MRIで評価したテニス肘用バンドの有効性

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Report

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23

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8

Il7507

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511

_R'

₍₁₉₉₆

_Hi)

Use

of

the

Forearm

Support

Band

for

Tennis

Players

Examined

by

Magnetic

Resonance

Imaging*

Toru

NoboruOGINOi'

2'

_3),

Hiroo

IKEHIRAi'

3),

_Hideshige

_MORIYA2),

ARIMIZUi),

Koichi

WAKIMOTO`),

Teruhiko

HAYASHI`},

Satoru

NISHIKAWA2),

Hirotoshi

KAT03>,

Fumio

SHISHID03),

and

Yukio

TATEN03)

Abstract

There

are

tennis

_players

who

feel

some

_pain

of

their

_proximal

forearm.

The

symp-tom

is

called "tennis elbow".

It

is

thought

that

the

extensor carpi radialis

brevis

muscle

(ECRB)

is

related

to

the

mechanisrn of

the

tennis

elbow and

the

forearm

sup-port

band

is

effective

to

the

tennis

elbow,

Then

we examined whether

ECRB

was related

to

the

_pain

when swinging

the

racket and

hitting

the

ball

or not, using mag-netic resonance

imaging

(MRI).

ECRB

_got

high

signal

intensity

in

the

image

due

to

their

muscle edema.

Next

we examined

if

the

forearm

support

band

was effective

in

which swinging

the

racket

(concentric

contraction of

ECRB)

_or

hitting

the

ball

(ec-centric contraction) as

the

band

_prevented

increase

of

the

signal

intensity,

The

band

protected

the

muscle edema more

_effectively

in

hitting

_the

ball

_than

in

swing-ing

the

racket, as

the

defined

_effective

ratio

[ER]

of eccentric contraction

(O,79)

was smaller

than

that

of concentric contraction

(1.01).

Key

words

Forearm

support

band,

Tennis

elbow,

Magnetic

resonance

imaging

Introduction

Physical

exercise

induces

an

increase

in

.1)2)3]

4}

MRI

T

_stfi

L

lt

j== x

fistM.W

FofiM,tr

Departrnent

of

Radiology,

University

of

Chiba

Department

of

Orthopaedics,

University

of

Chiba

Division of Clinical Research, National Institute of

Radiological Sciences Funabashi Orthopaedics

Correspondence

to:

Toru

Ogino

(Present:

Watanabe

Hospital,

1-4-23

Nishikicho,

Fuji-shi,

Shizuoka

417,

Japan){Received

July

25,1994fAccepted

September

7,1996)

blood

flow

to

the

skeletal muscle

involved.

Sirnultaneously,

there

is

an

increase

in

the

permeability

of muscle capillary vessels

which

in

turn

increases

both

extracellular and

intracellular

water componentsi).

Active

and

inactive

muscles

can

be

clearly

distin-guished

in

magnetic resonance

imaging

(MRI)

because

of a

difference

in

water

con-tent

after exercise.

Submaximal

exer ¢

ise

Japanese Physical Therapy Association

NII-Electronic Library Service

JapanesePhysical Therapy Association

sos

_mp7twza\

muscle,

_primarily

in

the

extracellular space, while severe

exercise

leads

to

an

increase

in

intracellular

water2'4),

It

has

been

shown

that

muscle

blood

fiow

is

closely related

to

the

oxygen

demand

of

the

exercising

muscles,

The

hyperemia

at

low

work

in-tensities

is

due

to

vasodilatation, while

the

elevated mean arterial

blood

pressure

only

con-tributes

to

the

linear

increase

in

fiow

at

high

work rates5).

Signal

intensity

of

T2

weighted

gradient

echo

MRI

is

directly

related

to

tissue

water content6).

This

has

been

shown

to

be

true

for

skeletal muscles7),

Froimson

has

designed

a

forearm

support

band

which was

inelastic,

_providing

a simple method of achieving

this

desired

relief of

tension8)

(Fig.

1).

Burton

has

demonstrated

an

increase

in

the

_pain-free

_grip

strengths

in

85%

of

27

epicQndylitis

_patients

with

the

use of a

forearm

support

band9),

The

exact mechanism

by

which

the

forearm

support

band

decrease

the

symptoms of

tennis

elbow

has

not

been

shown,

The

purpose

of

this

study

is

to

rnake clear

which

muscles

was

mostly

concerned

in

play-ing

tennis

and

how

the

support

band

is

useful

in

_protecting

muscles against

their

damages.

Fig.1.

