Ergonomics by lily wang

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HUMAN FACTORS

posture, motion, and ergonomics neck , back pain body- function degrees musculosketea disorders

our human body function

PA I N

HUMAN FACTORS

posture, motion, and ergonomics neck , back piain body- function degress musculosketea disorders

our human body function

PA I N

Copyright Copyright 2010 2010Consolidated ConsolidatedInc. Inc. All rights rights reserved. reserved.No Nopart partofofthis thispublication publicationmay may bebe reproduced, reproduced, stoed stoed in in retriveal retriveal system, system, or or tansmitted tansmitted in any in any form form by means by means electronic, electronic, mechanical, mechanical, photocopying, photocopying, recording recording or otherwise or otherwise without permission without permission of copy right ofholder copy right holder

This book dedicated to all of my friends Who help me how to find the strength and wisdom. To keep on reaching . Especially to my parents they bright my life and always support me.

TABLE OF CONTENTS

01_

HUMAN FACTOR STUDY

02_ INJURIES PREVENTIONS

what’s ergonomics?

Musculosketea Disorder Neck and Back Pain Neck and Back Pain

03_

FURNITURE DESIGN

Chair Design Desk Design Work Space Design

HUMAN FACTOR STUDY - ERGONOMIC

YOUR STUDY AREA IS CRUCIAL The International Ergonomics Association has adopted this technical definition: ergonomics (or human factors) is the scientific discipline concerned with the understanding of interactions among humans and other elements of a system, and the profession that applies theory, principles, data and methods to design in order to optimize human well-being and overall system performance. That is not the most efficient definition of what ergonomics is. Let us keep things simple. Ergonomics is the science of making things comfy. It also makes things efficient. And when you think about it, comfy just another way of making things efficient. However for simplicity, ergonomics makes things comfortable and efficient. At its simplest definition ergonomics literally means

Ma imporrum fugit

the science of work. So ergonomists, i.e. the practitioners of ergonomics, study work, how work is done and how to work better. It is the attempt to make work better that ergonomics becomes so useful. And that is also where making things comfortable and efficient comes into play. Ergonomics is commonly thought of in terms of products. But it can be equally useful in the design of services or processes. It is used in design in many complex ways. However, what you, or the user, is most concerned with is, â&#x20AC;&#x153;How can I use the product or service, will it meet my needs, and will I like using it?â&#x20AC;? Ergonomics helps define how it is used, how it meets you needs, and most importantly if you like it. It makes things comfy and efficient.

COMFORT

Reducing the strength

Reducing body stress

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ERGONOMICS

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secondary workplace

primary workplace

within arm’s reach.

the distance from elbow to hand.

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WHAT IS COMFORT ? Comfort is much more than a soft handle. Comfort is one of the greatest aspects of a design’s effectiveness. COMFORT IN THE HUMAN-MACHINE INTERFACE IS USUALLY NOTICED FIRST.

The prevalence is for keyboard users to use ‘clawed’ hands when us ing a keyboard to enter text. By this I mean when a user readies their hand position over the keyboard before they type, or whilst in thought between text entries, the hands can be seen to be extended into the air from the wrist in a ‘claw’ like shape (as pictured below). Often the wrists are leaning on a wrist rest, or worse still, leaning on just the hard desk surface Even worse, some users can actually continue typing with their hands in this claw like manner, with the fingers being held high over the keys like an eagle’s talons over it’s prey.

HANDS MOVEMENT

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Do not use the ‘claw shape’

The forearm extensor muscles

Do not use the ‘claw shape’ Do not use the ‘claw shape’

