Designing Healthy Work Environments Vanessa del Aguila, M.Sc. AEP Associate Ergonomist Humanscale Corporation.

Designing Healthy Work Environments

Vanessa del Aguila, M.Sc. AEPAssociate ErgonomistHumanscale Corporation

• Understanding of current workplace trends

• Definition of ergonomics and common misconceptions

• Identification of musculoskeletal risk factors

• Essential ergonomic concepts

• Key elements of an ergonomic workstation

LEARNING OBJECTIVESdesigning healthy work environments

• The workplace is getting smaller; average square footage per worker has decreased by 17% since 1994

WORKPLACEtrends

“I think there is a world market for maybe 5 computers.”- Thomas Watson, Chairman, IBM, 1943

• Our workforce is aging; by the year 2015, 50% of the US population will be 40 or older

• Vision issues continue to be among the most common musculoskeletal complaints

• Laptop computers have become increasingly popular

• Home computing is compounding exposure to musculoskeletal risk factors

THE STAGGERING COSTof lost productivity

• Survey randomly sampled 28,902 working adults

• A total of 52.7% of the workforce reported having headache, backache, back pain, or other musculoskeletal pain

• Average lost productive time was 5.2 hours per week

• Costs associated with common pain conditions and lost productivity in the U.S. is estimated at $61.2 billion per year

Source: Stewart, W., et al. ‘Lost productive time and cost due to common pain conditions in the US workforce’, Journal of the American Medical Association, 290(18), 2003.

• This workstation looks good but will not accommodate all

• Individual differences have not yet been addressed

• What is likely to happen next?

IS THISan ergonomically designed workstation?

• Employees respond to discomfort through workstation modification.

• Your design vision is disrupted every time a work environment is reconfigured for productivity and comfort

WHATis driving the need for these accessories?

• Employees redesign their workstations to compensate for poor design

• What kind of work experience is this organization providing to this employee?

HOWdoes this happen?

• Health, comfort and performance are moderated by design

• The job is not complete until individual differences are considered

• Workstations can be aesthetically pleasing and functional at the same time

DESIGNto accommodate individual differences

Office ergonomics applies science to workplace design to maximize worker productivity while reducing operator fatigue, discomfort and injury.

HOW DOES ERGONOMICSaddress these issues?

MINIMIZEawkward postures

Minimize postures that require excessive muscle activity to maintain and tax the musculoskeletal system.

MAXIMIZEneutral postures

Maximize your time spent in neutral postures that require minimal muscle activity to maintain

BREAKold habits

Installing equipment does not necessarily solve postural problems

Elevate your awareness of your posture throughout the day

KEY ELEMENTSof an ergonomic workstation

1) The chair

2) The keyboard and mouse

3) Monitor and document

placement

4) Proper Lighting

1970s CHAIRS

• No controls• No adjustability

• Too many manual controls• Adjustability not used

1980s and 1990s CHAIRS

chair adjustmentsESSENTIAL CHAIR ADJUSTMENTS:

• Seat height

Ergonomic chairs should offer adjustable:

• Seat depth

• Backrest / lumbar height

• Armrests

Traditional Armrests Synchronous armrests move together

• Recline tension

Recline Tension

• Adjust the recline tension to

support your body weight

• The backrest should move

freely and support you

throughout the recline range

ESSENTIAL CHAIR ADJUSTMENTS:


1) The chair



placement

4) Proper Lighting

ANATOMYof the wrist

EFFECT OF WRIST EXTENSION ANGLE

Source: Weir, P, Wells, R. ‘The effect of typing posture on wrist extensor muscle loading’, Human Factors, 44(3), 2002.

on intracarpal tunnel pressure

• Wrist extension angle, intracarpal tunnel pressure, and wrist extensor muscle activity are directly correlated

• 30 degrees of wrist extension correlates to a 27.5% increase in forearm muscle activity and greater than a two-fold increase in intracarpal tunnel pressure

A decade of ergonomics research shows that using a negatively sloped, adjustable keyboard tray maximizes the time spent working in neutral hand, wrist and upper body postures. These postural benefits can’t be achieved by just using a keyboard on a height adjustable work surface

- Dr. Alan Hedge, Cornell University

RECONSIDERkeyboard and mouse position

• Positioned hands in a neutral posture 62% of the time compared with 42% for the traditional KB position

• Predicted carpal tunnel pressure remained below the critical threshold 82% of the time compared with 48% for traditional KB position

• Significant improvements in upper body comfort found for shoulders, upper arms, neck and back

• 91% of those using the tray said it helped their work performance and preferred it to their previous system

ARTICULATING KEYBOARDtray research findings, Hedge, 1995

MOUSING“The use of a computer mouse is not necessarily benign. Evidence is

accumulating that computer mouse use is associated with a number of

upper extremity musculoskeletal disorders.”

