LAB # 3 Workstation Design. Outline June 11, 2014 Lab # 3: Workstation Design 2 Introduction. Ergonomic Design. Modern Work Environment. Workstation Design

LAB # 3

Workstation Design

Outline

April 10, 2023Lab # 3: Workstation Design

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Introduction.Ergonomic Design.Modern Work Environment.Workstation Design Guidelines.Ergonomic Computer Workstation.General Tips.

INTRODUCTION

Lab # 3: Workstation Design April 10, 2023

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Workstation Design

Introduction

Ergonomics is a scientific discipline, which is concerned with improving the productivity, health, safety and comfort of people, as well as promoting effective interaction among people, technology and the environment.

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Lab # 3: Workstation Design

Introduction (Cont.)


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Designing for ergonomics requires understanding and consideration of the following: The physical and psychological attributes of the

person or population of people that will perform the job.

The design and arrangement of the workstation furniture, computer hardware, and other workstation accessories.

The tasks required to perform the job. The work environment, including such things as

noise and temperature, also management and organizational methods and constraints.

ERGONOMIC DESIGN


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Workstation Design

Ergonomic Design


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Because people spend up to 90% of their time indoors, and much of it in their workplaces, the physical environment in offices should be carefully designed and managed.

The physical conditions that operators experience are important determinants of satisfaction, comfort, well-being, and effectiveness.

Ergonomic Design (Cont.)

Ergonomic furniture should be designed to facilitate task performance, minimize fatigue and injury by fitting equipment to the body size, strength and range of motion of the user.

Office furnishings, which are generally available, have adjustable components that enable the user to modify the workstation to accommodate different physical dimensions and the requirements of the job. Ergonomically designed furniture can reduce pain and injury, increase productivity, improve morale, and decrease complaints.

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Ergonomic Design (Cont.)

Ergonomics is used in the design of furniture to eliminate: Static or uncomfortable posture. Repetitive motion. Poor access or inadequate clearance and

excessive reach. Display that are difficult to read and understand. Controls that are confusing to operate or require

too much force.

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Ergonomic Design(Cont.)


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Design objectives should support humans to achieve the operational objectives for which they are responsible. There are three goals to consider in human-centered design. Enhance human abilities. Overcome human limitations. Encourage user acceptance.

Ergonomic Design(Cont.)


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To achieve the previous objectives, there are several key elements of ergonomics in the office to consider. Equipment: video display terminals Software design: system design and screen design

for greater usability Workstation design: chairs, work surfaces and

accessories Environment: space planning, use of colors, lighting,

acoustics, air quality and thermal factors Training: preparing workers to deal with technology

MODERN WORK ENVIRONMENT


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Workstation Design

Modern Work Environment


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Changes in modern business practices have considerably changed the way we work in the office.

The delivery of low-cost, high-quality, customized products and services to customers who are increasingly demanding is critical to organizational success.

These changes in business practices are being reflected in modern office designs.

In the Past In the Past At PresentAt Present


Large areas filled with rows of clerks and typists conducting routine, repetitive tasks.

Most routine tasks, such as text typing and data entry, are now integrated into more complex, project-based work.

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Modern Work Environment (Cont.)

Private OfficePrivate Office Open-Plan OfficeOpen-Plan Office


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Office Design

Office Design (Cont.)


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You must take into your account how office design parameters (e.g. workstation size, ceiling type) affect physical office conditions (e.g. lighting, acoustics, indoor air quality), and occupant satisfaction.

Office Design: Noise


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Absorption properties of the ceiling, the workstation size, and the partition height have the largest effect on acoustic conditions since they are compensating for walls that would normally block sound travel between neighbors; however, no one element can control noise, and the most significant improvements in office acoustics occur when most of the office elements are well designed.

Do!Do! DO NOT!DO NOT!


Provide acoustic satisfaction with comfortable background noise and good speech privacy.

Block sound with absorbent surfaces (especially the ceiling) and high, wide partitions.

Provide a sound masking system.

Expose occupants to unacceptable noise sources, especially speech sources.

Create small workstations with low partitions.

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Practical tips: Noise

Office Design: Ventilation


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In any office, indoor air quality (IAQ) and thermal conditions are determined by the building’s ventilation system and by the contents of the office.

Poor conditions can result if contaminants, air delivery, and temperature are not properly managed.

