LIFE2014

OS3-2

2014 年 9 月 24
2 日－26 日 北海海道

身体体バランスの視点かららみた腰部部サポートウェアの効効果
An Innfluence onn Human Po
ostural Balaance of Waiist Support Wear durinng Lifting Loads
L○ 丁憙勇 （阪大）清水木戸咲希（阪大大）渡辺倫
倫子（阪大）野野村宗一
一郎（鴻池運運輸）鳥飼 一男（鴻池運一運輸）林泰伸（（阪大）三善英知（阪大大）山田憲嗣
嗣（阪大）大大野雅信
信（鴻池運輸輸）

ゆう子（阪大）Hieyoong JEONG1, Saki SHIMIZ
ZU1, Soichiro WATANABE
E2, Kazuo TORIGAI2, Massanobu HAYA
ASHI2,1
1
11M
Michiko KIDO , Taishin NOMURAN,EEiji MIYOSHII , Kenji YAM
MADA , and Y
Yuko OHNO11
OSSAKA Univerrsity
2
KONOIKKE Transport Co., LTD.
Abbstract: We hhave an intereest in the relaationship betw
ween the hum
man postural balanceband bback injuries. Although baack
inju
uries are the nnumber-one problem
pfacing the workforrce in the indu
ustry of carrying loads, theere appears to be no firm iddea
on how this willl deal with in practice. In thist paper, wee focus on evaaluating how the human poostural balancce is affected bythee waist suppoort wear. We measure the center of baalance during lifting loads with or withhout the waisst support weear
we found thee influence on
acccording to thee time scheduule. Through experiments,ew
n human postuural balance ofo waist support
weear. Namely, thhe center of balancebis enhhanced under the conditionn of waist support. And wee can see that the tendency ofsubbject for centter of balancee gets to be similar to thaat of expert byb using the support weaar. We show and discuss thetexp
perimental meethod and resuults.
oads, Nintendo wii balancee board, Centeer of balance
Keey Words: Huuman posturall balance, Waist support weear, Lifting lo
1. INTRODUCTION
In the induustry of carrrying loads, the number ofpattients with baack injuries haas been increaasing every yyear.
It isi well knownn that the amoount of weight you lift and thewaay you carry aand move it playpa big rolee in preventinng abacck injury, beccause the hum
man body is not designedd toliftt heavy loadss [1]. Thus, a lot of healtth service cennter
sug
ggest that cerrtain actions area more likely to cause bback
inju
uries than othher, accordinggly anytime youy find your self
doiing one of thhese things; heavy
hlifting,, twisting at thewaaist, reachingg and lifting,, and workinng in awkwaard,
unccomfortable ppositions. How
wever, as the result of Burreauof Labor Statisstics in USA
A is shown, more than oone
milllion workerss suffer back injuries eachh year, and bback
inju
uries accountt for one of everyefive wo
orkplace injurries.
This means thatt material hanndling and liffting injuries areexcceedingly paiinful, difficullt to heal, andd have an eff
ffecton everything yyou do [2]. Although
Abackk injuries are thenum
mber-one prooblem facing the workforce in the indusstryof carrying loadds, there appears to be no firm
fidea on hhow
this will deal w
with in practicce. At this point, we startt tohav
ve a questionn about the different posssible factor forevaaluating the mmotion carryinng loads [3 ~ 6].
Focusing onn the role of brain,b
the goal of this papeer isto evaluate an innfluence on thhe human postural balancee ofwaaist support w
wear during liffting a load ass shown in Figg.1.
Acccordingly, w
we focus on evaluating howhthe humman
posstural balance is affectedd by the waist support w
wear
witth the functioon of power support.
sNamely, We meassurethee center of baalance during lifting loads with or withhoutthee waist suppoort wear accorrding to the timetschedulee. A
subbject lifts an object as usuual. While a subject standd up
by lifting loadss, the result ofo this experiiment shows thecen
nter of balancce during liftinng a load. Thrrough all of

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Fig
g. 1. An experiimental overviiew for measu
uring the centeer ofballance during lifting a load.

