wedge and iron No 3.

3 Joint angle of ankles, knees, hips and shoulders at address position between

short golfer and tall golfer. Copyright by Mahidol University

Fac.of Grad.Stuttcs,Mahidol Univ M.Sc.(Sport Science) / 5

Scope of the Study

This study investigated the joint angles at address position between sand

wedge and iron No 3, peak hand velocity between sand wedge and iron No 3 and joint

angle at address position between short golfer and tall golfer using three dimensional

analysis technique. All subjects were requested to drive 10 golf balls with sand wedge

and l0 golf balls with iron No 3. Best three of ten strokes with sand wedge and iron No

3 were selected for analysis.

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Pornthep Rachnavy Rぃiew Literame/6

CHAPTER II

LITERATURE REVIEW

The objective of this chapter is to encompass all notations and protocols

necessary for the understanding of peak hand velocity in golf swing. This chapter is

divided into two sections. The first section discusses about the background of golf

The second section discusses about the biomechanics of human skeletal muscle.

1. Background

The golf stroke is an underarm striking pattern (7,8) similar to throwing, with

modifications in the arm action. It might be called a reversed underarm pattern, since

for the right-handed performer, the left arm is the guiding force, and in the downward

swing the left arm action is in abduction rather than adduction. The skill also differs

from the usual underarm pattern in that both arms are active (Fig 1) Although the

right arm does contribute to the force, it is used mainly to support the club, except for

the hand action(8).

However, Broer and Houtz (9) have classified this skill as a sidearm pattern.

Broer and Houtz observed that there is greater activity in the muscles of the Ieft arm,

supporting their statements that this arm action contributes more force than the right.

This concept is subjected to debate. The sequences ofjoint involvement are the usual

hips, spine, and shoulders, with the wrist being last. No step is taken, since the feet doCopyright by Mahidol University

Fac of Grad.Studies,Mahidol Unv M.Sc.(Sport Science) / 7

not move from the starting position. The weight shifts to the right foot on the

backswing and back to the left foot on the forward swing. This shifting of weight

increases the range of hips rotation.

Figure 1 The golf swing

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Pornthep Rachnavy Roiew Literature/8

1.1 Basic Technique

The golf swing can be divided into 4 steps

I Address

2Back swing

3 Down swing

4 Follow through

1.1.1 Address

The address is a combination of grip, ball position, aim, stance and

posture.

1.1.1.1 Grip

There are three principal methods of gripping the club for driving

strokes the overlapping (or vardon) grip, the interlocking grip, and the baseball (or

two-handed) grip (10) With respect to the relative merits of these three, the results of

an experiment by Walker (1 1) are of interest. After comparing the performances of 24

male golfers who used each of the three grips in turn, Walker found that no one of the

grips was statistically superior to either of the others, in terms of greater distance or

accuracy.

1.1.1.2 Ball Position

Knowing the position of the low point helps understand the reason

for different ball positions. For instance, the ball is place halfuay between the feet forCopyright by Mahidol University

Fac.of Grad Studies,Mahidol Uni17 M.Sc.(Sport Science) / 9

all of the shorter irons (wedge through 5-iron) so that the ball will be hit with a more

downward blow. For the long irons (l through 4), the ball is played halfivay between

the center of the stance and the left heel. This position allows for a slightly downward,

more sweeping blow. With fairway woods, the ball is played offthe left heel so that the

club moves directly along the ground as it makes contact. When hitting with a driver,

the ball is played between the left heel and toe so that the club is beginning to ascend

slightly as it makes contact with the ball (9).

1.1.1.3 Aim

The alignment of your body and the clubface as you begin to swing

is crucialto the resulting ball flight. When you stand at address in a neutral, or square,

position, the clubface should be aligned square to the target (perpendicular to the line

between ball and target). Your body (feet, hips, and shoulders) should be aligned

parallel to the target line. This alignment lets the club swing on the intended path for a

Ionger time.

1.1.1.4 Stance

The placement of the feet relative to one another and relative to the

intended direction of the shot are of some importance in determining the velocity with

which the clubhead meets the ball.

If the feet are placed together, the narrowness of the base inevitably

makes the golfer conscious of the need to maintain balance and thus precludes a

maximum contribution of force from the muscles of the legs and hips. A stance withCopyright by Mahidol University

Pornthep Rachnavy Review Literature / l0

the feet wide apart also hampers the production of force by these muscles Logically,

therefore, most skilled players use a spread of their feet somewhere intermediate

between these two extremes-in general, slightly more than shoulders width apart-for

shots requiring maximum or near-maximum effort and a position with the feet closer

together for shorter shots requiring only a limited contribution from the legs and hips

(11)

1.1.1.5 Posture

The best way to experience proper posture is to stand erect with

the right foot square and the left foot turned out 35 degree parallel to an imaginary

target line. Then place your fingers on your hips joints in front of your front pockets,

and push your hips straight back, while the upper body bends forward about 30

degrees. Be sure to keep the back straight as the body bends forward. Now simply

bend the knees slightly, and you have the proper posture. It is important that the knees

stay bent throughout the swing about the same amount as bent at address. Either

bending or straightening the knees too much may make it difficult to turn properly,

reduce freedom of movement and throw offthe balance of the swing (9).

1.1.2 Backswing

Ihe purpose of the backswing is to put the golfer and the club into

the optimum position from which to start the downswing.

The backswing begins with a simultaneous backward movement of

the clubhead and the hands and a rotation of the trunk to the right.Copyright by Mahidol University

Fac. of Grad. Studies, Mahidol Univ. M.Sc.(Sport Science) / 1l

As the combined backward movement of the hands and club and

the rotation of the trunk continue, the left arm is raised and swung across the trunk,

the wrists are cocked (or bent sideways toward the thumbs), and the left forearm is

rolled so that the back of the left hand lines in an approximately vertical plane.

The end of the backswing is reached with the hands at or slightly

above head height, the trunk rotated approximately 90 degrees from its original

position, and the wrists cocked so that the club shaft Iies over and behind the head at

some 0-45 degrees above the horizontal.

According to Williams(l2) an objective examinatior of- the paths

followed by the hands and the clubhead during the upswings of top-class players reveal

that the path of the hands varies hardly at all from player to player while the path of the

clubhead varies considerably. He therefore concluded "that the path followed by the

clubhead in the upswing has little significance and is amatter of personalpreference".

1.1.3 Downswing

The objective on the downswing is to have the clubhead arrive at

the point of impact moving at maximum speed in the required direction and with the

face of the club "pointing" in that same direction.

The downswing begins with a forward movement of the hips that,

with good golfers, actually begins approximately 0.1 s before the clubhead reaches the

limit of its backswing (13). This movingforward of the hips rotates the whole upper

body and moves both levers through the first part of the downswing. The forces

responsible for this forward movement of the hips and the lesser forces exerted by theCopyright by Mahidol University

Pornthep Rachnavy Review Literature/12

same hips and leg muscles later in the downswing have been estimated to account for 2

ll2 hp (1864 W) of the total3-4 hp (2337-2983 W) generated in a good drive. Thus it

can readily be seen that "the muscles of the hips and legs constitute the main source of

power in Iong driving (14).

1.1.4 Follow Through

The follow-through, which serves the same purposes as it does in

other similar activities, consists of a gradual slowing down of the body and club

movements that led up to the moment of impact (10).

1.2 Factor Influencing Displacement

The objective in golf is simply to effect the displacement of the ball from

one position to another with the least number of shots possible. The initial position of

the ball is that in which the golfer places it on the tee and the desired final position is

within the hole some prescribed distance away (11) The relationships between the

displacement that a golf ball experiences and the factors that determine that

displacement are summarized in Fig (2).


Fac.ofGrad.Studies,Mhidol Univ M.Sc.(Sport SCiencc)ノ 13

Figure 2 Basic factor in golf

The displacement of the ball from one position to the other is usually

effected by a shot, or sequence of shots, in which the ball travels some distance

through the air and then bounces and rolls a farther distance. With the exception of

putting, the initial passage of the ball through the air (the carry) is generally responsible

for a greater proportion of the displacement achieved than is the bouncing and rolling

(the run) that follows (11).

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Pornthep Rachnavy Rぃ嗜ew Literame/14

1.2.1 The Carry

For any given case, the length ofcarry obtained depends on (1) the speed

and (2) the direction at which the ball leaves the face of the club, (3) the height of the

ball at that instant, and (4) the nature of the air resistance that it encounters in flight.

(11)

1.2.2 Speed of Release

The speed of any body immediately following an elastic impact is

governed by the masses and initial velocities of the bodies involved and by their mutual

coefficient of restitution. In the case of a golf ball struck by a club, three of these five

factors either are fixed by the rules of any subjects to such-little variation that they may

safely be regarded as constant. These are the mass of the ball (a. d; the initial

velocity of the ball (0 m/s); and the coefficient of restitution, which, although it varies

for differing speeds of impact, is essentially a function of the materials of which the

clubhead and ball are constructed.

Since each of the factors so far considered has been shown to allow liule

effective variation, it is apparent that observed differences in the speed at which the

ball leave the club must be mainly attributable to differences in the one remaining

factor-the speed of the clubhead at impact. Now since the clubhead is momentarily at

rest at the peak of the backswing, its speed at the instant of impact must be determined

by the forces exerted on the club during the downswing and the time over which these

forces act (impulse-momentum relationships). Of these forces (gravity, air resistance,

and the muscular forces applied to the grip), it is clearly the last that is capable of theCopyright by Mahidol University

Fac.of Grad Studies,Mttdol Un市 M.Sc.(Sport Science) / l5

widest variation. Differences in the speed at which the ball leaves the club are therefore

more likely to be due to differences in the muscular forces applied to the grip than to

differences in any other single factor (11).

1.2.3 Direction of Release

The direction in which the ball is moving at "release" must be considered

in terms of both the angles that the vector representing the velocity of the ball makes

with the horizontal (the angle of projection or release) and the angle it makes with the

intended line of the shot. These angles are measured in vertical and horizontal planes,

respectively (11)

l.2.4Height of Release

While the height of the ball at release, relative to the height of the point at

which it will land, is a significant factor in determining the length of carry, it is one

over which the golfer has very limited control (l l).