Poor IAQ and thermal comfort are among the most common problems in offices. Poor conditions can be uncomfortable and make it harder to concentrate and work efficiently. They can also lead to symptoms such as headaches, sleepiness, or eye, nose and throat pain.

DO!DO! DO NOT!DO NOT!


Provide an adequate supply of outdoor air.

Provide some individual control over temperature, air velocity, and/or air direction.

Clean and maintain the ventilation system and the office space.

Create a comfortable thermal environment.

Insulate windows and provide perimeter heating/cooling.

Exceed air supply capacity of ventilation system.

Choose furnishings and equipment that emit high levels of contaminants.

Place workers close to contaminant sources.

Block air diffusers.Use very high

partitions.

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Practical tips: Ventilation

Office Design: Lighting and Day-lighting


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Light reflected off surfaces and objects reveals the world to us.

Good interior lighting reveals what we need to see, making details visible but also facilitating communication, setting the mood, and addressing health and safety. It does so in balance with the architectural characteristics of the space and practical considerations such as costs, energy consumption, installation, and maintenance.



Provide adequate task illumination.

Provide access to daylight.

Provide uniformity on task surfaces.

Create visual interest and a pleasant atmosphere.

Use fluorescent lamps with good color rendering.

Provide some individual lighting controls.

Allow walls and ceilings to be dark and cave-like.

Permit glare problems.Create a colorless,

blandly uniform office.Use glossy surfaces.

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Practical tips: Lighting

Office Design: Layout


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Offices exist primarily to allow employees to do their work, and, thereby, support their organization’s goals. Though work performance is the key function, a workstation should also provide a supportive environment for mental and physical well-being. Employees may spend upwards of 30% of their working hours per year in their offices, which need to be comfortable and satisfactory.



Furnish cubicles based on worker job needs.

Provide visual and acoustic privacy with enclosure (higher number of partitions, and larger workstations).

Provide adjustable furnishings and environmental controls.

Provide lockable storage for personal items.

Locate work groups in the same area.

Provide access to a window and a view.

Match alternative office strategies to tasks and employee needs.

Crowd worker. Make shared resources difficult

to access or place routes through work groups.

Place workers in busy, noisy areas of the office.

Prevent personalization of the workstation.

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Practical tips: Layout

Office Characteristics


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Partition height: Heights between 1.5 m and 1.8 m are recommended

Workstation size: Workstation of 6.3 m2 or greater are recommended.

Orientation: The orientation of workstation openings and of workers.

Office Layout: Isolate noise sources.

Office Etiquette: Encourages open-plan office workers to speak more quietly.

WORKSTATION DESIGN GUIDELINES


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Workstation Design

Workstation Design Guidelines


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There are 14 guidelines that must be taken into considerations by ergonomists when considering the design of a workstation.

Guideline 1Guideline 1


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Avoid Static Loads and Fixed Work Postures

Static load increases systolic and diastolic blood pressure.

Metabolic wastes accumulate in the muscles.

Consider increasing recovery time.

Avoid Static Postures

Employees should be encouraged to wear proper shoes for work requires lots of standing.

Workstations should be equipped with mats.Have hips parallel to the floor.Provide bar rail to vary work posture.

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Falls

Slips and falls are a major cause of injury deaths and have annual direct cost/capita of $50–400.

Causes of falls: Slips: unexpected horizontal foot movement Trips: restriction of foot movement Stepping-on-air: unexpected vertical foot movement

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Solutions for Falls

Prevent the fall: Use well-designed ladders, scaffolds, and ramps

properly. Provide safe steps. Use the three-contact rule. Provide good friction and reduce lubricants.

Reduce the consequences of the fall: Interrupt the fall. Soften the impact.

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Head Weight

The head weighs about the same as a bowling ball.

Keep the line of sight below the horizontal.Maintain forward head tilt of 10º-15ºAvoid backward and sideward tilts.

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Hands/Arms

An arm weighs about 4.4 kg.Avoid using the hand to hold up a tool or

work piece.Avoid working with elevated hands.Support the arms on the work surface or

chair arms.

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Reduce Musculoskeletal DisordersDon’t bend your wrist.Don’t lift your elbow.Don’t reach behind your back.Follow guidelines for hand and arm

motions.



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Set the Work Height at 50 mm Below the Elbow

Work height is defined in terms of elbow height.