The forearm extensor muscles

The risks involved in this practice can be significant when done over a continuous period of time. The forearm extensor muscles are in continuous tension, as well as the tendons over the back of the hands and fingers. If held tense like this for long periods, the forearm muscles can fatigue very easily, ie they are being used in a way that they were not designed to be used for over protracted periods. Continuous use of this arm/hand pose over a keyboard or other input device can, if left unchecked, eventually progress to RSI like symptoms down the arms and into the hands and fingers. This may be explained by the forearm muscles being tighter than they should be, which in turn creates tension in the tendons that control the hands and fingers, leading to pain in these tendons as well as the muscles that control them. In worst cases (like my own) the forearm muscles seem to have a very small usage threshold before chronic fatigue sets in and pain occurs. This is attributable on my part to many years of bad keyboard practice, and using the ‘claw’. At this stage, I’m unsure whether these muscles or tendons will ever fully recover. Do not use the ‘claw shape’ wrist when typing on any keyboard. Try leaving your wrists in neutral position with no wrist or forearm tension. Try using the weight of your hands and fingers to hit the keys (not raising your individual fingers to do so.) This can be achieved by lifting your forearms/hands from the upper arms and shoulders as opposed to clawing the individual fingers back, which fatigues muscles and creates tension in tendons, ultimately leading to RSI like symptoms. Examine you forearm muscles for signs of pain. Press your thumb into the forearm muscle tissue about 3 finger widths down from the elbow bone, and see if these muscles are sore when pressed. If they are, then you may be putting yourself at risk of RSI, and should change your ergonomic practices to reduce the forearm muscle tension. Some relief for sufferers can be gained by massage of the upper forearm muscles. This can be done by the sufferer by either using a thumb to rub deeply into the forearm muscles tissue, or by use of an electric hand held massager. Alternatively a sufferer can obtain professional massage from a physiotherapist. The pained forearm muscles in can respond well to massage, but relief may be temporary since the pain is merely the symptom and not the root cause, which is bad posture.

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body- function degrees

body- function degress

our human body function body- function degress

Examine you forearm muscles for signs of pain

Some relief for sufferers can be gained by massage of the upper forearm muscles.

Press your thumb into the forearm muscle tissue about 3 finger widths down from the elbow bone,

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Keep your wrists straight and hands relaxed when using your pointer. Don’t hold the pointer with a tight grip or extend fingers above the activation buttons. Avoid moving the pointer with your thumb or wrist. Movement should originate at your shoulder and elbow. Limit repetitive motions. Reduce keystrokes with macros and software programs such as voice recognition. Reduce pointing device movement with scroll locks and keystroke combinations. Customize your computer settings. The screen font, contrast, pointer size, speed, and color can be adjusted to maximize comfort and efficiency. Reduce glare. Place your monitor away from bright lights and windows. Use an optical glass glare filter when necessary. Take eye breaks and intermittently refocus on distant objects. Try palming your eyes in your hands to reduce eye fatigue. Work at a reasonable pace and take frequent stretch breaks. Take 1 or 2 minute breaks every 20-30 minutes, and 5 minute breaks every hour. Every few hours, try to get up and move around. Use of non-prescribed medications, or wrist splints, can often be more harmful than helpful. If you begin to develop symptoms, seek help. Early intervention can prevent future problems. Your life style and physical fitness affect how you feel at work. Stay in shape by stretching and exercising regularly. Stretches and exercises can be found on our website. Repetitive and prolonged use of a computer keyboard and/or mouse can lead to muscle aches and discomfort. Posture and positioning are important. Try to incorporate the following tips into your work style to avoid problems. Maintain good posture when working. Sit all the way back in the chair against the backrest. Keep your knees equal to, or lower, than your hips with your feet supported. Keep your elbows in a slightly open angle (100° to 110°) with your wrists in a straight position. The keyboard tilt can help you attain the correct arm position. A negative tilt (front of keyboard higher than back) helps when working in upright sitting positions. If you recline, a positive tilt (front of the keyboard lower than the back) might be necessary. Avoid overreaching. Keep the mouse and keyboard within close reach. Center the most frequently used section of the keyboard directly in front of you. Center the monitor in front of you at arm’s length distance and position the top of the monitor 2” to 3” above seated eye level. You should be able to view the screen without turning or tilting your head up or down. Place source documents on a document folder positioned between your monitor and keyboard. If there is not enough space, place documents on an elevated surface close to your screen. Use good typing technique. Float your arms above the keyboard and keep your wrist straight .