1.2.5 Air]Resistance

A golf ball in night is suttected tO fOrces exerted upon it by the air

through which it passes. These forces may be regarded as the summed ettcts of a

resistance to the linear modon ofthe ball through the air(drag)and a redstance to the

angular rnotion ofthe ban as it spins about an axls through its center ofgravity(11)


Pornihep Rachnary Rぃicw Literature/16

1.2.6 The Run

Of all those factors that have a part in determining what happens once the

ball hits the ground, the only one that is capable of much variation and is not essentially

fixed by the initial impact between club and ball is the coefficient of restitution. If the

coefficient of restitution is zero (that is, the impact is an inelastic one), the ball simply

imbeds itself in the ground at the point at which it lands. However, if the coefficient of

restitution is greater than zero, as is normally the case, the ball bounces following

impact with the ground. In such instances the distance covered during the bounce (and

during each successive bounce depends very largely on the magnitude of the

coefficient. For example, if the ground is hard and the coefficibnt is therefore high, the

ball is likely to cover greater distances with each bounce and to bounce more often

than it would if the ground were soft.

After a number of bounces the vertical velocity with which the ball strikes

the ground decreases to the point where the ground-reaction force is insufficient to

carry it once more into the air. At this point the ball begins to roll, the distance it rolls

being governed by its horizontal velocity at the time and by the forces (for example,

gravity and rolling friction) that subsequently act upon it (1 l).

1.3 Factors Influencing Speed

The longer the club and the golfer's arms, the greater the velocity of

which the clubhead is capable since the clubhead travels through a longer arc in a given

time and therefore, moves faster. The length of the arc is also determined by the length

of backing. Since the longer this arc, the more time available to work up momentum,

い


Fac.of Grad.Studes,Mahidol U」v. M.Sc.(Sport Science) / 17

when maximum force is desired the backswing should be as long as possible without

loss of control. If the backswing is so long that the clubhead drops below the

horizontal, it must be raised against the force of gravity as the downswing begins. The

clubhead is likely to lag behind the hands and unless the golfer has strong wrists which,

despite this lag, can bring the clubhead will be angled to the right when contact with

the ball is made. The long backswing also brings into play more muscles which can

contribute to the swing and therefore more force is possible. The only muscular force

available when a short backswing is used is that of the arms and shoulders girdle. As

the backswing is lengthened by trunk rotation the strong trunk muscles are added to

the movement. In gol[, as in all sidearm throwing and striking activities, a long

backswing necessitates a position of the body sideways to the intended line of flight of

the ball. This body position also places the ball at the center of the arc of the swing

which is the point at which the clubhead is moving the fastest.

Follow-through is important to speed at impact just as it is in any

throwing or striking activity. The speed with which the muscles involved in the

movement contract is also a considerable factor in the speed of movement of the

clubhead. The faster the muscular contraction, again up to the point of loss of control,

the greater the velocity of the clubhead at contact. It is certainly possible to swing so

fast that control is lost. Here again the hands may be brought through well ahead of the

clubhead because the air resistance against the clubhead, increasing rapidly as speed

increases and being applied so far from the fulcrum, makes it difficult to snap the wrists

through and bring the striking surface in line with the hands at impact. This does not

mean however, that the beginner should practice the golf swing at a slow tempo. It has

!.


Pornthep Rachnarry Review Literature / l8

been shown experimentally that skill in activities involving both accuracy and speed is

developed more readily when the activity is practiced from the beginning at the speed

(or approximate speed) at which it will be performed.

Stance plays an important part in the speed of the clubhead in that it

makes it possible to use the entire body in the swing through weight transference from

the back to the forward foot. It is also important from the standpoint of equilibrium.

Since the force is moving from right to left (right-handed golfer) it is important to

widen the stance in that direction. If equilibrium were to be maintained on a narrow

base the length of the swing would have to be cut considerably. If the feet are placed

farther apart than the width of the hips, rotation on the backswing and follow-through

are restricted and thus loss of length of swing, and consequent loss of force, result.

Beyond the width of the hips the farther apart the feet are placed the greater the

curtailment of the swing.

Transference of weight, besides contribution to force by putting the body

weight into the stroke, moves the center of the arc (the shoulders) slightly forward and

thus flattens the vertical arc of the swing, giving more time in the swing during which

the clubhead can hit through the center of the ball in the direction of desire movement.

Only if the ball is contacted through the center of gravity is all the force available

imparted to the ball.,If the ball is hit above its center, some of the force pushes the ball

into the ground rather than sending it forward. When the ball lies on a hard sur ce and

a wood is used, the contact is normally above center. The driving tee is important in

that it lifts the ball making it possible to hit through, or slightly under, its center of


Fac.of Grad.Studes,Mamd01 umv M.Sc.(Sport Science) / 19

gravity. If the ball lies on grass, the clubhead can get down into the grass for a clear

contact.

The degree to which the force produced by the body is effective in

moving the ball depends upon the firmness of the grip and the wrists at impact.

Firmness of wrists and grip prevents any recoil of the clubhead at the time of contact

which would dissipate some of the force, and insures the transference of all of the

available force to the ball.

Various grips have been suggested, the overlapping, interlocking, and the

"baseball" grip. Bunn (I5) analyzed the striking movement of the hands as a pushing

back of the top hand as the bottom hand pushes forward, the fulcrum being halfway

between the hands. This action can be more effectively executed with the hands spread

as in the "baseball" grip because the force arm is lengthened. He stated that this "split-

second action of the wrists at the moment of contact gives the needed extra force

which produces distance." Other authors (16,17,18) have indicated that the greatest

force which can be developed with a given amount of body power, is centrifugal in

nature. This is best accomplished when the hands act as a unit rather than applying a

leverage action. The overlapping grip, because the hands are in contact, makes this

easier. It is possible that while one individual may be able to control the leverage action

of the hands suggested byBunn and take advantage of any extra force thus produced,

another might find that the "baseball" grip leads to loss of control and that he is able to

generate more controlled force through the use of centrifugal force unintemrpted by

the leverage action.



The degree to which the force produced by the body is transferred to the

ball also depends upon the counterpressure of the ground against the feet. Any slipping

of the feet means a loss of force against the ball since some of the force goes into

moving the foot or feet. For this reason cleats on golfers' shoes aid in imparting force

to the ball. Since the cleats indent or actually pierce the ground, they offer a surface

which can push directly against a vertical surface of the ground rather than an area

which pushes across a hoizontal surface in which case the counterpressure is entirely

dependent on friction. If the feet are directly under the hips as they are when the stance

is widened only to the width of the hips, the pressure of the feet is more directly

downward and slipping is less likely to occur. When the feet are placed apart farther

than the width of the hips a more diagonal force is applied and the outward component

of this force makes slipping more likely unless cleats are worn.

The speed imparted to the golf ball, as to any other ball, is also dependent

upon the coefficient of restitution of the ball and the clubhead If the ball has lost some

of its ability to retake its original shape after being flattened by contact with the.\clubhead, some of the force is dissipated in the change of shape and does not

contribute to speed (7).

1.4 Factors fnfluencing Direction

The direction of the flight of a golf ball is influenced by the direction in

which the clubhead is moving at impact, the angle of the face of th6 clubhead (law of

rebound), the relationships of the clubhead to the ball's center of gravity, the firmness

of the grip and the wrists at impact, any outside force acting on it (the wind), and spin.Copyright by Mahidol University

Fac.of Grad Studics,Mahdol Univ M.Sc.(Sport Science) / 2l

When the clubhead hits through the center of gravity of the ball the force

caused by the momentum of the clubhead is applied to the ball in the direction that the

clubhead is moving at impact. If moving in an arc, this force is applied in the direction

of the tangent to the Nc at the point of contact. Since the ball is stationary the rebound

force and this force in the direction of the movement of the clubhead (or the tangent to

the arc) are equal, both being caused by the momentum of the clubhead, and therefore

the ball departs approximately at right angles to the face of the clubhead. Variations in

ball compression will alter this somewhat.

It follows that the more nearly the face of the club is at right angles to the

desired path of the ball at impact the nearer to the desired path the ball will travel. This

means that if a ball is to go straight ahead the clubhead must be moving straight

forward and must face straight ahead at impact. To assure this the stroke is begun by

placing the clubhead in this position and taking a stance with the toes along a line

parallel to the desired flight of the ball (square stance). Having a straight forward path

of the clubhead with the face perpendicular at impact is more easily accomplished if the

clubhead follows a path along the line of the desired direction of the shot both before

and after impact. The square stance aids in keeping the swing along this path. If the left

foot (right-handed golfer) is forward (closed stance the path of the swing tends to

move toward the right instead of straight ahead since the follow-tkough straight ahead

is restricted. If the right foot is forward (open stance) the opposite is true. The

backswing being restricted the path of the swing tends to be move toward the left.

The force of impact causes the club to turn in the hands if the grip is not

firm, or causes the face of the clubhead to turn if the wrists are not firm, when the ballCopyright by Mahidol University

Pornthep Rachnavy Re宙ew Literane/22

is contacted. When this happens the direction which the ball will take is unpredictable.

Only when the grip and wrists are firm does the face of the clubhead remain

perpendicular to the path of the clubhead as the ball is contacted.

Since the golf ball moves through the air at a high velocity, air pressure

builds up rapidly. Therefore, spin modifies the flight of a golf ball considerably.

If the clubhead moves across the back of the ball from the outside-in

(from right to left), with its face square to the line of flight, the ball is given right spin

and its flight curves to the right (a slice). If the face is closed (angled to the left), the

ball is pulled to the left. Because of the restriction of backswing this outside-in

movement is facilitated by an open stance, though it is possible even with a square

stance if the clubhead is thrown away from the body on the downswing. This can be

corrected by placing a piece of paper or a handkerchief between the right upper arm

and the trunk and attempting to hold it there until the ball is contacted. A slice can also

be caused by a lag of the clubhead behind the wrists through too late, or to a lack of

sufficient wrist strength to control such a long lever. Many women are never successful

in using a number one wood for this reason. If the sequence of movement does not

flow from the center of the body out to the extremities but rather starts with the arms

and the body rotation is retarded, the clubhead tends to hit across the back ofthe ball

from outside-in causing a slice.

If the clubhead moves across the back or the ball from the inside-out (left

to right), with its face square to the line of flight, the ball is given Ieft spin and its flight

curves to the left (a hook). If the face is open (angled to the right), the ball is pushed to

the right. This inside-out movement is facilitated by a closed stance since the follow-Copyright by Mahidol University

Fac. of Grad. Studies, Mahidol Univ. M.Sc.(Sport Science) / 23

through is restricted, but it may result from hugging the right arm too close to the body

on the downswing and then throwing it outward at impact. If the sequence of

movement is intemrpted or if the arms lag behind the body rotation, the clubhead will

also be pulled across the ball from the inside-out.

In determining the desired direction of a shot the wind must be

considered. Since the golf ball travels well up in the air, a cross wind has considerable

effect upon the direction of its flight. The ball is carried with the win If the wind is

blowing from the left to the right the ball must be aimed left to the hole, and if blowing

from right to left, to the right of the hole. In other words, it should be aimed into the

wind. How much the angle of the path of the ball needs to be adjusted depends upon

the force of the win tends to have less velocity.

