injury & ergonomics risk factor

8/8/2019 Injury & Ergonomics Risk Factor

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Present by : Mohamad Ikhwan (M9801807)

Final Project - Applied Ergonomics ClassNTUST Summer 2010

Instructor : Prof Chia-Fen CHI


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Ergonomics is the study of the physical and cognitivedemands of work to ensure a safe and productive

workplaceThe goal of ergonomics is to keep the demands of the

job within the physical and cognitive capabilities of employees.

E nvironmentE nvironmentTask/jobTask/job

Worker Worker

The goal of ergonomics is to design theThe goal of ergonomics is to design the job to fit the worker job to fit the worker

NOTNOT make the worker fit the jobmake the worker fit the job


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FatiguePain

Illness sprains, back ache, etcINJURIESLow mo raleFrustrati o n & Irritati o n

P oo r Quality AbsenteeismHigher c o stsHigher empl o yee turn ov er &training

And why do we need it?And why do we need it?

Injury (als o bodily injury o r bodily harm ) is damage o r harm caused t o the structure o r functi o n o f the bo dy caused by an o utside agent o r f o rce , w hichmay be physical o r chemical , and either by accident o r intenti o nal. Pers o nal Injuryals o refers t o damage caused t o the reputati o n o f an o ther rather than physicalharm t o the b o dy. A se v ere and life-threatening injury is referred t o as a physical

trauma (WIKIPEDIA) .


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Higher pr o ducti v ityHigher QualityReduced o perat o r injuryIncreased m o raleGreater j o b satisfacti o nLow er medical & insurance c o stsReduced l o st timeLow er absenteeismL

ess emplo

yee turnov

er


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Direct Injury - instantane o us (e v ent dri v en )acute injuries happened immediately due t o ov erl o adx sharp pain immediately after lifting hea v y equipmentx injury after tripping ov er rebar and falling

Indirect Injurychronic injuries happened overtime.Cumulative Trauma Disorders (CTDs) exposuredriven, difficult to curex back pain fr o m lifting c o ncrete h o ses daily f o r se v eral

m o nths/yearsx numbness in the hand fr o m years o f o perating p ow er

too ls


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Acti v ity perf o rmed frequentlyYo u d o the acti v ity a l o ng timethe durati o n o f exp o sure gets l o nger the wo rk intensity increases

there are a co mbinati o n o f risk fact o rs


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Fatigue

Disc o mf o rt

Pain

Injury

DisabilityTime

Co ntinued

expo

sure to

risk fact o rs


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C umulative Trauma Disorders ( C TDs )Injury to soft tissue caused by prolonged exposure tomultiple ergonomic risk factorsTypically develop in small body segments (i.e.fingers, wrists, elbows, and neck )

Examples of C TDsTendon disorders:

x Inflammation of tendon and/or tendon sheathing causedby repeated rubbing against ligaments, bone, etc.

x Lateral epicondylitis (tennis elbow )Nerve disorders:

x C ompression of nerves from repeated or sustainedexposure to sharp edges, bones, ligaments, and/ortendons

x C arpal tunnel syndromeNeurovascular disorders:

x C ompression of blood vessels and/or nerves fromrepeated exposure to vibration or cold temperatures

x Raynauds phenomenon (white finger syndrome )


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1. Awkward Postures2. High Hand Force3. Highly Repetitive

Motion4. Repeated Impact5. Heavy, Frequent or

Awkward Lifting6. High Vibration7. Eye Strain


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Awkward postures refer to positions of the body (limbs, joints,back) that deviate significantly from the neutral position while

job tasks are being performed.Being in these work positions for more than 2 hours total per

day:Hands ab ov e headElb ow ab ov e sh o ulder Back bent f o r w ard m o re than 30 degreesNeck bent m o re than 30 degrees

SquattingKneeling

Wo rking in a w kw ard p o stures increases the am o unt o f f o rceneeded t o acc o mplish an exerti o n. A w kw ard p o stures createco nditio ns w here the transfer o f pow er fr o m the muscles t o the

skeletal system is inefficient .


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Neck or Back Bent ForwardMore than 30

For more than 2 hours per day

EXAMP L ES :


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Squatting or KneelingFor more than 2 hours per day


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W orking with the HandsOverhead

For more than 2 hours per day


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MinimizeMinimizeAwkward PosturesAwkward Postures

Use Neutral Posture at the Computer & Other EquipmentUse Neutral Posture at the Computer & Other Equipment


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Neutral posture:

Back supp o rted by the chair back

Ears, Sh o ulders, Elb ow s, Hips v ertically aligned

Elbow s, hips, knees bent at near-right angles (90 o 105 o )

Feet flat o n the fl oo r o r f oo trest

The basic neutral p o sitio n m o st lab pers o nnel sh o uldutilize a maj o rity o f the time they spend seated at theco mputer o r o ther equipment.