Optimum height is slightly below the elbow.Optimum height from the elbow is the same

for sitting and standing.Work height is not table height.

Solutions for Work Height

Change machine height.Adjust elbow height.Adjust work height on machine.

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Video Display Terminal Workstations

Key items: screen, keyboard, document, eyes, hands

Workstation furniture must be adjustable.Locate the primary visual element first:

ahead of the eye, perpendicular to the line of sight.

Train the operator in adjusting the equipment.

Provide a wrist rest.

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Furnish Every Employee with an Adjustable Chair

The cost of an adjustable chair is very low compared to labor cost.

Allow users to try chairs in their specific jobs.

Buy chairs that are easily adjustable.Train people in proper adjustment.

Chair Design

Seats Seat Height from Floor Seat Length Seat Width Slope of Seat Seat Shape

Backrests Position of Backrest Molded Chair Back Position & Curvature

ArmrestsLegs/pedestals

Clearance of feet and calves under chair

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Use Gravity; Don’t Oppose ItMake movements horizontal or downward;

avoid lifting.Consider using the weight of the body to

increase mechanical force.Use gravity to move material to the work.Use gravity as a fixture.Use gravity in feeding and disposal.



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Conserve Momentum Avoid unnecessary acceleration and

deceleration.Use circular motion for moving and polishing.Eliminate grasping motions by providing

edges, rolled edges, and holes.Avoid transporting weight in the hand.



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Use 2-Hand Motions Rather Than 1-Hand Motions

Cranking with 2 arms is 25% more efficient than with one.

Using 2 hands is more productive despite taking more time and effort.

Don’t use the hand as a fixture.



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Use Parallel Motions for Eye Control of 2-Hand Motions

Minimize the degree of spread rather than worry about symmetry.

Estimate the cost of eye control with predetermined time systems.

Parallel vs. Symmetrical motions

BC DD B C C C A D B B

A D A A

Parallel motions•Shoulder moves•Easy eye travel

Symmetrical motions•Shoulder steady•Difficult eye control

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Use Rowing Motions for 2-Hand MotionsAlternation causes movement of the shoulder

and twisting of the torso.Alternation causes higher heart rates.Rowing motions are more efficient and

provide greater power.

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Pivot Motions About the ElbowMotion time is minimized with motion about

the elbow.Cross-body movements are more accurate

than those about the elbow.Physiological cost is lower for movements

about the elbow.

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Use the Preferred HandThe dominant hand is:

10% faster for reach-type motions More accurate than the non-dominant More exposed to cumulative trauma 5% to 10% stronger

Work should arrive from the operator’s preferred side and leave from the non-preferred side.



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Keep Arm Motions in the Normal Work Area

Avoid long benches.Use swing arms.For high use, keep it close.Remember the arm pivots on the shoulder,

not the nose.The shoulder is very sensitive to small

changes in workplace layout.



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Let the Small Person Reach; Let the Large Person Fit

Design so most of the user population can use the design.

Jobs must be designed for both sexes: Small or Large - Weld

Multi-person use of equipment and stations is becoming more common.

The proportion to exclude depends on the seriousness of designing people out and the cost of including more people.

ERGONOMIC COMPUTER WORKSTATION


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Workstation Design

Ergonomic Computer workstationErgonomic Computer workstation


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10 steps for a good ergonomic arrangement of a Computer Workstation:1. How will the computer be used? 2. What kind of computer will be used? 3. What furniture will you use?4. What chair will be used?5. What kind of work will the computer be used for?6. What can you see?7. Posture, posture, posture!8. Keep it close!9. Good Workstation Ergonomic Arrangement10. Where will the computer be used?

Step # 1: How will the computer be used?


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Who will be using the computer? 1. One person: then the arrangement can be optimized for that

person's size and shape, and features such as an adjustable height chair may be unnecessary.

2. Several people: you will need to create an arrangement that most closely satisfies the needs of the extremes, that is the smallest and tallest, thinnest and broadest persons, as well as those in between these extremes.

How long will people be using the computer? 1. If it's a few minutes a day then ergonomic issues may not be a

high priority. 2. If it's more than 1 hour per day it is advisable that you create

an ergonomic arrangement. 3. If it's more than 4 hours then you should immediately

implement an ergonomic arrangement.