Allowance must also be made for various contours of fairways and

greens. Since a ball rolls down slope due to the pull of gravity, a shot must be aimed

uphill of the green or the cup (7),

1.5 Factors fnfluencing Distanc

As with any projectile the distance a ball travels depends upon the force

imparted to it by the clubhead, the angle at which the force is applied, and the spin

imparted to the ball.

The first, the force imparted, has been discussed. The vertical angle of

application of the force depends upon the inclination of the clubface. The greater the

angle of inclination of the face of the clubhead, the smaller the forward component and

the greater the upward component of the force applied by it. Since the ball is projectedCopyright by Mahidol University


at right angles to the striking surface, the more vertical the clubface the more distance

and the less height obtainable. Owing to the strong air resistance created by the great

speed of the golf ball, the optimum angle for distance is considerably less than the

theoretical 45 degrees. A larger horizontal component is needed to overcome the air

resistance. A club with a more nearly vertical face should be chosen when maximum

distance is desire and as less distance and more height are desired clubs with

progressively more open faces should be used.

Spin affects the distance a ball travels since top spin makes a ball drop

faster and back spin keeps it in the air longer against gravity's pull. When a ball is

contacted below its center, back spin results. It has been pointed out that even the

driver, which has the most vertical face of all the club (with the exception of the

putter), has enough loft so that the ball is contacted slightly below center and imparts

some back spin to the ball. Some back spin is desirable to stabilize flight in the vertical

plane and to keep the ball in the air longer. As the club loft increases the point of

contact on the ball is lower. Harvey(l9), in an article in Golfing magazine, clearly

explained the way spin is imparted to the golf ball. He stated that only up to a point

does the golf ball follow the rule that the lower the ball is contacted the greater the

spin. Since the ball leaves the clubface quicker and flattens less as the angle of

divergence between the path that the clubhead is traveling and the line of flight of the

ball increases, with the more lofted clubs there is less flattening of the ball, less contact

time and thus less back spin. He further stated that the number five iron imparts the

most back spin because the angle of inclination of its face is the greatest at which there

is enough flattening to permit the grooves on the face become narrower and shallowerCopyright by Mahidol University


as for as their effect on the ball is concerned and they do not hold the ball, contact time

is less, and back spin is less.

Back spin can also be produced by hitting downward across the back of

the ball. When the ball is hit at the center of arc of the swing with the club in its natural

position, it is hit a horizontal blow which results in some back spin because the ball is

contacted below center. The amount of spin depends upon how much below the center

the ball is contacted, the length of time the grooves of the club keep the ball in contact,

and the amount the ball is flattened. When the golf ball is played back of the center of

the stance, it is hit a downward blow, the club passes downward across the back of the

ball, and back spin results. The farther back the ball is played the more downward is

the hit and the more back spin is imparted to the ball. Harvey (19) also pointed out

that, if the ball is played on a hard surface, a downward hit pinches the ball between

the ground and the clubhead increasing back spin. However, if the surface is heavy

grass, the pinching effect is not as great because of the give of the soft surface, and less

back spin results. Although the surface of a sand trap gives, the sand increases the

friction between the clubface and the ball preventing slipping and increasing contact

time and thus more back spin than is normal for a particular club is imparted. This is

not true when an explosion shot, in which the sand taken during the shot keeps the

clubhead from actually contacting the ball, is used.

Spin also affects distance in that the dimples on a spinning ball carry atr

around the ball smoothing out the air flow at the back of the ball and thus stabilizing

flight. Spin is also an important factor in the roll of the ball after it lands. The more the

back spin the less the roll, since the force of the spin against'the ground is opposite to


Pornthep Rachnavy Review Literaire / 26

the direction of movement of the ball. Therefore, for distance shots, only enough back

spin to stabilize the flight and keep the ball in the air a little longer is desirable. The

back spin should be minimized, as it is when clubs with a more vertical face are used,

so that when the ball landS the forward force can easily overcome the back spin force

reversing the spin and allowing the ball to roll forward. A great deal of back spin is

desirable on approach shots to the green in which little or no roll is desired. Therefore,

the ball is played farther back so that it will be hit a downward blow. However, it must

be pointed out that the farther back the ball is played, the more open (angled to the

right) is the face of the club at contact and therefore, the toe of the club must be

moved forward to keep the face perpendicular to the line of flight. This moving of the

toe forward reduces the vertical angle of the face of the club and as a result less loft,

although more back spin, results. In general, for maximum distance, a long club with a

more vertical face is chosen and the ball is placed near the center of the stance so that

the ball is given ahoizantal blow and very little back spin. A shorter club with a more

open face is chosen and the ball is moved gradually back toward the right foot as less

distance and less roll are desired, until in playrng a minimum roll pitch shot it is placed

almost opposite the right heel. If a high shot with less back spin is desired, as when the

golfer needs to play the ball over the branches of a tree but desires to have it roll on

landing, a club with an open face is chosen and the ball is placed forward of the point

that would normally be used for the particular club. In this case, unless the toe of the

club is moved back, the clubhead will be closed at corrtact (angled to the left). Moving

the toe back increases the vertical angle of the club face and thus results in more loft,


Fac. of Grad. Studies, Mahidol Univ.

although less back spin, all other things being equal

would prevent roll on landing, is minimized.

M.Sc.(Sport Science) / 27

In this way back which

The contour and condition of the ground also affect the distance of a shot

in that they are important factors in the bounce and roll of the ball. When the ground is

hard it absorbs little or no force of the ball as it lands, most of the force is transferred

back to the ball and the ball bounces and rolls. Hard ground does not give with the

weight of the ball as it rolls and therefore, of,Eers little resistance and the ball rolls

farther for a given force than it does on soft ground. In the case ofsoft ground a great

deal of resistance is offered to the forward roll or the ball because the ground gives

with the weight of the ball, in effect, forming a series of vertical walls in front of the

ball which must be pushed down with each turn of the ball. Bounce and roll are also

less because agreat deal of the force of the ball is absorbed when the ball first strikes

the ground. The longer the grass the softer the surface, the more force is absorbed on

landing and the gteater the resistance to the forward roll of the ball. Wet grass offers

more resistance to a rolling ball than dry grass and, all other things being equal, a ball

rolls farther on dry than wet grass. In putting, therefore, the longer and wetter the

grass the longer the backswing and follow-through must be to roll the ball a given

distancit6 the cup.

Choice of club is also affected by various lies on the fairway. While it

may seem that an uphill lie demands a club with a more open face to lift the ball up the

hill, the opposite is actually the case. Since the golfer is standing on an uphill slope the

swing of the club is in an uphill direction and therefore imparts upward force, and a

club with a less angled face than would be normally chosen is needed. This is not to be

spin,


Pornthep Rachnavy Revicw Literaturc/28

confused with a flat lie at the foot of a hill in which case the golfer does not stand on

the hill and so the swing is forward, not upward, and a club with an open face would

be needed. When standing on a downward slope (downhill lie) the swing is downward

and in order to lift the ball to send it out from the slope and straight ahead, a club with

an open face is required. Sidehill lies affect the length of the club chosen. When the ball

which must be hit across a hill lies below the golfer the distance from shoulders to ball

is farther than usual and a club with a longer shaft needs to be used. When the ball lies

above the golfer the opposite is true, the distance from shoulders to ball is.reduced and

either the grip on the club must be shortened or a shorter club must be chosen. It must

be less vertical and more horizontal.

1.6 The Club

Golf clubs are designed so that the ball hit varying distances and

heights, as needed to make the shot, without changing your basic swing appreciably.

The differences in ball flight are related to the degree of loft or angle of the clubface

and the length of the shaft.

For instance, the driver has a very long shaft (between 41 and 48 inches),

so that maximum clubhead speed can be developed, and a very shallow face (between

7 and 13 degree), so the ball can be hit on a low trajectory for maximum distance. On

the other hand, the wedge has a short shaft and very lofted face (tilted back about 45

to 60 degrees from vertical), so that the ball is hit only a short distance but very high

and soft so that when it lands on the green, it will stop.

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Fac of Grad Studes,Mamdol Univ. M.Sc.(Sport Science) / 29

As a general rule, the longer the club, the longer the swing arc, and the

farther the ball will go. The higher the number of the club (e.g., 9 vs. 3), the shorter it

is, and the more loft it has. Longer clubs also have a flatter lie because they extend

farther from the body (9).

Figure 3 A full set of 14 clubs

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Pornthep Rachnavy 陽 view Literaturc/30

Table l The United State GolfAssociation standard clubs

2. The Biomechanics of Human Skeletal Muscle

2.1 Length-Tension Relationships

The amount of maximum isometric tension a muscle is capable of


isolated muscle preparations, force generation is at its peak when the muscle is at

normal resting length (neither stretched nor contracted). When the length of the muscle

increases or decreases beyond .resting length, the maximum force the muscle can

produce decreases, following the form of a bell-shaped curve(4).

CLUB DEGREE OF LIEfDEGREE〕

LENGTⅡ(INCⅡES)

One-wood 55 43

Two-wood 551/4 421/2

Three-wood 551/2 42

Four-wood 553/4 411/2

Five-wood 56 41

One -iron 55 39

Two-iron 56 38 1/2

Three-iron 57 38

Four-iron 58 37 1/2

F ve-lron 59 37

S x-lron 60 361/2

Seven-iron 61 36

Eieht-iron 62 35 1/2

Nine-iron 63 35

Pitchine wedge 63 35

Sand wedge 63 35


Fac of Grad Studics,Mahidol U面 v M.Sc.(Sport Science) / 31

Within the human body, however, force generation capability increases

when the muscle is slightly stretched. Parallel-fibered muscles produce maximum

tensions at just over resting lengh, and pennate-fibered muscles generate maximum

tensions at between 120% and l30Yo of resting length (5) This phenomenon is due to

the contribution of the elastic components of muscle, which add to the tension present

in the muscle when the muscle is stretched. Research indicates that following eccentric

exercise there may be a slight, transient increase in muscle length that impairs force

development when joint angle does not place the muscle in sufficient stretch (6).

2.2 The Biomechanics of the Human Upper Extremity

2.2.1, Structure of the Shoulders

The shoulders is the most complex joint in the human body, largely

because it includes four separate articulations: the glenohumeral joint, the

sternoclavicular joint, the acromioclavicular joint, the coracoclavicular joint, and the

scapulotheoracic joint. The glenohumeral joint is the articulation between the head of

the humerus and the glenoid fossa of the scapula, which is the ball and socket joint

typically considered as the major shoulders joint. The sternoclavicular and

acromioclavicular joints provide mobility for the clavicle and the scapula bones of the

shoulders girdle (20).