BASIC NEUTRALBASIC NEUTRAL


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Forward tilt posture:

Raise the chair height a fe w inches and tilt the fr o ntdow nw ard slightly (8 o - 10 o )

Back Relief Back Relief

Opens hip angle allow

ing legs to

suppo

rts o me w eight.

Not recommended if yo u ha v e knee o r f oo tpr o blems.

May be used o ccasi o nally thr o ugh o ut the day by m o st pe o ple;but is n o t rec o mmended f o r lo ng peri o ds at a time . Next


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Reclining posture:

Lean back 10 o - 20 o into the chair's backrest and put your feet out in front of you.

Lower Body ReliefLower Body Relief

Opens hip and knee angles to help relaxback muscles and promotes bloodcirculation. Leaning back too far can result in an awkward neck posture.

May be used o ccasi o nally thr o ugh o ut the day by m o st pe o ple; but n o trec o mmended f o r lo ng peri o ds at a time.


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Standing posture:

Pr ov ides biggest change in p o sture

Goo d alternati v e t o pr o lo nged sitting

Can be fatiguing, ha v e chair a v ailable

Pr o p o ne f oo t up o n a l ow f oo trest t o help o ccasi o nallyshift y o ur w eight.

Standing NeutralStanding Neutral

May be used o ccasi o nally thr o ugh o ut the day by m o st pe o ple; but n o trec o mmended f o r lo ng peri o ds at a time.


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Adjust y o ur chair t o achie v e a neutral p o sitio n keep trying, it is an o ng o ingpr o cess!

Fix (o r ha v e fixed) a malfuncti o ning chair

Use a lumbar cushi o n f o r additi o nal supp o rt o r if chair lacks adequate backsupp o rt o r seat is t oo deep

Pad armrests that are hardo

r that hav

e square edgesRem ov e armrests if they c o ntribute t o a w kw ard p o stures

Use a f oo t rest o r keyb o ard platf o rm t o help achie v e neutral p o sitio n if necessary

Minimize AwkwardMinimize Awkward

Body PositionBody Position

Next

Adjust Y o ur Chair


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Ideal Chair Features

1. 5-Caster Base

2. Height adjustability3. Seat depth adjustability either seat slides, back m ov es f o re/aft , o r chair is

a v ailable in numer o us sizes

4. R o unded edge t o the fr o nt o f the seat

5. Backrest adjustability up/d ow n, angle, and flex

6. Armrests are padded and adjustable up/d ow n, in/ o ut and/ o r rem ov able

Next


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Lo cate m o nito r:Directly in fr o nt o f keyb o ard, n o tw isting

neck o r back t o v ie w screen

As far a w ay as p o ssible w here material isstill easily read. Arms length o r m o re isdesirable

To p o f screen at o r slightly bel ow eye le v el;low er if w earing bi/tri-f o cal glasses

At right angle t o ov erhead lights andw ind ow s

Minimize AwkwardMinimize AwkwardBody PosturesBody Postures


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Minimize AwkwardMinimize AwkwardHand & W rist PosturesHand & W rist Postures

Neutral

Aw kw ard

Neutral

Aw kw ard

Aw kw ard

Neutral

Aw kw ard

Neutral


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Proximity Items cl o se en o ugh t o usew hile y o ur elb ow s are aligned bet w een

sh o ulders and hips. N o reaching fr o m thesh o ulder.

Angle Wrists & f o rearms parallel t o thefloo r. No f o rearm o r w rist angle.

Padding - No resting o n hard edges.

Gel w rist rests are helpful.

Minimize AwkwardMinimize AwkwardHand & W rist PosturesHand & W rist Postures


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2. High Hand ForceMo re than 2 h o urs per day o f :

Pinching 2 or morepounds weight or 4or more poundsforce

Gripping 10 or morepounds weight or force


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Other steps to

reduce f o

rces:Avo id resting y o ur w rists against a desk edge

Do no t ov er-fill file dra w ers

On large pr o jects, c o nsider mechanized alternati v es t o manual c o mb-

binding, staplingo

r manual physical tasks that are also

highly repetitiv

e.Fo llow safe lifting practices at all times.

Minimize High ForcesMinimize High Forces

Minimizing a w kw ard p o stures reduces many o f the f o rcesplaced o n y o ur b o dy during c o mputer use.