Step # 2: What kind of computer will be used?


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Desktops : are the most widely and it means that the computer screen is separate from the keyboard.

Laptop computers: are growing in popularity and are great for short periods of computer work. Guidelines for laptop use are more difficult because laptop design inherently is problematic - when the screen is at a comfortable height and distance the keyboard isn't and vice versa.

Step # 3: What furniture will you use?


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Make sure that the computer (monitor, CPU system unit, keyboard, mouse) are placed on a stable working surface with adequate room for proper arrangement. If this work surface is going to be used for writing on paper as well as computer use a flat surface that is between 28"-30" above the floor (suitable for most adults).

You should consider attaching a keyboard/mouse tray system to your work surface.

Choose a system that is height adjustable, that allows you to tilt the keyboard down away from you slightly for better wrist posture, and that allows you to use the mouse with your upper arms relaxed and as close to the body as possible and with your wrist in a comfortable and neutral position.

Step # 4: What chair will be used?


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Choose a comfortable chair for the user to sit in. 1. If only one person is using this the chair can even be at a

fixed height providing that it is comfortable to sit on and has a good backrest that provides lumbar support.

2. If more than one person will be using the computer, consider a chair with several ergonomic features.

Best seated posture:1. Studies show that the best seated posture is a reclined

posture of 100-110 degrees

2. NOT the upright 90 degree posture that is often portrayed.

How to choose an ergonomic chair?


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An ergonomic chair should meet at least the following criteria:

1. Does the seat pan feel comfortable and fit your shape?2. Is the seat chair height adjustable?3. Is the range of height adjustment of the chair sufficient

to meet the needs of all users? 4. Does the chair have a comfortable lumbar (lower back)

back rest? 5. Is the chair back rest large enough to provide good back

support?6. When you sit back against the lumbar support is there

ample space for hip room?

How to choose an ergonomic chair? (Cont.)


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7. Does the seat pan still feel comfortable after you've been sitting in it for 60 - 120 minutes?

8. Does the chair backrest recline and support your back in different positions?

9. Does the chair have a 5 pedestal base? 10. Do you need armrests on your chair? 11. Do you need a footrest?12. What chair covering is best?13. Do you need an adjustable tilt seat pan ?

Step # 5: What kind of work will the computer be used for?


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Try to anticipate what type of software will be used most often.

1. Word processing: arranging the best keyboard/mouse position is high priority.

2. Surfing the net, graphic design: arranging the best mouse position is high priority.

3. Data entry: arranging the best numeric keypad/keyboard is a high priority.

4. Games: arranging the best keyboard/mouse/game pad is a high priority.

Step # 6: What can you see?


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Make sure that any paper documents that you are reading are placed as close to the computer monitor as possible and that these are at a similar angle - use a document holder where possible.

Take the following considerations into account to position the monitor:

1. Place it directly in front of you and facing you.2. Center the monitor on the user.3. Put the monitor at a comfortable height.4. Bifocals and progressive lens.5. Viewing distance.6. Screen quality.7. Eye checkup.8. Use a document holder that can be comfortably seen.

Step # 7: Posture, posture, posture!


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Good posture is the basis of good workstation ergonomics. Good posture is the best way to avoid a computer-related injury. To ensure good user posture:

1. Make sure that the user can reach the keyboard keys with their wrists as flat as possible (not bent up or down) and straight (not bent left or right).

2. Make sure that the user's elbow angle (the angle between the inner surface of the upper arm and the forearm) is at or greater than 90 degrees to avoid nerve compression at the elbow.

3. Make sure that the upper arm and elbow are as close to the body and as relaxed as possible for mouse use - avoid overreaching.

4. Make sure the user sits back in the chair and has good back support.

5. Make sure the head and neck are as straight as possible . 6. Make sure the posture feels relaxed for the user.

Step # 8: Keep it close!


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Make sure that those things the user uses most frequently are placed closest to the user so that they can be conveniently and comfortably reached.

Make sure that the user is centered on the alphanumeric keyboard. Most modern keyboards are asymmetrical in design (the alphanumeric keyboard is to the left and a numeric keypad to the right). If the outer edges of the keyboard are used as landmarks for centering the keyboard and monitor, the users hands will be deviated because the alphanumeric keys will be to the left of the user's midline. Move the keyboard so that the center of the alphanumeric keys (the B key, is centered on the mid-line of the user).