Reducing the strength

Reducing the number of steps Reducing body stress MODEL NO: 94900002969422

Many tasks performed in research laboratories place workers at risk of muscle and joint aches and strains. Activities such as using pipettes, microscopes, microtomes, and centrifuges can put stress on your body. Use the following tips to lower your exposure to risk. Be Aware of Your Posture. Sit against the back of your chair. If you sit back and your feet dangle, lower the chair or adjust the foot ring or get a footrest. Try tilting the seat forward or use a seat wedge to work in a forward posture without leaning or jutting your head forward. Always try to work at a bench cut out. Cut outs can help you get close to your work while sitting against the back of your chair. Donâ&#x20AC;&#x2122;t jut your chin forward when working. Adjust the position of your work, the work surface, or the chair to sit in an upright, supported position. Keep frequently used trays and supplies within close reach. If standing for long periods, use supportive shoes and cushioned mats. Weight shift often when standing to work. Use a stool or shelf to prop up a foot to relieve pressure on your back. Keep Arms and Hands Relaxed Keep your shoulders relaxed and your elbows close to your sides when working. Avoid reaching out to use instruments and work materials. Maintain neutral or aligned wrist and arm postures when working. Sit close to your work area, keep objects close, and adjust your chair to match the height of the bench. Avoid reaching out to use instruments and work materials. Maintain neutral or aligned wrist and arm postures when working. Sit close to your work area, keep objects close, and adjust your chair to match the height of the bench. Avoid repetitive or forceful twisting and turning motions (i.e. opening valves or adjusting microscopes). Make sure valves and knobs are clean and in good working order. Work with your wrist in a neutral or straight position as if you were shaking hands with someone. Use light pressure when performing tasks such as pipetting.Use electronic pipettes or light touch models whenever possible. Select equipment and tools that are the right size for your hand. Use padding and tubing to reduce pressure and force when working. For example, use rubber tubing on forceps. To increase diameter and reduce pinch force. Soften sharp edges on work surfaces with padding. Use thin, flexible gloves that fit properly. Ill fitting and poorly designed gloves increase pinch and grip forces when working. If standing in one spot for long periods, use cushioned floor mats or shoes with good support. Alternate how you hold objects like forceps. Switch holding with the thumb and index finger, and the index and middle fingers to vary the task. Vary activities. Change your position and take breaks every 20 minutes to rest muscles to rest and increase blood flow and circulation.

AVOID STATIC POSITIONS BE AWARE OF YOUR POSTURE KEEP ARMS AND HANDS

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ESIGN METHOLOGY CLINICES AM NO: 2402 AME. LBIEUGIOW

STUDY YOUR BODY ANGLE

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The connection between feet and posture does not receive major emphasis in medical education. Generally, the impact of the foot foundation continues to be overlooked. Here is a very brief review: You are probably familiar with the term pronation, but maybe you were not aware that just like there are two kinds of cholesterol, there are two kinds of pronation. Normal (good) pronation is purposefully directed from the hips to unlock the foot in preparation for the heel striking the ground during gait. It enables the foot to cushion the impact. Hyperpronation (bad) has its origin in the skeletal structure of the feet. It causes the longitudinal arch to collapse and ankle to roll inward, when the foot becomes weight bearing.

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THE CONNECTION BETWEEN YOUR FEET AND POSTURE Hyperpronation causes an internal rotation of the lower extremities. Because the left foot typically hyperpronates more than the right, the asymmetrical internal leg rotation typically causes the left innominate to be pulled forward and down more than the right causing an unleveled pelvis and a functional leg length discrepancy. As these displacements cascade up the axial framework, scoliotic and kyphotic curves are exaggerated. The thoracic cage usually twists counterclockwise, the left shoulder usually protracts more than the right, and the right shoulder drops. The maxilla moves anteriorly causing an overjet bit. Imply stated, the feet can be compared to the foundation under a building. If the foundation sags, so does the building. A forward leaning, head forward posture is common among 80% of your patients. People are and look off balance. Maximal stresses are placed on the body just from standing and walking. Over time damage is done to joints, ligaments and muscles.