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A repetitive motion injury is an injury to a part of thebody that is caused by performing the same motion overand over again thereby straining the body partStrain occurs when the body part is called on to workharder, stretch farther, impact more directly or otherwisefunction at a greater level then it is prepared for. Theimmediate impact may be minute, but when it occursrepeatedly the constant straining cause damage.Workers repeat same motion every few seconds for morethan 2 hours per day with:

neckshoulderselbows

wristshands


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Repetiti v e acti v ities are m o st o ften a c o ncern w hen c o mbinedw ith a w kw ard p o sitio ns, high f o rces, o r significant am o unts o f time spent at the acti v ity w itho ut adequate rec ov ery time.

Minimize Repetitive MotionsMinimize Repetitive MotionsRepetiti v e M o tio ns aretho se that are repeatede v ery fe w sec o nds f o r extended peri o ds o f time.


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Steps t o reduce repetiti v e m o tio n:

Utilize technology - pr o grammable h o tkeys, aut o co rrect,vo ice rec o gniti o n, and o ther s o ftw are features reducerepetiti v e keying/m o using.

Mechanize - Use electr o nic staplers, c o llato rs, and o ther too ls f o r large, repetiti v e pr o jects.

Vary tasks Perf o rm repetiti v e tasks in se v eral small timeblo cks rather than all at o nce; perf o rm dissimilar tasks inbet w een.

Vary methods Peri o dically s w itch pr o cess fl ow , s w itchtoo ls, s w itch p o sitio ns, s w itch hands t o perf o rm the sametask.

Minimize Repetitive MotionsMinimize Repetitive Motions


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Trackballs

Vertical m o use

Ro llerm o use,

M inimize Repetitive M otionsM inimize Repetitive M otions A dditional steps to reduce risks from repetitive motion include alternatives to thestandard keyboard and mouse, such as:

Natural or Ergonomic keyboards

Split keyboards


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4. Repeated Impact

Using hands o r knees as ahammer

mo re than 10 times per h o ur mo re than 2 h o urs per day


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S o ft tissue c o mpressi o n(muscles, ner v es & bl oo d v essels)


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Lifting objects more than:75 lbs. o nce/day55 lbs. m o re than ten times/day10 lbs. m o re than tw ice/minute

f o r m o re than 2 h o urs per day

25 lbs. abov

e sho

ulders,bel ow knees, o r at arms lengthf o r m o re than 25 times/day


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S ource: American S ociety of S afety Engineers (A SS E, 2003)

L ifting Injuries Arent Just Due t o Aging

O v erexerti o n in lifting a hea v y o bjectis the m o st frequent single type o f

injury f o

r tho

se under 1 8 resulting inlo st wo rk-time.


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Hea v y lifting

Frequent lifting

Aw kw ard lifting


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This j o b is adding bags o f dry ingredients t o a h o pper in a manufacturing plant.


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This j o b is palletizing t o tes o f small parts in a w areh o use.


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Ab ov e the sh o ulders

Bel ow the knees

At arms length

This j o b is lifting 50-p o und bags o f w etfiberglass in a manufacturing plant


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Reduce the w eight

Increase the w eight

Use mechanical assistanceSlide instead o f lift

Team lifting


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Reducing hea v y liftingTake smaller l o ads at o ne timeUse mechanical assistance - handtrucks, carts,ho ists, c o nv ey o rs

Get help fr o m a c o -wo rker


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Frequent liftingL ifting m o re than 10 lbs.,x m o re than t w ice per minute,x f o r m o re than 2 h o urs per dayUse mechanical assistanceSlide o bjects instead o f lifting themRo tate lifting tasks w ith c o -wo rkers if p o ssible


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Aw kw ard liftingx L ifting m o re than 25 lbs. ab ov e the sh o ulders, bel ow

the knees o r at arms length m o re than 25 times per day

Reducing a w kw ard liftsx St o re items w here y o u wo nt ha v e t o bend o r reach t o

lift themx Use r o lling stairs t o get items d ow n fr o m high shel v es


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Get Close tothe Load

Bend your Knees

- Not your Back!

Safe Lifting PracticesSafe Lifting Practices

Use Large LegMuscles toRise Until

Standing


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VASOSPASTIC, NEUROMUSCU L AR, ARTHRITIC DISORDERS OF THE HANDS ANDUPPER L IMBSCOMPOSITE OF VIBRATION INDUCED SIGNS

AND SYMPTOMS (e.g. NUMBNESS, TING L INGOF THE FINGERS, EPISODIC B L ANCHING OFTHE FINGERS, PAIN, REDUCED GRIPSTRENGTH AND DEXTERITYRAYNAUDS SYNDROME, WHITE FINGER


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Any o ne w ho abs o rb machine v ibrati o n thr o ughtheir hand and arm w hile wo rking a fast m ov inghand t oo l,

Or thr o ugh the butt o ck and the s o les o f the feetw hile riding in o r standing near v ibrating, hea v ymachinery.