Tennisplayer

wearing

forearm

support

band

showing correct

level

of application.

ee

23

tseg

8

e

Materials

and

Methods

Eight

young

male vQ,lunteers

were

sub-jected

to

two

methods of

_physical

exercisep,

Before

exercise,

MRI

at rest was obtained of

proxirnal

one

fourth

of

the

right

forearm.

The

subjects were

_positioned

_prone

in

the

magnet, with

their

right arm

_positioned

in

the

center

of

a

saddle

shaped

head

coil.

The

head

coil was

30

cm

in

diameter,

had

a

200

mm

field

of view, a

10mm

thickness

and a

256

×

256

matrix.

A

gradient

echo scanning sequence was used

(TR!TE

==

50e

_msec/30

msec,

flip

angle

30e)iO).

This

T2

weighted

MRI

provided

increased

contrast and

had

shorter scanning

time

than

any other

gradi-ent echo or spin echo

technique

in

our

trial.

The

resulting scan

time

was

3.5min.

The

MR

machine

in

this

study was a

Philips

Gyroscan

S15/HP

equipped with a

supercon-ductive

and

horizontal-bore

magnet,

operat-ing

at

1.5

Tesla,

First,

we

examined

what

muscle

was

most

related

to

the

pain

when swinging

the

racket and

hitting

the

ball,

using

MRL

The

first

method

of

exercise was

to

grip

a

tennis

racket with

the

right

hand

and

hit

a suspended

_gum

ball

by

a

forehand

swing.

This

was

_performed

for

a

_period

of

20min

when

they

had

been

exhausted.

The

right

forearm

was

then

scanned

immediately

after

the

exercise as a

described

above.

Ad-ditionally,

the

same manner

by

a

backhand

swing was

_performed.

Secondly,

we examined whether

the

fore-arm support

band

was effectiye

in

which s'winging

the

racket

(concentric

contraction of

ECRB>

or

hitting

the

ball

_(eccentric

con-traction)

as

the

band

prevented

increase

of

Use

of

the

Forearm

Support

Band

for

Tepnis

Players

Examined

by

Magnetic

Resonance

Imaging

protocol

consisted

of

controlled

eccentric

and

concentric contraction of wrist extensors.

With

the

elbow

joint

extended and

the

fore-arm

_pronated,

a weight of

2kg

was

sus-pended

from

the

hand

at

the

level

of

meta-carpophalanx-

joints,

In

this

_position

the

extensor carpi radialis

brevis

and

longus

muscle

(ECRB

and

ECRL)

are attheir maxi-mum resting

length.

Concentric

exercise was

accomplishied

by

lifting

the

weight

10cm

upwards one

time

every second,

for

2min

while

they

were enough exhausted,

The

forearm

was

scanned

immediately

after

exer-cise.

Eccentric

exercise was

_performed

by

having

an assistant

lifted

the

weight

10cm

upwards and

having

the

subject

lower

the

weight at a constant rate.

Interval

of a week was allowed

between

exercises.

The

concen-tric

and eccentric exercise were repeated with a

forearm

support

band

in

_place,

and

the

arms appropriately scanned.

The

signals obtained after concentric or ec-centric contraction of

the

ECRB

and

ECRL

509

were

analyzed with respect

to

the

signal of

flexor

carpi radialis muscle

(FCR).

The

FCR's

consistently

low

signal makes

it

an excellent reference marker.

One

region of

interest

(ROI)

was selected within

ECRB

(ROI-1)

and one within

FCR

(ROI-2).

These

measured

1.0

cm2 round

<Fig.

3).

The

ratio of signal

inten-sity

(SI)

of

ROI-1

to

ROI-2,

which

is

ab-breviated

as

[R],

is

defined

below.

(SI

of

ROI-1

after

exercise/SI

of

ROI-2

after exercise)

!

(SI

of

ROI-1

at rest!SI of

ROI-2

at rest)

The

effective ratio

[ER]

was

defined

as

the

ratio

of

[R]

with

the

forearm

band

with

re-spect

to

[R]

without

the

forearm

band.

Results

In

the

first

method of exercise,

both

ECRB

and

ECRL

demonstrated

higher

signal

in-tensities

after swinging

both

forehand

(left,

Fig.

2>

and

backhand

(right,

Fig.

2).

The

FCR

consistently

demonstrated

low

signal

in-tensities.

We

understood

_that

ECRB

and

ECRL

muscle

_group

was most related

to

the

Fig.

2.Axial

MRI

of

the

proximal

forearm

after swinging a tennis racket.

Both

the extensor carpi radialis

brevis

and

longus

muscles

(ECRB

and

ECRL)

demonstfated

higher

signal

intensities

after swinging

forehand

(left)

and

backhand

(right).

The

flexor

carpi

Japanese Physical Therapy Association

NII-Electronic Library Service

JapanesePhysical Therapy Association

510

Fig.