59 Using computers for extended periods can cause visual discomfort, headaches and vision challenges. It is very unlikely that you will suffer permanent changes or damage to your eyes. Rather, you may experience these symptoms whenever you use a computer intensively for periods of a couple of hours or longer; the symptoms will diminish soon after you stop working on the computer. Typical symptoms of vision challenges include: Eye strain refers to ocular fatigue, eye discomfort and headaches associated from intensive use of the eyes. Common causes include: Eye strain refers to ocular fatigue, eye discomfort and headaches associated from intensive use of the eyes. Common causes include: glare on the computer screen poor visual correction (out of date eyeglass prescription) reading small character sizes on the screen poor contrast between text and background on the monitor noticeable screen flicker dry eyes. If you feel your eyes become dry or tired with computer activities, remember to take frequent vision breaks. Breaks can include momentarily closing your eyes or looking away from the screen. If your eyes tend to feel dry or you wear contact lenses, eye drops of an artificial tear substitute may also help prevent or relieve symptoms . Task lighting is typically provided from desk lamps. Be sure to adjust the position of your task lighting to maximize illumination for visually demanding tasks while minimizing glare on the computer screen. Glare on the computer screen is a common problem. The first step to reducing glare is to control it at the source; close window blinds, turn off hallway lights, and reposition task lighting. The second step is to minimize the effects of glare on your screen; use a monitor glare screen or hood, change your monitor position and tilt, and adjust your brightness/contrast controls.

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SCINILC YGOLOHTEM NGI 2042 :ON M WOIGUEIBL .EM

50 DEGREE

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

body- function degrees

body-

function

de-

body- function degrees

our human body function

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MEASUREME

body- function degrees

body- function degress body- function degrees

our human body function

DESIGN METHOLOGY CLINICS EXAM NO: 2402 NAME. LBIEUGIOW

ENTS, ALSO KNOWN AS â&#x20AC;&#x2DC;ANTHROPOCENTRIC DATAâ&#x20AC;&#x2122;,

MUSCULOSKETEA DISORDERS Macroergonomics is an approach to ergonomics that emphasizes a broad system view of design, examining organizational environments, culture, history, and work goals. It deals with the physical design of tools and the environment. It is the study of the society/technology interface and their consequences for relationships, processes, and institutions. It also deals with the optimization of the designs of organizational and work systems through the consideration of personnel, technological, and environmental variables and their interactions. The goal of macroergonomics is a completely efficient work system at both the macro- and micro-ergonomic level which results in improved productivity, and employee satisfaction, health, safety, and commitment. It analyzes the whole system, finds how each element should be placed in the system, and considers all aspects for a fully efficient system. A misplaced element in the system can lead to total failure

21 MODEL NO: 94900002969422

Project Type 4 ergonomics exhibition

xhibit

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0002969422

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Macroergonomics is an approach to ergonomics that emphasizes a broad system view of design, examining organizational environments, culture, history, and work goals. It deals with the physical design of tools and the environment. It is the study of the society/technology interface and their consequences for relationships, processes, and institutions. It also deals with the optimization of the designs of organizational and work systems through the consideration of personnel, technological, and environmental variables and their interactions. The goal of macroergonomics is a completely efficient work system at both the macro- and micro-ergonomic level which results in improved productivity, and employee satisfaction, health, safety, and commitment. It analyzes the whole system, finds how each element should be placed in the system, and considers all aspects for a fully efficient system.