Pornthep Rachnavy bicw Literature/32

2.2.2 Movements of the Shoulders Complex

Although some amount of glenohumeral motion may occur while the

other shoulders articulations remain stabilized, movement of humerus more commonly

involves some movement at all three-shoulder joints. As the arm is elevated in both

abduction and flexion, rotation of the scapula accounts for part of the total humeral

range of motion. Although the absolute positions of the humerus and scapula vary due

to anatomical variations among individuals, a general pattern persists (21) During

about the first 30 degrees of humeral elevation, the contribution of the scapula is only

about one-fifth that of the glenohumeral joint (22). As elevation proceeds beyond 30

degrees, the scapula rotates approximately 1 degree for every 2 degrees of movement

of the humerus (23,24,25). This important coordination of scapular and humeral

movements, known as scapulohumeral rhythm, enables a much greater range of motion

at the shoulders than if the scapula were fixed. During the first 90 degrees of arm

elevation (in sagittal, frontal, or diagonal planes), the clavicle is also elevated through

approximately 35 to 40 degrees of motion at the sternoclavicular joint (22) Rotation

at the acromioclavicular joint occurs during the first 30 degrees of humeral elevation

and again as the arm is moved from 135 degrees to maximum elevation (26).

Positioning of the humerus is further facilitated by motions of the spine.


Fac of Grad Studes,Mahidol U面v

Table 2 Mttor musde ofthe shOulders

M.Sc.(Sport Science) / 33

MUSCLES OF THE SⅡ OULDERSMUSCLE PROXIMAL

ATTACHMENTDISTAL

ATTACIMENTPRIMARYACTIONS

ABOUT THESⅡOULDERS

Deltoid (Anterior) Outer third of theclavicle

Deltoid tuberosityof the humerus

FIexion, horizontalof adduction

(Middle) Top of theacromlon

Deltoid tuberosityof the humerus

Abduction,horizontalabduction

@osterior) Scapular spine Deltoid tuberosityof the humerus

Extension,horizontalabduction

Pectoralis major(Clavicular)

Medial half of theclavicle

Lateral aspect ofthe humerus justbelow the head

Flexion, horizontaladduction

(Sternal) Anterior sternumand cartilage of first

six ribs

Laterd, aspect ofthe humerus justbelow the head

Extension,adduction,horizontaladduction

Supraspinatus Suprasipinous fossa Greater tuberosityof the humerus

Abduction, assists

with lateral rotationCoracobrachialis Coracoid process

of the scapulaMedial anterior

humerusFlexion, adduction,

horizontaladduction

Latissimus dorsi Lower six thoracicand all lumbar

bertebrae, posteriorsacrum, iliac crest,

lower three ribs

Anterior humerus Extension,adduction, medial

rotation

Teres major Lower, lateral,dorsal scapula

Anterior humerus Extension,adduction, medial

rotationInfraspinatus Infraspinous fossa Greater tubercle of

the humerusLaterd, rotation,

horizontalabduction

Teres minor Posterior, lateralborder ofscapula

Greater tubercleand adjacent shaft

of humerus

Lateral rotation,horizontalabduction

Subscapularis Entire anteriorsurface ofscapula

Lesser tubercle ofthe humerus

Medial rotation

Biceps brachii (longhead)

Upper rim of theglenoid fossa

Tuberosity oftheradius

Assists withabduction

′う枠′5ι l


Pornthep Rachnavy Review Literafire / 34

Table 2Major muscle ofthe shoulders (Cont.)

2.3 The Biomechanics of the Human Lower Extremity

2.3.1 Structure of the Hip

The hip is a ball and socket joint. The ball is the head of the femur, which

forms approximately two-thirds of a sphere. The socket is the concave acetabulum,

which is ambled obliquely in an anteior,lateral, and inferior direction. Joint cartilage

covers both articulating sur ces. The cartilage on the acetabulum is thicker around its

periphery, where it merges with a rim, or labrum, of fibrocartilage that contributes to

the stability of the joint. The acetabulum also provides a much deeper socket than the

glenoid fossa of the shoulders joint, and the bony structure of the hips is therefore

much more stable or less likely to dislocate than that of the shoulders.

Several large, strong ligaments also contribute to the stability of the hips.

The extremely strong iliofemoral or Y ligament and the pubofemoral ligament

strengthen the joint capsule anteriorly, with posterior reinforcement from the

ischiofemoral ligament. Tension in these major ligament acts to twist the head of the

MUSCLES OF TⅡ E SⅡOULDERSMUSCLE PROXIMAL

ATTACⅡMENTDISTAL

ATTACⅡMENTPRIMARYACTIONS

ABOUT TⅡESⅡOULDERS

(Short head) Coracoid process

of the scapulaTuberosity of the

radiusAssists with flexion,adduction, medial

rotation, and

horizontaladduction

Triceps brachii(long head)

Just inferior to theglenoid fossa

Olecranon process

of the ulnaAssists with

extension and

adduction



femur into the acetabulum during hips extension, as when a person rises from sitting to

an upright standing position. Inside the joint capsule, the ligamentum teres supplies a

direct attachment from the rim of the acetabulum to the head of the femur.

As with the shoulders joint, several bursae are present in the surrounding

tissues to assist with lubrication. The most prominent among the bursae are the

iliopsoas bursa and the deep trochanteric bursa. The iliopsoas bursa is positioned

between the iliopsoas and the articular capsule, serving to reduce the friction between

these structures. The deep trochanteric bursa provides a cushion between the greater

trochanter of the femur and the gluteus maximus at the site of its attachment to the

iliotibial tract.

The femur is a major weightbearing bone and is the longest, largest, and

strongest bone in the body. Its weakest component is the femoral neck, which is

smaller in diameter than the rest of the bone and weak internally because it is primarily

composed of trabecular bone.

2.3.2Movements at the Hip

Although movements of the femur are primarily due to rotation occurring

at the hips joint, the pelvic girdle has a function similar to that of the shoulders girdle in

positioning the hips joint for effective limb movement. Unlike the shoulders girdle, the

pelvis is a single nonjointed structure, but it can rotate in all three planes of movement.

The pelvis facilitates movement of the femur by rotating so that the acetabulum is

positioned toward the direction of impending femoral movement. For example,

posterior peMc tilt, with the anterior superior iliac spine tilted backward with respectCopyright by Mahidol University

Pornthep Rachnavy Review Literatwe I 36

to the acetabulum, positions the head of the femur in front of the hipbone to enable

ease of flexion. Likewise, anterior pelvic tilt promotes femoral extension, and lateral

pelvic tilt toward the opposite side facilitates lateral movements of the femur.

Movement of the pelvic girdle also coordinates with certain movements of the spine.

Table 3 The major muscle of the hips

MUSCLE OF TIIE ⅡIPS

MUSCLE PROXIMALATTACⅡMENT

DISTALATTACⅡMENT

PRⅡ旺ARYACTION(S)ABOUT TⅡE

IIIPS

Rectus femoris Anterior inferioriliac spine

Patella Flexion

Iliopsoas (Iliacus) Iliac fossa andadiacent s'acrum

Lesser trochanterof the femur

Flexion

@soas) 12* thoracic and

lumbar vertebraeand lumbar discs

Lesser trochanterof the femur

Flexion

Sartorius Anterior superioriliac spine

Upper medial tibia Assists with flexion,abduction, and

lateral rotationPectineus Pectineal crest of

pubic ramus

Medial femur Flexion, adductionand lateral rotation

Tensor fascia latae Crest ofthe ilium Iliotibial band Assists with flexion,abduction, and

medial rotation

Gluteus maximus Posterior ilium, iliaccrest, sacrurq and

coccyx

Gluteal tuberosityof the femur and

iliotibial band

Extension, lateralrotation

Gleteus medius Between posteriorand anterior gluteal

lines on theposterior ilium

Superior, lateralgreater trochanter

Abduction, medialrotation

Gluteus minimus Between anteriorand inferior gluteal

lines on theposterior ilium

Anterior surface ofthe greatertrochanter

Abduction, medialrotation

Gracilis Anterior, inferiorsr.,rnphvsis pubis

Medial pro対mal

tibia

AdductionCopyright by Mahidol University

Fac of Grad Studies,Mand01 u面v

Tab19 3 The mttOr muSCle Ofthe hips(COnt)

M SC(Sport science)ノ 37

MUSCLE OF TⅡEll■rSMUSCLE PROXIMAL

ATTACⅡMENTDISTAL

ATTACⅡMENTPRコⅦARYACTION(S)ABOUT TⅡE

■l■rSAdductor magnus Inferior ramus of

pubis and ischiumEntire linea aspera Adduction, lateral

rotationAdductor longus Anterior pubis Middle linea aspera Adduction,lateral

rotation, assists

with flexionAdductor brevis Inferior ramus of

the pubisUpper linea aspera Adduction, lateral

rotationSemitendinosus Medial ischial

tuberosityPrO対mal,medial

tibia

Extension

Semimembranosus Lateral ischialtuberositv

Pro対mal,medial

tibia

Extension

・印鈍Ｂ femoris

head)Lateral ischial

tuberosityPosterior lateralcondyle of tibia,head offibula

Extension of thigh

The six outwardrotators

Sacrum, ilium, and

ischiumPosterior greater

trochanterOutward rotation

2.3.3 Structure of the Knee

The structure of the knee permits the bearing of tremendous loads as well

as the mobility required for locomotor activities. The knee is a large synovial joint,

including three artculations within the joint capsule. The weightbearing joints are the

two-condylar articulations of the tibiofemoral joint, with the third articulation being the

patellofemoral joint. Although not a part of the knees, the proximal tibiofibular joint

has soft-tissue connections that also slightly influence knees motion.

2.3.4Movements at the Knee

Like the elbow, the knee is crossed by a number of two-joint muscles.