3.

-e}f:wh2kt}..ee

23

igee

8

-"s

Two

regions of

interest

(ROI)

were selected

(ECRB)

and within

flexor

carpi radialis muscle rest

(left),

after exercise with

the

support

band

(righO.

'

pain

when swinging

the

racket and

hitting

the

ball.

In

the

second method of exercise,

the

effec-tive

ratio

[ER]

was

defined

as

the

ratio of

[R]

with

the

forearm

band

with respect

to

[R]

without

the

forearm

band.

The

average

[ER]

was

1.01

±

O.09

{mean

±

SD,

n=8)

for

concentric contraction, while

the

average

[ER]

was

O.79

±

O.10

(mean

±

SD,

n==8)

for

ec-centric exercise

trials.

The

effective ratio of

eccetric

contraction

was

significantly

smaller

than

that

in

concentric contraction

(p<O.OO1)

by

unpaired

t-tesO

_(Fig.

3).

Discussion

It

is

generally

thought

that

many

_patients

with

tennis

elbow

had

micro

tears

of

the

ECRB

at

its

attachment

to

the

lateral

epicondyleii].

The

ECRB

is

found

to

arise not solely

from

the

lateral

epicondyle

but

also

the

capsule of

the

elbow

joint

and associated

ligament.

Contraction

of muscle

is

likely

to

exert unequal

tension

on related soft

tissues,

and may'be

the

_principal

factor

in

the

development

of

injury

at

this

site.

The

attachrnents of

ECRL

do

not

tear

as

they

are

tt,ttttt

within extensor carpi radialis

brevis

muscle

(FCR).

These

are

images

of same

forearm

at

(center),

and after exercise without

the

band

wide and elastici2).

An

injured

muscle will show a significant

increase

in

water content,

It

follows,

there-fore,

that

any

intervention

that

decreases

muscle

damage

should

decrease

that

muscle's signal

intensity

in

T2

weighted

MRI,

This

study

has

shown

that

the

forearm

support

band･should

be

more useful as

band

effec-tively

decrease

thc

signal seen

in

the

ECRB

after eccentric

_exercise

(the

effective ratio was

O.79).

The

support

band

was not as effective

in

decreasing

injury

during

concen-tric

contraction

(the

ratio was

1,Ol),

When

the

forearm

support

band

is

_placed

on

the

proximal

forcarm,

inflammation

of

the

ECRB

after eccentric contraction

is

reduced.

Active

eccentric muscle contraction of

the

wrist extensors

is

frequently

seen

during

the

follow

through

of

the

tennis

stroke.

We

sug-gest

that

the

forearm

support

band

can

be

useful

for

tennis

players

by

decreasing

in-flammation

and associated

damage

to

the

ECRB

during

ecccntric contraction

(i.e.

Use

　of　

the

　

Forearm

　

Support

　

Band

　

for

　

Tennis

　

Players

　

Examined

　

by

　

Magnetic

　

Resonance

　

Imaging



511

Acknowledgments

　

This

　work 　

is

　

supported

　

in

　

part

　

by

　

grants

　

of

Ministry

　of　

Welfare

　and 　

Special

　

Coordination

Funds



of



the



Science



and



Technology

Agency

　of　

the

　

Japanese

　

Government ，

References

1

）

Berldstrup

　

P

：

Late

　edema 　after 　muscular 　exer

．

　 cise

．

　

Arch

　

Phys

　

Med

　

43

：

401

−

405

，

1962

．

2

）

Sjogaad

　

G

_，　

Saltin

　

B

：

Extra

−

and 　

intracellular

　

water 　spaces 　

in

　muscle 　of　man 　at　rest　and 　

dy・

　 namic 　exercise

．

　

Am

　

J

　

Physiol

　

12

：

R271

−R280，

　

1982

．

3

）

Sjogaad

　

G

：

Electrolytes

　

in

　slow 　and 　

fast

　 皿 uscle　

fibers

　of　

human

　at　rest　with　

dynamic

　 exercise

．

　

Am

　

J

　

Physiol

　

14

：

R25

−

R31

，

1983

．

4

）

Sjogaad

　

G ，

　

Adarns

　

RP ，

　

Saltin

　

B

；

Water

　and 　

iQn

　 shifts　

in

　skeletal　 muscle 　 of　

humans

　with　

in−

　 tense

　

dynamic

　

knee

　extension

，

　

Am

　

J

　

Physiol

　

248

；

R190−Rl96 ，1985．

5

）

Anderson

　

P

，．

Saltin

　

B

：

Maximal

　

perfusion

　of

　

skeletal 　muscle 　

in

　man

．

　

J

　