Macroergonomics

Fields of ergonomics muscular force

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8.8% decrease in hand

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Design of ergonomics experiments

> NECK AND BACK PAIN >

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PAIN

SIGN METHOLOGY CLINICS AM NO: 2402 ME. LBIEUGIOW

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AVOIDING NECK AND BACK PAIN AT WORK

Neck and back pain at work is a common cause of doctor visits. It is widespread across many occupations, from heavy construction work to light office work, and it reduces work productivity. Social-economic costs associated with neck and back pain at work, including reduced work productivity, lost wages, and treatment costs, are substantial. Many factors at work pose risk for joint, neck, and back pain and can cause musculoskeletal disorders such as carpal tunnel syndrome, muscle strains, disc herniation, tendonitis, and bursitis. Ergonomics is the scientific study of humans and their work. It uses anatomical, psychological, and mechanical principles to increase the efficiency of using human energy. Workplace ergonomics designs tasks and workplace environments to fit the workersâ&#x20AC;&#x2122; physical capabilities, not forcing the workers to fit the environments Heavy lifting. Frequent and heavy lifting can cause muscle strains, ligament sprains, disc bulge, and even bone fractures. Repetitive motion. Overly repetitive tasks such as computer data inputting can lead to muscle fatigue and injury if performing the tasks for extended periods of time. Whole-body vibration. Studies have shown that whole-body vibrato n caused by reasons such as driving a motor vehicle on a rough road coincides with the natural frequency of the spine, making the spine and back tissue vulnerable to injury from resonance. Static posture. Prolonged static postures such as sitting or standing for extended periods of time put too much pressure on the discs and joints of the back, which could lead to neck and back pain. Stress. Heavy workload and pressure increase stress in the workplace. High stress can cause muscle tightness and lead to neck and back pain.

Support your lower back with your chairâ&#x20AC;&#x2122;s back rest naturally aligned

Maintain a neutral sitting posture in which your joints are naturally aligned

GN METHOLOGY CLINICS NO: 2402

. LBIEUGIOW

ADJUSTABLE HEIGHT BACK ANGLE ADJUSTMENT LUMBAR SUPPORT

The most common condition that contributes to neck pain is forward head and shoulder posture. Forward head posture is when the neck slants forward placing the head in front of the shoulders. This head position leads to several problems: The forward pull of the weight of the head puts undue stress on the vertebrae of the lower neck, contributing to degenerative disc disease and other degenerative neck problems. Similarly, this posture causes the muscles of the upper back to continually overwork to counterbalance the pull of gravity on the forward head. This position is often accompanied by forward shoulders and a rounded upper back, which not only feeds into the neck problem but can also cause shoulder pain.

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71-79

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The more time spent with a forward head posture, the more likely it is that one will develop neck and shoulder problems. The part of the neck that is particularly vulnerable to forward head posture is the lower part of the neck, just above the shoulders. The lower cervical vertebrae (C5 and C6) may slightly slide or shear forward relative to one another as a result of the persistent pull of gravity on a forward head. This shear force can be a problem for patients with jobs that require them to look down or forward all day, such as pharmacists who spend many hours counting pills or data entry workers who look at a computer screen. Prolonged shearing of the vertebrae from forward head posture eventually irritates the small facet joints in the neck as well as the ligaments and soft tissues. This irritation can result in neck pain that radiates down to the shoulder blades and upper back, causing a variety or potential conditions.

ERGONOMICS FURNITURE DESIGN

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ADJUSTABLE HEIGHT BACK ANGLE ADJUSTMENT LUMBAR SUPPORT SEAT WIDTH

SEAT WIDTH SEAT WIDTH DESIGN METHOLOGY CLINICS EXAM NO: 2402 NAME. LBIEUGIOW

Support your lower back with your chair’s back rest naturally aligned Maintain a neutral sitting posture in which your joints are naturally aligned

Place your feet slightly out in front of your knees and rest them comfortably on the floor or a footrest

CHAIR DESIGN Finding the right ergonomic chair is a common problem especially for people who want to purchase new equipment to make workstations safer and healthier places. There are many “ergonomic” chairs available but it can be a mistake to purchase one simply because it is labelled “ergonomic”. Ergonomic chairs are designed to suit a range of people; however, there is no guarantee that they will suit any one person in particular. For example, a chair could be too high and the arm rests too far apart for a short, slim person. In addition, chairs may not suit every task or arrangement at the workstation. A chair becomes ergonomic only when it specifically suits a worker’s size (body dimensions), his or her particular workstation, and the tasks that must be performed there. It is possible to find the right chair although it is not always easy.