The primary actions of the muscles crossing the knees are summaizedin Table (4).Copyright by Mahidol University

Pornthep Rachnavy

Table 4 Major muscles of the knees

bicw Literature/38

MUSCLE OF THE KNEESMUSCLE PROXIMAL

ATTACⅡMENTDISTAL

ATTACⅡMENTPRIMARYACTION(S)ABOUT THE

KNEESRectus femoris Anterior inferior

iliac spine

patella Extension

Vastus laterlis Greater trochanterand lateral linea

aspera

Patella Extension

Vastus intermedius Anterior femur Patella Extension

Vastus medialis Medial linea aspera patella Extension

Semitendinosus Medial ischial

tuberositvPro対mal,medial

tibia

Flexion and medialrotation

Semimembranosus Lateral linea aspera Posterior lateralcondyle of tibia,head offibula

Flexion and lateralrotation

Biceps femoris(short head)

Lateral linea aspera Posterior Iateralcondyle of tibia,head offibula

Flexion and lateralrotation

Sartorius Anterior superioriliac spine

Upper medial tibia Assists with flexionand lateral rotation

of thiehGracilis Anterior, inferior

svmphvsis pubisMedial,pro対mal

tibia

Adduction of thigh,flexion of lower leg

Popliteus Lateral condyle ofthe femur

Medial,poste● or

tibia

Medial rotation and

flexion of lower leg

Gastrocnemius Posterior medial &lateral condyles of

the femur

Tuberosity of thecalcaneus by theAchilles tendon

Flexion

Plantans Distal, Posteriorfemur


Flexion



2.3.5 Structure of the Ankle

The ankles region includes the distal tibiofibular, tibiotalar, and fibulotalar

joints. The distal tibiofibular joint is a syndesmosis where dense fibrous tissue binds the

bones together. The joint is supported by the anterior and posterior tibiofibular

ligaments, as well as by the crural interosseous tibiofibular ligament. Most motion at

the ankles occurs at the tibiotalar hinge joint, where the convex surface of the superior

talus articulates with the concave surface of the distal tibia. All three articulations are

enclosed in a joint capsule that is thickened on the medial side and extremely thin on

the posterior side. Three ligaments-the anterior and posterior talofibular and the

calcaneofibular reinforce the joint capsule laterally. The four bands of the deltoid

ligament contribute to joint stability on the medial side (20)

2.3.6 Movements at the Ankle

The axis of rotation at the ankles is essentially frontal, although it is

slightly oblique and its orientation changes somewhat as rotation occurs at the joint.

Motion at the ankles occurs primarily in the sagittal plane, with the ankles functioning

as a hinge joint during the stance phase of gait (27) AnHe flexion and extension are

termed dorsiflexion and plantar flexion, respectively. Dorsiflexion of 25 degrees also

involves approximately 2.5 degrees of external rotation of the foot, and plantar flexion

to 35 degree is associated with slight internal rotation of the foot, on the order of less

than 1 degree (28). In the loaded ankles, l0 degrees of dorsiflexion is accompained by

1.6 degrees of eversion and2.1 degrees of internal tibial rotation, with 10 degrees of


Pornthep Rachnaly Review Literature / 40

plantar flexion resulting in 1.6 degrees of inversion and 1.3 degrees of external rotation

of the tibia (29).

The medial and lateral malleoli serve as pulleys to channel the tendons of

muscles crossing the ankles either posterior or anterior to the axis of rotation, thereby

enabling their contributions to either dorsiflexion or plantar flexion.

The major plantar flexors are the two heads of the powerfitl two-joint

gastrocnemius and the soleus, which lies beneath the gastrocnemius. Assistant plantar

flexors include the tibialis posterior, peroneus longus, peroneus brevis, plantaris, flexor

hallucis longus, and flexor digitorum longus(20).

Table 5 Major muscle of the ankle: and foot

MUSCLES OF TⅡE ANKLES AND F00TMUSCLE PROXΠⅦAL

ATTACⅡMENTDISTAL

ATTACⅡMENTPRIMARYACTIONfS)

Tibialis anteHor Upper two-thirdslateral tibia

Medial surface offirst cuneiform and

first metatarsal

Dorsiflexion,inversion

Extensor digitorumlongus

Upper three-fourthsanterior fibula

Second and thirdphalanges offour

lesser toes

Dorsiflexion,eversion

Peroneus tertius Lower thirdanterior fibula

Dorsal surface offifth metatarsal

Dorsiflexion,eversion

Extensor hallucislongus

Middle ante五 or

ibula

Dorsal surface ofdistal phalanx of

great toe

Dorsiflexion,inversion, and

hallux extension

Gastrocnemius Posterior medial &lateral condyles of

the femur


Plantar flexion

Plantaris Distal, posteriorfemur


Assists with platarflexion

Soleus Poste五or upper

flbula and iniddle

tibia


Plantar flexion


Fac of Grad Stu(五 es,Mand。 l univ

Table 5 Mttor musde ofthe arttes and foot(COnt)

M.Sc.(Sport Science) / 4l

MUSCLES OF TⅡE ANKLES AND F00TMUSCLE PROXIMAL

ATTACⅡMENTDISTAL

ATTACHMENTPRIMARYACTION(S)

Peroneus longus Lateral upper two-thirds fibula

Lateral surface offirst cuneiform and

first metatarsal

Plantar flexion,eversion

Peroneus brevis Distal two― thirds

flbula

Lateral fifthmetatarsal

Plantar glexion,eversion

Flexor digitorum' longusPosterior tibia Distal phalanx of

four lesser toes

Plantar flexion,inversion, toe

flexionFlexor hallucis

Iongus

Lower two-thirdsposterior fibula

Distal phalanx ofthe great toe

Plantar flexion,inversion, toe

flexion

Tibialis posterior PosteHor upper

two―thirds tibia and

flbula

Cuboid, naviclar,calcaneus, and allthree cuneiforms

Plantar flexion,inversion

The golf swing, presents a more complicated picture of shoulders muscle

function because the left and right arms must work in concert, producing opposite

movements and using opposing muscles to produce the action. The golf swing can be

divided into four phases: the takeaway, forward swing, acceleration, and follow-

through.

In the takeaway phase for a right-handed golfer, the club is brought up

and back behind the body as the left arm comes across the body and the right arm

adducts minimally. The shoulders muscular ac;tivity in this phase is minimal except for

moderate subscapularis activity on the left arm to produce internal rotation, and

marked activity from the supraspinatus on the right side to abduct l.he arm.

In the next phase, the forward swing, movement of the club is initiated in

the forward direction by moderate activity from the latissimus dorsi and subscapularis

on the Ieft side. On the right side, there is accompanying high activity from theCopyright by Mahidol University

Pornthep Rachnavy Review Literature / 42

supraspinatus and the deltoid. This phase brings the club around the shoulder level

through continued internal rotation of the left arm and the initiation of internal rotation

of the right arm with some adduction.

The acceleration phase begins at approximately shoulder level and

continues until contact is made with the golf ball. On the left side, there is substantial

muscular activity in the pectoralis major, latissimus dorsi, and sub scapularis as the arm

is extended and maintained in internal rotation. On the right side, there is even more

activity from these same three muscles as the arm is brought vigorously downward.

Once the ball is hit, the follow-through phase begins. Here, there is

continued movement of the arm and club across the body to the left. This movement

must be decelerated and slowed. In the follow-through phase, there is some minimal

activity from the supraspinatus and the deltoid on the right side as the arm moves up

and across the body. The left side has high activity in the subscapularis, and moderate

activity in the pectoralis major, latissimus dorsi, and the infraspinatus as the upward

movement to the arm is curtailed and slowed. It is here in the follow-through phase

that considerable strain can be placed on the posterior portion of the right shoulders

and the anterior portion of the left shoulders as the rapid deceleration occurs (30).

In 1986 Jobe, Perry, Pink (31) compares the electromyographic firing

patterns of normal shoulders musculature in men and women professional golfers.

Eight shoulder muscles (pectoralis major, latissimus dorsi,.supraspinatus, infraspinatus,

subscapularis, anterior, middle and posterior deltoids) were studied using indwelling

electromyography. A visual analysis revealed that women tended to have slightly moreCopyright by Mahidol University


activity during the takeaway and forward swing phases, and the men tended to have

more activity during acceleration and followthrough. However, an independent two-

tailed t-test (P:0.05) showed these differences not to be statistically significant.

In 1982 Jobe, Moynes, Antonelli (32) the swings of seven adult male

right-handed professional golfers without shoulders problems were examined.

Indwelling electrodes were inserted into the supraspinatus, subscapularis, infraspinatus,

Iatissimus dorsi, pectoralis major, anterior deltoids, middle deltoid, and posterior

deltoid on the right side. Results indicate that all portions of the deltoid were inactive

on the right side throughout the swing. The deltoid was likewise inactive on the left

except for a brief spurt from the anterior portion during the milliseconds immediately

preceding ball contact. Of the rotator cuff muscles, on the left the supraspinatus fired

at a low level through the swing, as did the infraspinatus. The latter had a slightly

larger burst of activity immediately after ball contact. The subscapularis was more

active than any other muscle throuhout the swing. The cuff muscles on the right side

showed as much activity overall as those on the left. In addition, the latissimus dorsi

and pectoralis major seemed to provide power bilaterally, with marked activity during

the acceleration phase.

In1992 Kao, Pink, Jobe, Perry (33) studied 15 competitive male golfers.

Four muscles were studied bilaterally using dynamic electromyography and

cinematography. In the trailing arm, the levator scapulae elevate while the rhomboid

muscles retract the scapula during takeaway; both then stabilize the scapula throughCopyright by Mahidol University

Pornthep Rachnaly Review Literature / 44

the remainder ofthe swing ln the leading allll,theSe muscles retract the scapula during

forward swing and acceleration The trapezius muscle in the trailing arm also

demonstrates high activity du五 ng takeaway to aid in scapular retraction ln the leading

arm,trapezius acti、aty is high in fonvard swing and through the remainder ofthe swing

to promote scapular retraction The serratus anterior muscle activity is high in the

trailing allll duHng fonvard swlng and through the remainder ofthe svnng to lnaxirnize

scapular protraction.. In the leading allll, the Serratus anteriOr muscle has constant

activity through au phases ofthe swing The golf swing and uncoiling actiOn requires

that the scapular muscles work in synchrony to ma刈nlize swing arc and clubhead

speed. This study demonstrates the importance of the scapular muscles in the golf

swing and the need for speciflc strengthening exercises

In 1996 Watkins, Uppal, Perry, et al (34) using dynamic surface electrode

electromyograpy evaluated muscle activity in 13 male professional golfers during the

golf swing. Surface electrodes were used to record the level of muscle activity in the

right abdominal oblique, left abdominal oblique, right gluteus maximus, left gluteus

maximus, right erector spinae, left erector spinae, upper rectus abdominis, and lower

rectus abdominis muscle during swing. The findings demonstrate the importance of the

trunk muscles in stabilizing and controlling the loading response for maximal power

and accuracy the golfer's swing.