expperiments, wee found that tthe trace of centercof balaanceis enhanced
ewheen a subject w
wear the waist support.
2. EXPEERIMENT
Fig. 1 sho
ows the totaal experimen
ntal system forevaaluating the balance. TThe system consists of theNin
ntendo Wii balance board and the computer. The booard
usees Bluetooth technology and contain
ns four presssure
sennsors that arre used to mmeasure the user’su
centerr ofballance. The computercis used to gett data from theballance board throughtBlueetooth, and th
hen process data
dforr calculating thet center of balance [7]. Fig. 2 shows thefloow chart for all of expeeriments. At first, a subjject
perrforms to lift loads from 6 kg to 18 kg withoutw
the waistw
suppport wear [8], and thenn does same things with thewaaist support wear.
w
For deeciding the steadysstate, thesubbject makes a stop during ffive seconds while measurring
thee center of ballance. All of subjects are 20
2 ~ 40 years old,thrree males withhout any physsical handicapp.
Fig. 3 show
ws the experim
mental resultts of beginner atthee weight of 18
8 kg. In this ppaper, a begin
nner indicates theLIFE2014

2014 年 9 月 24
2 日－26 日 北海
海道Fig
g. 3. The exp
perimental reesults of beg
ginner under theconndition of waisst support weaar.

Fig. 2. The experiimental flow chhart.

maan not to carrry loads for living. Fig. 3 (a) represeents
undder the norm
mal conditionn, and Fig. 3 (b) represeents
undder the conndition withh the waist support w ear,resspectively. Thhe point of (0, 0) meanns the centerr ofballance for staanding state asa initializatiion. Althoughh a
subbject has any swing motionn during liftinng a load withhoutthee waist suppoort wear, wee can see thaat the centerr ofballance is enhaanced under the conditionn with the w
waist
suppport wear. TThe subject allso has the feeeling for pow
wersuppport.
As a result, we confirmedd the influencce on the humman
posstural balance of waist suupport wear during liftinng aloaad.
3. DISCCUSSIONFig. 4 shows the experim
mental results of expert at theweeight of 18 kgg. In this papeer, an expert inndicates the mman
to carry loads ffor living. Fig. 4 (a) repreesents under thenorrmal conditioon, and Fig. 4 (b) repreesents under theWeconndition with the waist suppport wear, respectively.
rcann see that ann expert doessn’t have a bigb enhancem
mentwitth the waist support weaar because heh has the goood
exp
perimental reesults withoutt the support wear originaally.
Hoowever, when you comparee the results ofo Fig. 3 (b) w
withthee results of Fiig. 4 (a), youu can see that the tendencyy ofbeg
ginner for thhe center of balancebis similar to thatt ofexp
pert. This inflluence comess from the waist support w ear.
The waist suppoort wear helpp a subject too lift a load w
withsomme power suppport. The poower support comes from thelenngth change oof elastic mateerial, namely, elastic restorringforrce. Through all of experriments, we canc see that theelaastic restoringg force is usseful for the human postuuralballance.

Figg. 4. The ex
xperimental rresults of ex
xpert under thecon
ndition of waisst support weaar.

suppport wear acccording to thhe time scheddule. Throughh allof experiments by using Ninntendo Wii baalance board, wecon
nfirmed the innfluence on th
the human postural balancee of
waaist support wearw
during lifting a loadd. And then theten
ndency of beginner for thhe trace of ceenter of balaancegetts to be simiilar to that oof expert by using the waist
wsuppport wear.
REFER
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http://uhs.berkeley.edu/facstaff/erggonomics/lifting/saafelifting.shtml(2)

G. Beaudette, “Material Hanndling and Back Safety Trainiing,”
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H. Jeong, S. Shimizu, S. Wat
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PLoS,

Publiished

online,doi:

10.1371/journnal.pone.00629566, vol.22, no.5, e62956,
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4. CONC
CLUSION
We evaluatee how the human postural balancee isafffected by the w
waist supportt wear. We meeasure the cennterof balance durinng lifting loadds with or without the waisst

Health Servic
ces Tang Center,, Berkeley University of Califorrnia,

nshield and R.A
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Wii Balance Board,B
http://en.wiikipedia.org/wiki/W
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rakunie, http:///www.morita1199.com/study/heallth/rakunie.html

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