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DISCOMFO RT FROM CO LDTING LING , NUMBINGBL A NCHING FING ERSP A IN


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The risk o f injury t o wo rkers can be pre v ented o r minimized by:assessing the risks, including c o nducting v ibrati o n exp o suresur v eys as appr o priate, t o identify risky pr o cesses and/ o r acti v itiesde v elo ping a v ibrati o n p o licy and v ibrati o n management pr o gramimplementing a pr o gram f o r c o nducting regular v ibrati o nsur v eys and c o rrecti v e acti o nsimplementing v ibrati o n c o ntr o l measures in c o nsultati o n w ithwo

rkerspr ov iding management and wo rkers w ith educati o n, training andinf o rmati o n o n v ibrati o n exp o sure, its effects and the need f o r itsco ntr o lpr ov iding regular medical check ups t o exp o sed wo rkers


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Co ntr o l measures t o minimize exp o sure t o v ibrati o n include:treating the v ibrati o n s o urce (i.e. is o late v ibrating plant fr o m itsf o undati o n thr o ugh dampers and springs, redesign o r m o dificati o n)treating the v ibrati o n transmissi o n path (i.e. is o late ducts fr o mstati o nary plant, v ibrati o n dampened seating in l o co m o tiv e cabins)treating the recei v er (i.e. is o late c o ntr o lr oo ms/encl o sures/l o co m o tiv e cabins fr o m v ibrating plant andsurfaces)using t oo ls w ith anti- v ibrati o n handlesmaintaining pr o perly sharpened cutting t oo ls

jo b r o tati o n, t o limit exp o sure t o hand arm v ibrati o n exp o sure t o no m o re than f o ur h o urs per shift and o f w ho le b o dy v ibrati o n t o no m o re than eight h o urs per shiftan adequate plant and equipment maintenance pr o grampers o nal pr o tecti v e equipment (e.g. anti- v ibrati o n gl ov es)using minimum hand grip o n t oo ls c o nsistent w ith safe wo rkpractices


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Dry Burning EyesBlurred Visi o nDelayed F o cusing

Altered C o lo r Percepti o nHeadachesNeck Pain


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Place m o nito r in fr o nt o f yo u,no t o ff at an angle.Set c o ntrast/brightness

reduce glareIncrease/decrease lighting use task lightingCo lo r o r print (black print o nw hite is the best)Dust/Clean Screen.


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Avoid turtlenecking and blinkoften

Move documentholder closer tomonitor Avoid looking to the

side and down


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5 2

OSHA: certain situati o ns create CTD risks:Perf o rming same m o tio n pattern e v ery fe w sec o ndsf o r > 2 h o urs c o ntinu o usly o r 4 h o urs daily.Maintaining unsupp o rted, static/fixed o r a w kw ard

po sture > o ne (1) h o ur c o ntinu o usly o r f o ur (4) h o ursdaily.Fo rceful hand exerti o ns > t wo (2) h o urs daily.Unassisted frequent o r hea v y lifting

Bo

redo

m and mo

no

to

ny

D o you have these risks?


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Watch f o r:

Tingling o r numbness inhandsPain: sharp, dull o r burning

sensati o nStiffness, reduced range o f m o tio n in arms, w rists

Clumsiness, l o ss o f gripstrength o r c oo rdinati o nVisual fatigue, w atery eyes,dryness.


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Stage Oneaches and tiredness during wo rking h o urs

sympt o ms settle ov ernight o r days o ff wo rk

no reducti o n in wo rk perf o rmance

co nditi o n may persist f o r w eeks o r m o nths and is re v ersible

Stage T wo

sympt o ms start early in wo rk shift and d o nt settle ov ernight

sleep may be disturbed

capacity t o perf o rm repetiti v e wo rk is reduced

co nditi o n usually persists f o r m o nths


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Stage Threesympt o ms persist e v en at restpain o ccurs w ith n o n-repetiti v e m ov ements o f affected areasleep is disturbedpers o n unable t o perf o rm e v en light duties and hasdifficulties w ith o ther manual tasks


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GuidelinesGuidelines: Sh o ulders relaxed/arms cl o se t o bo dy side; safe: Sh o ulders relaxed/arms cl o se t o bo dy side; safe

reaching distance f o r m o use; neutral sittingreaching distance f o r m o use; neutral sittingRight hand o n m o use e v enw hen n o t acti v ely m o using(median ner v e).