In 1994 Bechler, Jobe, Pink, Perry (35) described the electromyographttc

(EMG) muscle activity of the shoulders, back, and trunk during the golf swing. SixteenCopyright by Mahidol University

Fac ofGrad.Studies Mahidol【」niv l\4.Sc.(Spon Science) / 45

golfers were studied with indrvelling electrodes and high-speed cinematography. The

results revealed that the trail hips extensors and abductors in conjunction with the lead

adductor magnus initiated pelvic rotation during forward sw1ng. The lead hamstrings

rnaintained a flexed knee and provided a stable lrase on rvhich pelvic rotation took

place. The peak EMG muscle activity recorded in the hips and knees occured in an

earlier phase than that measured previously in the trunk and shoulders. This confirmed

the sequential firing pattern of the hips and knees muscles tliat takes place during the

competitive gol f swi n-q.

ln 1992 Pink, Perry, Jobe (36) describe and conrpare the muscle firing patterns

in the trunk during the golf swing. Twenty-tluee golfei's u,ith handdicaps of five or

below volunteered for the study. Surface eiectromi'ographic electrodes were placed on

the abdominal oblique and erector spinae muscies bilaterally. The results demonstrated

relatively low activity in all muscles during takeau,ay (below 30oh ofmaximal muscle

test). and relatively high and constant activity throughout the rest of the swing (above

30olo rnaximal muscle test, with the exception of the contralateral erector spinae during

late follow-through, which was 28%io maximal niuscle test). This high and constant

activity demonstrated the importance of the trunk muscles during a golf swing.

In 1999 Pink. Jobe,Perry (37) analyze the EMG activitli in eight shoulders

muscles of both the right and left arms during golf su,,ing. 'I'he results reveal that the

infraspinatus and supraspinatus act predominanLl5, at the extrernes of shoulders range

of motion, the subscapularis and pectoralis major during acceleration. the latissimus


Pornthep Rachnavy biew Litcrature/46

of motion, the subscapularis and pectoralis major during acceleration, the latissimus

dorsi during forward swing, and the anterior deltoid during forward swing and follow-

through. The middle and posterior deltoids appear to be relatively noncontributory,

without any specific timing patterns.

{


”■

［

Fac.of Grad Studes,Mahidol U面v M.Sc.(Sport Science) / 47

CHAPTER IⅡ

METHODS

Subject

Twenty males right hand club golfer, with a mean of age, height, weight, arm

segment, trunk segment, upper leg, lower leg, hand grip, flexibility and handicap

respectively, volunteered to participate in the study. Ten were short golferr'urd tm

were height golfers with average handicap of 9. The golfer carried out 20 tee shot. All

subjects were requested to sign informed consent forms prior to participation.

Instrumentation

Collecting Data

1. Two video cameras @anasonic)

2. Two sets of camera tripod (Manfrotto 0558)

3. Two video recorder @anasonic NV-SD320)

4.Event & Video control unit (Peak Performance Technologies)

5. Time code (florita SR-50)

6. Cassette tape @anasonic)

7 .Two set of monitor (Fujiyama CA 688)

8. Sixteen adhesive circular marker

9. Golf iron (sand wedge and 3-iron)

10. Calibration frame with25 control points.Copyright by Mahidol University

-- ---

Pornthep Rachnavy Mcthod/48

Analyze Data

l. Videocassette Recorder (Panasonic AG-7350)

2. Panasonic color video monitor @T-Sl-460Y)

3. Personal computer with motion analysis solfirare (Peak Motus

2000)

Data Collection

The subjects were taken anthopometric parameter measurements, of arm

segment, body segment, upper leg segment, lower leg segment. The physical

characteristics of age, height, weight, flexibility and hand grip strength of all subject

were measured. The subjects_ were instructed to wore short sleeved shirts and short

trousers in order to avoid disrupting their preparation and swing. Distal end of right

and left feet, ankles joints, knees, hips, shoulders joint centers were identified by

marking the skin or clothing above a specified landmark.

Filming took place on the driving range, about 250 meters long. Prior to their

testing session, subjects were carefully instructed in the study protocol. Markers were

placed on the head vertex at the C-7, as well as the bilateral wrist, elbows, shoulders,

hips, knees, ankles and toe. Each stroke was filmed using two synchronized Panasonic

video cameras operating at 50 fields per second, each with a shutter setting of 1/500

second. They were placed in the same horizontal plane and aligned. so that their optical

axes at approximately 60 degree@igure 1). The cameras were positioned 10 meters

away from the subject, in front of and to their left. The golfer performed each stroke

within the 1.9 x 1.6 x 2.2 meters volume defined by a calibration frame containing 25

'(i.


Fac of Grad Studies,Mahidol Univ. M.Sc.(Sport Science) / 49

point of known location according to the procedures set by the Peak performance

technologies Inc. This calibration frame was filmed prior to each subject's testing.

After a warn up period, each subject hit ten golf ball off practice mat using sand

wedge and ten golf ball using iron No 3

The cameras were started approximately 3 second priors to the beginning of

each shot to ensure that they reached full running speed. Event synchronization was

achieved by manually activated switch prior to drive. This placed a mark on the film in

both cameras at identical times, thus ensuring that frames could be matched for

subsequent analysis. The cameras were not switched off until finished the follow

through to ensure a recording of a sufficient portion of the performance. The three-

dimensional coordinates of each digitized point were smoothed and the first derivative

obtained from gener alized cross-validate Butterworth. The cameras were used with

electronic ll5OO second shutters in order to give a sharp image of rapidly moving body

segment

. As the motion of the club throughout impact occurs at a very short time

interval, it would be necessary to use high speed cameras to study its motion in detail.

However, as this study was concerned with the relatively low speed motion of hand

rotation, it was considered appropriate to use cameras operating at 50 fields per

second. This procedure has been used in a number of studies involving activities which

have a high speed of movement


Pornthep Rachnavy Method/50

Figure 4 Camera position

Data Reduction and Analysis

Means of the three longest drive with each club of each subjects in the

direction of the flag were chosen for further analysis, as these were thought to be the

representatives of the technique associated with their best stroke. All fields from both

videotapes of each drive were digitized,between the address and the end of the follow

through, of the same operator using @eak performance technologies Inc.)

The following points were digitized. vertex of head; 7th cervical vertebra;

right and left glenohumeral, elbow, wrist, hips, knees and ankle joint; distal end of the

right and left feet. The following segments were defined (defining anatomical

Iandmarks in parentheses); head/neck (vertex of head, 7th cervical vertebra); trunk

(right/left glenohumeral joint, elbow joint); right/left upper arm (glenohumeral joint,

elbow joint); right/left forearm (elbow joint, wrist joint); right/left hand (wrist joint, 3rd

metacarpophalangeal joint ); right/left thigh (hips joint, knees joint); right/left calf

Toし b08

:.60 degrcC


Fac of Grad Studes,ヽ lattdol Umv M.Sc.(Sport Science) / 5l

(knee joint, ankle joint); right/left foot (ankle joint, distal end of foot). Definitions of

the measured joint are as follows:

Shoulders: the three-dimensional included angle formed by a line joining the

centers of the shoulders joints and the appropriate elbow joint

Knees: the three-dimensional included angle formed by a line joining the hips,

knees and anklesjoint centers

Ankles: the three-dimensional included angle formed by a line joining the

knees and anklejoint centers, and the distal end ofthe foot.

Hip. the three-dimensional included angle formed by a line joining the trunk

and thigh joint centers

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Figure 5 Joint angles

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Pornthep Rachnavy

Statistical Analysis

Method/52

Statistical analyses were performed with the SPSS 7.5 for Window. Data

were expressed as mean * standard error of mean (SEM) values. Paired t-test and

independent t-test were used to assess in the variables. Two-tailed t-tests were used to

assess the peak hand velocity, as different between sand wedge and iron No 3, and use

to assess the angle between sand wedge and iron No 3, as different between sand

wedge and iron No 3, and use to assess the angles of short and tall golfers, as no

different befween short and tall golfers during address with sand wedge and iron No 3

The mean of three longest drive of each club of each golfer in the direction of

the flag were chosen for further analysis, as this was thought to be representative of

the technique associated with his best strokes. All fields from both videotapes of each

drive were digitized, between the address and the end of the follow through, by the

same operator using (Peak Motus 2000). The three-dimensional coordinates of each

digitized point were smoothed and first derivative obtained from generalized cross-

validated Butterworth The software package used for digitizatioq three-dimensional

reconstruction and smoothing was implemented for the (Peak performance technology

Inc.) microcomputer.


Fac.of Grad Studics,Mttdol Univ M.Sc.(Sport Science) / 53

Experimental protocol

Health status screened by means of questionnaire and physical

examrnatron

Procedures explained and subjects signed consent

Tall group

Subject preparation

Change into a pair of shorts and sleeves shirtWeight and height measured

Markers placed

Functional leg length measured

Familiarized to the testWarm up


Pornthep Rachnary Rcsult/54

CHAPTER IV

RESULTS

The result of this study were concerned with the joint angles of ankles, knees,

hips and shoulders of golfers at address position between sand wedge and iron No 3,

comparison of peak hand velocity during downswing between sand wedge and iron No

3 and comparison joint angles of ankles, knees, hips and shoulders between short and

tall groups.

The result section of comparison was divided into four parts as following

topics

1. The general characteristics and physical fitness characteristics

2. Compaison of peak hand velocity of short and tall groups during swing

with sand wedge and iron No 3.

3. Comparison of the joint angles of ankles, knees, hips and shoulders at

address position between sand wedge and iron No 3 of short and tallgroups.

4. Comparison of the joint angles of ankles, knees, hips and shoulders at

address position between short and tall groups of sand wedge and iron No 3.


Fac of Grad Studes,Mttdol Univ M.Sc.(Sport Science) / 55

1. The General Physical Characteristics and Physical Fitness

Characteristics

1.1 General Physical Characteristics

Twenty male golfers participated in this study. Ten were short groups

and ten were tall group. Age and general physical characteristics of the subjects in

both group are show as mean t SEM in Table 6. There were no significant difference

in age. However, there were significant differences in height between the two groups

of subjects (p < 0.05).

Table 6 shows the age of short group (37.6!3.53) and tall group (36+

2.95). The age of short and tall group were not significantly different. The height of

short group (167 510.60) and tall group (174.1+1.18) were significantly differentt

from each other. The weight of short group (65.15!2.55) and tall group (74.45t3.18)

were also significantly differentt from each other.

Table 6 Anthropometric data: age, height and weight.

Group Age (years) Height (cm) weight (kg)

Short group 37.6±3.53 167.5± 0.60 65。 15± 2.55

Tall group 36±±2.95 174。 1± 1。 18 74。 45± 3.18

Significance NS S S

Values are means + SEM. Levels of statiStical significance refer to difference between

the mean values for short group and tall group.