Physio1366

：

233

−

　

249

，

1985

，

6

）

Meulen

　

P

，

　

Groen

　

JP

，　

Tinus

　

AMC

，

　et　al

．

：

、

　

Fast

　 　

field

　echo 　

imaging

：

An

　overview 　and 　contrast

　 　calculations

．

　

Magn

　

Reson

　

Imaging

　

6

_：

355−368 ，

　 　

1988，

7

）

Ogino

　

T，

　

Ikehira

　

H ，

　

．

Arimizu

　

N ，

　et　al

．

：

Serial

　 　water 　changes 　

in

　

human

　skeletal 　muscles 　on

　 　exercise 　studied 　with 　 _proton 　magnetic 　resひ

　 　nance 　spectroscopy 　and　

imaging．



Annals

　of

　　

Nuclear

　

Medicine

　

8

：

219

−224，1994 ．

8

）

Froimson

　

A

：

Treatment

．

of　

tennis

　elbow 　_with

　 　

forearm

　support

．

band．

　

J

　

Bone

　and 　

Joint

　

Surg

　 　

53

−

A

：

183

−

184

，

1

、

971

．

　　　　　　

、

9

＞

BurtQrl

　

AK

：

Grip

　strength 　and 　

forear

皿 straps

　　

in

　

t6nnis

　elbow

，、

Brit

　

J

　

SpQrts

　

Med

　

19

：

37−

38

，

　 　

1985

．

10

_）

Briggs

　

CA

，　

Elliott

　

BG

：

Lateral

　epicondylitis

− A

　 　review 　of　structures 　 associated with 　

tennis

　 　elbow

．

　

Anat

　

Clin

　

7

_：正

49

−153，1985．

11）Doran 　A

，

　

Gresman

　

GA ，

　

Rushton

　

N

，

　et　al

．

：

　　

Tennis

　elbow

− A

　clinicopathologic 　study 　of

．

22

　 　cases　

followed

　

for

　

2

　_years

．

　

Acta

　

Orthop

　

Scand

　 　

61

：

535

−

538

_，

1990

．

12

_）

Fleckenstein

　

JL，

　

Weatherall

　

PT

，　

Parkey

　

RW

；et

　 　at

．

：

Sports−

related 　muscle 　

injuries

_；

Evaluation

　 　with 　

MR

　

imaging

，

　

Radiology

　

1721793 −798，

　 　

1989．

〈

要

旨

〉

MRI

で

評価

し

た

テニ ス

肘

用バ _{ン ドの}

_有

_効

_性

荻野

　

透

1

’

2

’

3）

_{，池平博夫}

1

’

3） ，

守

屋

秀繁

2） ，

有水

加 藤 博 敏

3），

宍 戸 文 男

3） ，

舘 野

之

男

3） 1）

千

葉

大 学 医 学

部放射線医学教

室

2）

千

葉大学医学部

整

形外科学教

室

3）

放 射 線 医学 研 究 所 臨 床 研

究部

4）

船 橋 整 形 外 科

昇

1） ，

脇

元 幸

一

4）

_，林



輝 彦

4）

，

西 川

　

悟

2）

，

　

テニ ス

_{競 技 を す}

る

際

に

，

前 腕

の

近 位 部

に

疼 痛 を 感

じる

事 が あ り

，

　

こ の

症 状

はテa ス

_{肘 と}

呼

ば れて い る。

短 橈 側 手 根 伸 筋 （

ECRB

）

との

関

連

が

深

い と

言

わ れ

， テニ ス

肘用

バ _{ン ドの}

_装

着

によ

り

，

疼 痛

が

軽 減 す

る。

　我

々は， こ のバ ン ドの

装

着

が

本

当

に

有効

なのか ど う か を

立 証 す

る た めに

7

名

の

健 常 男 子

を 被 験 者 と

して

実 験 を

行

っ た。

作

動

した

骨 格 筋

が

血 流

の

増 加 と

と もに

浮

腫

を

起

こ し

磁

気共

鳴画

像

（

MRI ）

に て

_白

く

高信号

を呈 す

る

事

を

利

用

し た。 その

結果

， ラケ ッ トの

素振

り

動作

と

ボ

ー

ル

を 打

つ

動 作

の

両 方

で

ECRB

は

高 信 号 を 呈 し浮 腫 を 起

こ

し

て いた。 そこで， バ ン ド を

装着

して

類 似

の

動

作

を

負

荷

してみる と

，

ボ

ー

ル を

打

つ

_{動 作}

の

時

には

浮 腫

を

約

80

％

に

抑

え る

事

が わ か

り

，

バ ン ドの

_装着

が

有効

で

あ

ると

考

え ら れ た。