L eft lean supp o rting b o dyw eight w ith arm; spine o uto f natural alignmentUlnar ner v e c o mpressi o n(no n-m o using elb ow )Static muscle l o ading: rightsh o ulder abducti o n, w ristextensi o n, flexed left arm


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Disc o mf o rtTeleph o ne Use

Input De v ices(keyb o ard and p o inting)

Task reakso nito r and isi o n

Wo rk StyleWo rk Surface

L apt o pChair

WritingL ighting

Do cument UseL ay o ut

Indiv idual Issues


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Order of adjustments is importantAdjust chair firstThen adjust keyboardFinally, adjust monitor

No single right way to sit


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Plan wo rk t o break up extended peri o ds o f repetiti v e m o tio n tasksUse screen h oo ds o r glare guards t o minimize glareMaintain natural s cur v e o f yo ur spineSupp o rt low er back

Keep feet suppo

rtedo

n floo

r o

r use a f oo

trest


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Table Height: Av erage height o f 27 t o 29 inches ab ov e the fl oo r is rec o mmended.

If table adjusts, set y o ur 90 degree w aist height inyo ur chair, then adjust y o ur table s o that y o ur elb ow makes a 90 degree angle w hen y o ur handsare o n the keyb o ard.


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Elb ow Angle:With hands resting c o mf o rtably at the keyb o ardand y o ur upper arms v ertical, measure the angle

betw

een yo

ur f o

rearm and yo

ur upper arm (elbow

angle).If less than 90 degrees, raise the seat o f yo ur chair.If greater than 90 degrees, l ow er the seat.


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Waist Angle:Elb ow s at 90 degrees, measure the anglebet w een y o ur upper legs and y o ur spine (w aist

angle). This t oo sh o uld be 90 degrees.If less than 80 degrees, y o ur chair may be t oo low and y o ur knees t oo high.Or alter the p o sitio n o f the backrest o r adjust y o ur ow n p o sture.


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Feet:Elb ow s and w aist at 90 degrees, y o ur feet sh o uldrest c o mf o rtably o n the fl oo r.

If they d o nt, adjust y o ur chair and table height.If table isnt adjustable and y o ur feet d o ntco mf o rtably reach the fl oo r, a raised f oo t rest canhelp.


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To increase circulati o n, use exercises w hilein the wo rkplace such as:Bo dy StretchSide BendsUpper B o dy T w ists

Sh o ulder ShrugsFinger StretchWrist StretchThumb StretchFinger Squeezes

These can be d o ne at the start o f a wo rk shift andf o llow ing meal breaks, during wo rk t o releasetensi o n, after pr o lo nged sitting o r standing, andw hen y o u feel stiff.


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Rec o gnize and rep o rtsympt o ms earlyearly ::x Pain is persistent, se v ere o r wo rseningx Pain radiatesx Sympt o ms include numbness o r tinglingx Sympt o ms keep y o u fr o m sleeping at night

Why is it imp o rtant t o rep o rtsympt o ms earlyearly ?x Chr o nic injuries s o metimes lead t o disability,

e v en surgeryx Early treatment m o re successful


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GET INVO LVED IN ERGONOMICSLoo k at j o bs and help identify pr o blemsCo me up w ith s o lutio nsWo rk w ith s o lutio nsTake part in trainingTake resp o nsibility f o r changing the w ay y o u d o yo ur j o bHelp t o make sure eff o rts are successful


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1 Erg o no mics can help y o u o n y o ur j o b

2 Risk fact o rs can be reduced and injuriespre v ented

3 Yo u can help y o ur c o mpany put erg o no micschanges int o place

4 WMSDs can happen in j o bs w ith risk fact o rs

5 Rep o rting sympt o ms earlyearly is imp o rtant


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http://www .erg o no mics. o rg/http://www . m o ntana.edu/ w ellness/ w ehttp://www .c o mcare.g ow .auhttp://www .nio sh.c o mhttp://www .ease-inc.c o m/

http://www

.w

ikipedia.o

rghttp://www .o sha.g ov /S LTC/et oo ls/c o mputer wo rkstati o ns/checklist/html

http://www .o sha.g ov /S LTC/et oo ls/c o mputer wo rstati o ns/ wo rkpr o cess.html

http://www .o sha.g ov /S LTC/et oo ls/c o mputer wo rkstati o ns/p o sitio ns/html

http://www .o sha.g ov /S LTC/et oo ls/c o mputer wo rkstati o ns/ w kstatio n_en v ir o .html


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