【●′


Pornthep Rachnavy Result/56

1.2 Physical Fitness Characteristics

The mean +SEM value of physical fitness characteristics of short and tall

subject are presented in Table 7 . Arm segment lengh of short group (74.75+0 69) and

tall group (77 89!0 88) were significantly differentt. The same as the trunk segment

length (41.75t0.97) and (44.63fi.93) for short and tall group, respectively, and upper

leg segment length (49.05+0 67) and (51.8311 0) for short and tall group, respectively.

However, the lower leg segment of short group (45.45+0.30) and the tall group

(43.37+0.69) were not significantly different. The same as the flexibility of short group

(012.30) and the tall group (0.7!2.27) and hand grip strength of short group (43.3!

1.74) and the tall group (47 .9!2.69).

Table 7 Body segment and physical characteristic data: arm, trunk, upper leg, lower

leg, flexibility and hand grip.

Segment Short group Tall group significance

Arm (cm) 74.75± 0.69 77.89± 0。88 S

Trunk (cm) 41.75± 0。97 44.63± 0.93 S

Upper Leg (cm) 49.05± 0.67 51.83± 1.0 S

Lower Leg (cm) 45.45± 0.30 46.37± 0.69 NS

Flexibility (cm) 0± 2。30 0.7± 2.27 NS

Handgrip (kg) 43.3± 1.74 47.9± 2.69 NS

Values are means + SEM. Levels of statistical significance refer to difference between

the mean values for short groups and tall group.Copyright by Mahidol University

Fac.ofOrad.Studies,Mahidol UШv M.Sc.(Sport Science) / 57

2. Comparison of Peak Hand Velocity of Short and Tall Group during

Swing with Sand Wedge and lron No 3

Summaries of mean and (tSEM) of peak hand velocity for both short and tall

group are presented in Table 8 and Fig 6-13 . The average peak hand velocity value of

short group for sand wedge was (8.58+0.57) m/s, for iron No 3 (8.92+0.66) rnls,

whereas the peak hand velocity value of tall group for sand wedge was (8.31+067)

m/s, for iron No3 (8.97+0.63)m/s. The paired t-test showed that the mean peak hand

velocity of sand wedge of short group were not significant differences (p>0 05) from

the mean of iron No 3. No significant difference of the above parameters were found

between sand wedge and iron No 3 of all group for peak hand velocity.

Table 8. Peak hand velocity between sand wedge and iron No 3 in the group

Group Sand wedge

(m/s)

Iron No3

(m/s)

Significance

Short group 8.58± 0.57 8.92± 0.66 NS

Tall group 8.31± 0。67 8.97± 0.63 NS


the mean values for short groups and tall group.


Pornthep Rachnavy

Figure 6 Average peak hand velocity of sand wedge in short group

Figure 7 Average peak hand velocity of sand wedge in tall group

Result/58

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Fac of Grad Studies,Mand01 u血v M.Sc.(Sport Science) / 59

SHORT GRO■ IP TALL GRO■ IP

Figure 8 Average peak hand velocity of sand wedge in short and tall group

Figure 9 Comparison of peak hand velocity between sand wedge and iron No 3 in

short group


Pornthep Rachnavy

Figure 10 Average peak hand velocity of iron No 3 in short group

Figure 11 Average peak hand velocity of iron No 3 in tall group

Result/60

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Fac of Grad Stu“ es,Mahdol univ M.Sc.(Sport Science) / 61

SHORT GRO■IP TALL GRO■ IP

Figure 12 Average peak hand velocity of iron No 3 in short and tall group

Figure 13 Comparison of peak hand velocity between sand wedge and iron No 3 in tall

group.

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Pornthep Rachnayy Remt/62

3. Comparison of the Joint Angles of Ankles, Knees, Hips and

Shoulders at Address Position between Sand Wedge and Iron No 3

of Short and Tall Group

The result of this section are shown in Table 9, l0 and Fig 14,15 with the

presentation of mean and (ISEM). The paired t-test reveal that the mean value of

ankles, knees, hips and shoulders were significantly differentt at (p>0.05) when

compare between sand wedge and iron No 3 in short group. Moreover, the tall group

demonstrated a significant differences of ankles, knees, hips and shoulders when

compare sand wedge and iron No 3.


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Fac of Grad Studies,Mahidol Ul五 v M.Sc.(Sport Science) / 63

Table 9. Comparison of ankle angles, knee angles, hip angles and shoulder angles

between sand wedge and iron No 3 in short group.

Joint angles Sand Wedge

@egree)

Iron No 3

(Degree)

Significance

Left Ankles Angle 7631±044 81.46±078 S

Left Knees 144.14±070 14891±059 S

Left Hips 129.28±0.76 13185±059 S

Left Shoulders 32.48±029 3426±057 S

Right Ankles Angle 7641±041 81.68± 093 S

Right Knees 14418± 062 14875±057 S

Right Hips 12948± 0.78 131.60±062 S

Right Shoulders 31.93±0.37 3389±0.54 S


the mean values for sand wedge u* ,.on No 3.



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Figure 14 Joint angles of ankle angles, knee angles, hip angles and shoulder angles at

address position between sand wedge and iron No 3 in short group.

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Fac.of Grad Studies,M」巨dol Univ M.Sc.(Sport Science) / 65

Table 10. Comparison of ankle angles, knee angles, hip angles and shoulder angles

between sand wedge and iron No 3 in tall group.


the mean values for sand wedge and iron No 3.

ｏ」　

　

　

〓

Joint segment Sand Wedge(Deeree)

Iron No 3(Desree)

Significance

Left Ankles Angle 7706±051 8146±079 S

Left Knees 14491±064 14976± 0.51 S

Left Hips 12936±067 13296± 1 15 S

Left Shoulders 3171±038 33.24± 054 S

Right Ankles Angle 76.96± 039 8121±074 S

Right Knees 14506±068 149.53± 046 S

Right Hips 12956±069 13293± 119 S

Right Shoulders 3152±041 3311±051 S



Figure 15 Joint angles of ankles angle, knees angle, hips angle and shoulders angle at

address position between sand wedge and iron No 3 in tall group.

4. Comparisons of the Joint Angles of Ankles, Knees, Hips and

Shoulders at Address Position between Short and Tall Group of

Sand Wedge and Iron No 3

Mean values and (tSEM) of average ankles, knees, hips and shoulders joint

angles at address position between short and tall group of sand wedge and iron No 3

are presented in Table ll, 12 and Fig 76,17. The unpaired t-test showed that the mean

of all joint angles of sand were not significant differences (p>Ct05) when compare

between short and tall group, while the mean of all joint angles of iron No 3 were also

not significant differences (p>0.05) when compare between short and tall group.

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Fac of Grad Studcs,Mahidol Un市 . M.Sc.(Sport Science) / 67

Table 11. Comparison of the ankles angle, knees angle, hips angle and shoulders angle

at address position by using sand wedge between short and tall group.


the mean values for short group and tall group.

ｏ　　　　　ヽ日

Joint segment Short Group(Deeree)

Tall Group(Deeree)

Significance

Left Ankles Angle 7631±0.44 77.06±051 NS

Left Knees 144.14±070 14492±064 NS

Left Hips 12928± 0.76 12936±067 NS

Left Shoulders 3248±029 3071± 0.38 NS

Right Ankles Angle 7641±041 7696±040 NS

Right Knees 14419±062 14506±068 NS

Right Hips 12948±078 12956±069 NS

Right Shoulders 3193±0.37 3153± 041 NS

・■・　　　　　　ヽ・



Figure 16 Joint angles of ankles angle, knees angle, hips angle and shoulders angle at

address position using sand wedge between short group and tall group.

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Fac of Grad Studies,Mahidol U面 v M.Sc.(Sport Science) / 69

Table 12 Comparison of ankles angle, knees angle, hips angle and shoulders angle at

address position by using irons No 3 between short and tall group.

Joint segment Short Group(Deeree)

Tall Group(Deeree)

Significance

Left Ankles Angle 8146±078 8146±0.79 NS

Left Knees 14891± 0_59 14976±0.57 NS

Left Hips 13185±059 13296± 115 NS

Left Shoulders 3426±057 3324±054 NS

Right Ankles Angle 81.68± 093 8121±074 NS

Right Knees 14875± 0.57 14953±046 NS

Right Hips 13160±062 132.93± 119 NS

Right Shoulders 3389±054 3311±051 NS

Values are means t SEM. Levels of statistical significance refer to difference between

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Figure 17 Joint angles of ankle angles, knee angles, hip angles and shoulder angles at

address position using iron No 3 between short group and tall group.

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Fac.of Grad Studes,Mahidol U血v M.Sc.(Sport Science) / 71

CHAPTER V

DISCUSSION

Comparison of Angles between Sand Wedge and Iron No 3

The main purpose of this study was to compare the joint angles at address

position between sand wedge and iron No 3. Paired t-test between mean joint angles of

ankles, knees, hips and shoulders at address position with sand wedge and iron No 3

indicate a significant differences for all joint angles. The results were in close

agreement with the finding of other studies involving joint angles at address position

with different iron.

Brennan (3) study the joint angles with difference clubs (Pitching wedge,

Driver, S-iron) he found that at address position with short iron, the joint angles were

smaller than long iron.

The different in joint angles appeared to be related to club lengh and lie

angles. Golf clubs were produced in only one standard length. The driver was longer

than the 3-iron, and the 3-iron was longer than the wedge. Lie refers to the angles of

club as it leaves the shaft. Long clubs always have a flatter lie than short clubs (9).

In this study, the results also strongly support the findings that the joint angles

at address position with long iron were greater joint angles when compare with the

short iron. Since the short iron were shorter in club length and lie angles than those in

Iong iron, and these two factors are important determinants ofjoint angles.

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Pornthep Rachnavy

Comparison of Angles between Short and Tall Group

Result/72

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?'This study provide preliminary data relative to joint angles of ankles, knees,

hips and shoulders at address position between short and tall golfers. From literature

review, there was no research comparing the joint angles at address position between

short and tall golfers The results in this study demonstrate that there were no

significant differences in joint angle of ankles, knees, hips, and shoulders at address

position befween short group and tall group. There are a few possible explanation for

this results, First ,each subject, during address position, require the balance for

swinging the club. The second factor were lie angle and club length

At address position, the golfer would adjust their position for the optimum

balance by flex their joint angles to relation with the length and lie angle of the clubs.

Therefore, in address position the balance is importance. The joint angles of ankles,

knees, hips and shoulders should relate to the length and lie angle of the clubs.

Comparison of Peak Hand Velocity

To our knowledge, this is the first published prospective study designed to

investigated the effects ofjoint angles of ankles, knees, hips and shoulders at address

position on development of peak hand velocity in golf swing. It has been established

that there is reason to believe that the musculature about the ankles, knees, hips and

shoulders joint could be directly related to peak hand velocity in golf swing.