– Dr. Alan Hedge, Cornell Universitychallenges

Postural Risk Factors:

• Wrist Anchoring

• Wrist Extension

• Ulnar/Radial Deviation

• Over-pronation

Design Challenges:

• One size does not fit all

• Most designs do not

accommodate left handed users

DESIGN APPLICATION:to minimize wrist extension and contact stress


1) The chair



placement

4) Proper Lighting

MONITORand document placement

The top line of text on the monitor should be at or slightly below eye level and at an arms reach

The monitor and any documents for copy should be placed directly inline with the keyboard to minimize neck and trunk rotation

MULTIPLE MONITORdilemma

• As monitor width increases, our viewing envelope is compromised

• As a result, monitors must be positioned further away, which can negatively effect our ability to view the screen

• Users prefer a viewing distance of 75-83cm; minimum distance is 40cm

MULTIPLE MONITORarrangement

Primary and Secondary Screens

• If a single screen is used for more than 70% of tasks, orient the primary monitor with the midline of the body

• Place secondary monitor adjacent, angled inward toward user

MULTIPLE MONITORarrangement

Two Screens, ‘Equal’ Usage

• If any single monitor is used between 40% - 60% of the day align the center of both monitors with the midline of the body. Angle screens inwards

FLAT PANEL MONITORfacts and considerations

Flat panel monitors consume 60% less energy and emit 80% less heat than traditional CRT monitors

Workstations designed with flat panel monitor technology can be 10-20% smaller and maintain the same usable work surface area

The reclaimed space afforded by FPM’s is unusable unless the monitor is mounted on an adjustable arm

Courtesy of Architecture

Magazine, June 2003

Neutral Reach Zone

Courtesy of Architecture

Magazine, June 2003

Neutral Reach Zone


1) The chair



placement

4) Proper Lighting

RECONSIDERexisting lighting strategies

Single source lighting schemes are inappropriate for accommodating today’s range of computer users

THE MONITOR/DOCUMENT CONFLICT

• Monitors generate light, while paper reflects light

• Reading paper-based documents requires 4-5 times more light than does viewing a monitor

LIGHTING REQUIREMENTS

Relative Contrast Required as a Function of Age

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100

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20-30 31-40 41-50 51-60 61-70

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• The need for task lighting increases with age

• Persons ages 61-70 require more than 250% more contrast than persons ages 20-30

• Task visibility is the primary aspect of lighting that affects performance

60 Years

Contrast requirements increase exponentially after age 40.

75 Years20 Years

CONTRAST REQUIREMENTSas a function of age

Single component:

• Too much light above eyes• High energy waste

Dual component:

• Light level determined by user• 30-40% less energy required

BENEFITSof a dual component lighting scheme

RECONSIDER THE USE OFUnder-Bin-Lighting

Under-Bin-Lighting:

• Provides lighting away from where the tasks are actually occurring!

• Does not offer individual control of illumination level

• Is less energy efficient than most controllable task lights

Potential source of glare Light is away from where work is occurring

RECONSIDER THE USE OFunder-bin-lighting

ECONOMICS OFimproved lighting technologies

• Dual component lighting schemes can reduce energy consumption by one third compared to conventional lighting systems

• A task and ambient lighting system is effective in reducing energy consumption because ambient illumination levels can be decreased while task illumination levels can be increased

Comparison of energy consumption, before and after refurbishment

Source: Akashi Y, Mukal K, Yanabe Y. A task and ambient lighting system providing

energy efficient savings without decreasing the overall brightness impression

“Appropriate rest breaks, combined with stretching exercises, allow computer workers to sustain work at an appropriate pace, while minimizing postural injury risk.”

– Alan Hedge, Cornell University

ENCOURAGE

• Proper rest breaks allow the

body to recover from repetitive

stress

• Changing tasks is also

beneficial

• 2-3 short rest breaks are

recommended per hour

micro breaks

ECONOMICS OF ERGONOMICSsuccess stories of ergonomic implementations

American Express • Within four years claims dropped 80% from

$484,000 in year 1 to $98,000 in year 5

AT&T Global• Decline in lost workdays from 298 before

implementation to 0 in the first two years • Claims dropped 75% from $400,000 to

$94,000 in first year• Savings of $1.48 million

Source: GAO/HEHS-97-163 ‘Private Sector Ergonomics Programs Yield Positive Results’

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FOUR KEY POINTSto remember about ergonomics

1. Ergonomics is a preventative, design based discipline

2. Ergonomic interventions can benefit the masses, not

just those that are injured

3. Product interventions alone are not enough – training is

an integral part of an ergonomic program’s success

4. See ergonomics as a benefit to an organization, not as

a burden!

Thank you for your time!

Questions?

Vanessa del Aguila, M.Sc. AEP

E-mail: [email protected]

Phone: 347.277.0153

Designing Healthy Work Environments Vanessa del Aguila, M.Sc. AEP Associate Ergonomist Humanscale Corporation.

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