Make sure that the phone is also close to you if you frequently use it.

Step # 9: Good Workstation Ergonomic Arrangement


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A good workstation ergonomic arrangement will allow any computer user to work in a neutral, relaxed, ideal typing posture that will minimize the risk of developing any injury.

An ideal keyboard arrangement is to place this on a height adjustable negative-tilt tray.

An ideal mouse arrangement is for this to be on a flat surface that's 1-2" above the keyboard and moveable over the numeric keypad.

If you want a surface at the level of the keyboard base then make sure that this can also be angled downwards slightly to help to keep your hands in wrist neutral while you are mousing, and keep your elbow is as close to the body as possible while you work.

Step # 10: Where will the computer be used?


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Think about the following environmental conditions where the computer will be used:

1. Lighting: make sure that the lighting isn't too bright. You shouldn't see any bright light glare on the computer screen. If you do, move the screen, lower the light level, use a good quality, glass anti-glare screen. Also make sure that the computer monitor screen isn't backed to a bright window or facing a bright window so that there's the screen looks washed out (use a shade or drapes to control window brightness).

2. Ventilation: make sure that you use your computer somewhere that has adequate fresh-air ventilation and that has adequate heating or cooling so that you feel comfortable when you're working.

3. Noise: noise can cause stress and that tenses your muscles which can increase injury risks. Try to choose a quiet place for your workstation, and use low volume music, preferably light classical, to mask the hum of any fans or other sound sources.

Lighting

GENERAL TIPS


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Workstation Design

12 tips for an Ergonomic Computer Workstation


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Take a Break!

All Ergonomists agree that it's a good idea to take frequent, brief rest breaks: Practice the following:

1. Eye breaks: Every 15 minutes you should briefly look away from the screen for a minute or two to a more distant scene, preferably something more that 20 feet away. This lets the muscles inside the eye relax. Also, blink your eyes rapidly for a few seconds. This refreshes the tear film and clears dust from the eye surface.

2. Micro-breaks: most typing is done in bursts rather than continuously. Between these bursts of activity you should rest your hands in a relaxed, flat, straight posture.

3. Rest breaks: every 30 to 60 minutes you should take a brief rest break. During this break stand up, move around and do something else. Go and get a drink of water, tea, coffee or whatever.

4. Exercise breaks - there are many stretching and gentle exercises that you can do to help relieve muscle fatigue. You should do these every 1-2 hours.

5. Ergonomic software: working at a computer can be hypnotic, and often you don't realize how long you've been working and how much you've been typing and mousing. You can get excellent ergonomic software that you can install on your computer.


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Problem postures


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Desk top keyboard

Problem postures (Cont.)


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Conventional keyboard tray

Ideal Typing Position


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Negative slope keyboard support

Good Posture

Do NOT!Do NOT! DO!DO!


Looking forward to look at the screen, use the keyboard, and move the mouse.

Keep your back naturally curved. Support your lower back with a lumbar support.

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DO! & DO NOT!

Do NOT!Do NOT! DO!DO!


Keep your feet flat on the floor or the footrest. Do not tuck your feet under your chair.

Take breaks from sitting in you chair. Stand up, stretch

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DO! & DO NOT! (Cont.)

DO NOT!DO NOT! DO!DO!


Do not use a wrist rest. Position the keyboard so that your forearms are parallel to your thighs when your feet are flat on the floor.

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DO NOT!DO NOT! DO!DO!


Do not use a mouse that forces you to bend your wrist.

Keep your elbow close to your body and allow your arm to relax while you use the mouse.

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Good Vs. Poor Designs


76 Conventional

Arrangement Improved Ergonomic

Arrangement

Good Vs. Poor Designs (Cont.)


77 Conventional

Arrangement Improved Ergonomic

Arrangement

Mouse Use


78 Conventional Mouse

Arrangement

Improved Ergonomic Arrangement

Screen Adjustment


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The optimum position for the most important visual display, 15-50 degrees below the horizontal line of sight, according to the International Standards Organisation

April 10, 2023Lab # 3: Workstation Design 80

Documents

LAB # 3 Workstation Design. Outline June 11, 2014 Lab # 3: Workstation Design 2 Introduction. Ergonomic Design. Modern Work Environment. Workstation Design