From a biomechanical perspective of muscle about length-tension relation

ships state that "The amount of maximum isometric tension a muscle is capable of


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Fac of Grad Studies,Mahidol U血 v M.Sc.(Sport Science) / 73

isolated muscle preparations, fOrce generation is at its peak when the muscle is at

nollllal resting length(neither stretched nor contracted)When the length ofthe muscle

increases or decreases beyond resting length, the maxirnum force the muscle can

produce decreases,fonowing the forrn ofa bd卜 shaped curve"(4)

Within the human body,however,force generation capability increases when

the muscle is slightly stretched.Paranel_■ bered muscles produce maxilnunl tensions at

just Over resting length,and pennate-lbered muscles generate ma刈 mum tensions at

between 120%and 130%of resung length(5)This phenOmenon is due to the

contHbution of the elastic components of lnuscle,which add to the tension present in

the muscle when the muscle is stretched.Research indicates that following eccentHc

exercise there may be a slight,transient increase in muscle length that impairs force

developrnent whenjoint angle does nOt place the muscle in sufEcient stretch(6).

According to this theory, dinbrence should e対 st in peak hand velocity value

obtained between both irons since the length of muscle at address position was

di」匿じrence However, the results of this study showed that there were no signiflcant

dittbrence of peak hand velocity between sand wedge and iron No 3 These would

mean that duHng swlng with dinbrentiron,the hand velocity was similarly.

To increase the peak hand velocity ofthe golf swing the co― Ordination ofthe

movement of dinbrent body segments is necessary to transfer to the maxllnum The

kinetic link p五 nciple is an important factor in increasing the pe」 (hand velocity This

pHnciple conceptualizes an e3bctive strokc as one which is initiated by large muscle

groups acting on large body segments with the purpose of storing signiflcant rotational

and translational kinetic energy.

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Central to this principle is the conservation of angular momentum as the

momentum is transferred from one segment of the chain to the next. More specifically,

as the proximal segment moves through its mid range of movement, and approaches its

final range, the angular velocity of this segment reaches a peak. After this point

deceleration occurs and the angular velocity decreases causing angular momentum to

decrease. It is at this point that the attached distal segment experiences acceleration

and its angular momentum actually increases. In this way angular momentum is not

being lost, but transferred from the proximal to the attached distal segment.

The linear velocity of any point on a rotating segment is directly proportional

to both its angular velocity and its radius of rotation. Linear velocity of the more distal

segments will be greater than the proximal segment. Not only will the angular velocity

be greater but the radius of motion will also have increased. This too, therefore, will

contribute to attaining maximum velocity of the hand velocity.

In the golf swing, the kinetic link is composed of four segments with three

link. These four components and three links combine to create the body system. The

components consist of the hips segment, shoulders segment, arrns segment and the

club. The links include the musculature found between each body segment.

The body uses the motion of the back swing may be thought of as the counter

movement. As the swing progresses, the movement transitions from stretch to shorten.

At this point, the legs act as pistons creating torque on the hips or pelvis. The action

stops the lower body from moving in the clockwise direction of the back swing and

accelerates it in the counterclockwise direction of the down swing. The upper torso,

however, continues to move in a clockwise direction enhancing the action of the

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Fac of Grad Studics,Mahidol U血 v M.Sc.(Sport Science) / 75

stretch-shorten loading. Shortly after the muscles of the torso begin to stretch the

shoulders the lower body, the shoulders segment begins to accelerate in a

counterclockwise direction. Transition occurs in a coordinated fashion between each

segment until all body segments are accelerating in a counterclockwise direction.

The muscles that have been stretched in a coordinated fashion now start to

shorten in coordinated fashion. The muscles of the trunk of torso which make up the

first link between the hips segment and the shoulders segment are the first to shorten.

As they shorten, the hips segment is decelerated. Similar to the snapping towel

example, the deceleration of the hips segment creates lost mass to the system and

facilitates the conservation of momentum from the larger base segment of the hips to

the smaller adjacent shoulders segment. The result is a large increase in the speed of

the shoulders segment. Just as this occurs, the muscles of the second link between the

shoulders segment and the anns segment shorten. The shortening decelerates the

shoulders segment, which in turn facilitates the conservation of momentum between

the shoulders segment and arms segment. The arns segment experiences a large

increase in speed. Finally, the same action occurs between the arms segment and the

club. The end result is large increase in velocity and a maximum linear and angular club

head speed through impact.

Timing is the only one possible explanation for this results. Timing is a term

use to denote synchrony or coordination. Internal timing is the coordination of

muscular contractions to produce smooth, rhythmic movement. It is this quality that

allows forces of individual segments to be summed up in such a way that the velocity

of the fist, for example, is much faster than the contributed from arm extension alone.

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Pornthep Rachnavy Rcsult/76

Body segments are coordinated so that the positive velocity of the center of gravity,

hips rotation velocity, shoulders protraction velocity, and the linear velocity of the fist

, due to forearm extension are accelerated when the preceding segment in the chain is at

its peak velocity to produce this efflect.

External timing simply refers to the coordination of movement of one system,

' such as a person, with another to meet a certain purpose. For example, correct timing

is said to have taken place when a person counterattacks at an adversary's weakest

position in a technique (7).

Limitation

In this investigation, a number of characteristics of subject sample may have

limited the fndings and contributed to large standard deviation observed in result.

Characteristic such as body composition, muscle strength/endurance, exercise habits of

subject used were not controlled. Combinations of these sample characteristics.may

have influenced the out come of the above result.

Further Research

The present study represents the first examination in peak hand velocity in

Thai subjects. Further studies should include women golfer. Further studies may also

consider height difference of subject in more detail.

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Fac of Grad Studies,Mahidol U面 v M. Sc.(Sport Science) / 77

CHAPTER VI

CONCLUSION

From the studies of peak hand velocity of different height golfer of different

angles at address position between sand wedge and iron No 3 in Thai single handicap

golfer by 3D analysis. The conclusion of the result were

1. Peak hand velocity in short group between sand wedge and iron No 3.

There is no significant different at the p<0.05 level. It mean that in short iron (sand

wedge) and long iron (iron No 3) which there is different long shaft and total weight

not affect to peak hand velocity in short group

2. Angle of ankles, knees, hips and shoulders in short group between sand

wedge and iron No 3 show that there is significant different at the p<0.05 level. It

mean that in short iron (sand wedge) and long iron (iron No 3) which there is different

in long shaft and lie angle affect to angle of segment at address position in short group

3. Peak hand velocity in tall group between sand wedge and iron No 3. There

is no significant different at the p<0 05 level. It mean that in shoft iron (sand wedge)

and long iron (iron No 3) which there is different long shaft and total weight not affect

to peak hand velocity in tall group.

4. Angle of ankles, knees, hips and shoulders in tall group between sahd

wedge and iron No 3 show that there is significant different at the p<0.05 level. It may

mean that in short iron (sand wedge) and long iron (iron No 3) which there is different

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Pornthep Rachnavy Conclusion / 78

in long shaft and lie angle may affect to angle of segment at address position in tall

group

5. Angles of ankles, knees, hips and shoulders between short group in sand

wedge. There is no significant different. It may mean that angle in short and tall group

at address position they setup the same posture may be for balance.

6. Angles of ankles, knees, hips and shoulders between short group in iron No

3ron. There is no significant different. It may mean that above angle in short and tall

group at address position at the same posture may be for balance.

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REFFERENCE

1.Dedc Owen,Linda K.Bunker.Advance golf step to success.11linois:Leisure Press;

r992

2. james Richards, Martin Farrell, James Kent, Robert Kraft. Weight transfer patterns

during the golf su,ing. J RQES 1985; 56(a): 36i-365.

3. Brennan L. J.. A comparative analysis of golf drive and seven iron with emphasis

on pelvic and spinal rotation [Ph.D. dissertation]. University of Wisconsin

Madison; 1968

4. Chapman AE.. The mechanical properties of hunran ntuscle. Exerc Sport Sci Rev

1985; 13:443.

5. Gowitzke BA., Milner M.. Understanding the scientific bases of human movement.

t 2 nd ed.Baltimore: williams & wilkins; 1980.

L

: 6 Saxton JM, Konnelly AE. Length-specific, impairment of skeletal muscle contractile

b' function after eccentric muscle actions in tnan. Clin Sci 1996;90: I 19.

7 Marion R Broer. Efficiency of human movement. 2,nd ed. Philadelphia: Saunders;

1996.

8 Marlene J. Adrian, John M. Cooper. Biomechanics of human movement. 2nd ed.

Boston: WCB McGraw-Hilt; 1995.

9 Broer. Ir4, Houtz. S. Patterns of muscular activin, in selected sports skills. Spring

field II: charles C. Thomes: 1967 -

l0 A. Garth Fisher, John Geertsen. Jr. Golf your tum for success. Jones & Bartlett

４ヽ、　　し、咆

■・ｔヽ」 Publishers:1991


Pornthep Rachnary References / 80

l H」 am∝ GHり .The Ыom∝ha血面叩orts t∝ hiquぃ■だ ed New■ttey

晋 Prentice Hall;1985.

12.D.Williarn.The science ofthe golfswingo London:Pelllan Books Ltd;1969.

13.S.Carlsooo A kinetic analysis ofthe golf swing J sports nledicine and physical

fltness 196717:80-81.

14.Cochran A,Stobbs J.The search fbr the pcrfect s、 villg.Philadelphia:Lippincottp;

1968.

妥' 15 Bunn,John W.scientinc principles ofcOchin3.Ne、 v YorkI Prentice hall book

compan)'Inc:1955

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与番

　ヽヽす

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Fac.ofGrad Studies, Mahidol univ M.Sc.(Sport Science) / 83

APPENDIX

PⅡYSICAL EXAMINA■ ON FROM

Name

Age ….… .… ….…・… … … …・… _ Sex

Wdght …… …… …… Kg Height .... cm.

Handicap

Segment Lengths

Thigh Lengths

Calf Lengths

Am Lengths

Trunk Lengths

Muscle Strength

Hand Grip .

基,

ヽム盛■Ｔ，

ヽ当

Cm

kg

Fle対bility Cm

i===二[=二こ

=======r‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐

1====「■■=‐

‐‐‐‐‐■F‐==‐

‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐、


Pomthep Rachnavy

BIOGRAPHY

NAME

DATE OF BIRTH

PLACE OF BIRTH

INSTITUTION ATTENDED

Biography / 84

N4r. Pornthep Rachnavy

6 March 1970

Udonrthanee, Thailand

Malridol University, 199l-1992 :

Bachelor of Science (Sport

Science)

Mahidol University, 1999-2001 :

Master of Science (Sport Science :

Biomechanics)

』ヽ」を■

津


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