GUIDE TO SETTING UP AN ERGONOMIC WORKPLACE

Breakthroughs in technology that would change the nature of work, such as Macroergonomics

the desktop

Fields of ergonomics computer, muscular force

The need for

organizations to adapt to the expectations and

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needs of this more mature workforce,

WORK STATION

If you are working in an office like the majority people do, odds are when you take time out the topic of discussion will be backache. Most of the time, we are aware of causes of these complaints, which is either sitting tightly for extended hours or drooping while sitting at work desk. Sitting at a work desk for extensive hours can actually cause aching back owing to combination of two factors, bad sitting posture and a chair that does not correctly provide support to proper sitting posture. Now the question comes up, have we found out a remedy to circumvent or lessen this? Weirdly, the reply is positive. Nevertheless, we are not applying that understanding into real life. Suggestions of medical practitioners have been overlooked in most cases on how to lower neck and back pain thanks to recent office culture. They have been educating us to take time out and do regular work outs for four to five minutes every few hours or so nevertheless we just overlook. Hence using different modes like the ergonomic office chair makes sense, which provides good back support; supports correct sitting posture and provides comfort. A large number of offices have normal office chairs nevertheless, by spending slightly more, you can get chairs that can in fact help recuperate and possibly even put back backache. Adjustable office chairs are excellent since these are designed to give best support to the back and can be adjusted as per your bodyâ&#x20AC;&#x2122;s unique curve. First-rate ergonomic office chairs give outstanding support to lower back, lumbar and seat area and avoid stress from building up even after extended hours of being seated, making a body-friendly working ambiance. These chairs are designed to preserve your body in excellent shape. While designing these chairs producers keep crucial facets like using computer, listening phone calls, reaching file cabinets in mind and make them adjustable, which is particularly useful.

Donâ&#x20AC;&#x2122;t let light shine in your eyes or on your screen.

SEAT WIDTH

Use a well made adjustable office chair

Square screen to your line of vision

SPINE

SLIPPED OR HERNIATED DISK

HEADACHES

NECK & SHOULDER PAIN

AN ERGONOMIC CHAIRS If you work in an office then you probably spend up to 40 hours or more each and every week in a typical office chair. Sitting in the same position day after day, week after week and year after year can take a toll on your body, if it’s not an ergonomic chair. If you already are experiencing pain in your back, neck, legs, wrists or other areas of your body then you are only compounding the problem. In order to avoid making your pain worse and perhaps alleviate your pain you should make sure you are seated in an ergonomic chair. Ergonomic chairs will support your lower back and promote good body posture all over. There is no “one-size-fits-all” solution because every person is a different size and uses their workstation differently. That’s why we first identify your pain areas, your body size and how you use your workstation to custom make an ergonomic chair to fit your exact needs. We then let you try it risk free for 30 days to make sure it truly relieves your pain and boost your productivity. We have been in the business of building custom ergonomic chairs for over 15 years and no two people are just alike. Each individual not only has a difference size and shape but also uses their chair differently. A lot of time, effort and analysis goes in to each of the ergonomic chairs we build because we want the chair you get to fit YOU. Other so-called “Ergonomic Chairs” websites and mass office furniture retailers offer what they call “ergonomic chairs” but it is nothing more than a cheap attempt to sell an uninformed customer something that will not last much less offer the benefits of a true Ergonomic Chair.

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OFFICE FURNITURE GUIDELINES When designing offi ce furniture there are many things to consider and several sources to reference for ergonomic principles, anthropometrics, fi t, and function of a product.One common and widely recognized source for this kind of information is The Business and Institutional Furniture Manufacturer’s Association (BIFMA). There are several documents that are helpful in deciphering the reasoning and/or theory behind the BIFMA guidelines and specifi cations. During early design stages, the product can be tested on different subjects to verify anthropometric fit and improve the design with items not originally considered. BIFMA’s guidelines for seating are very general and allow for different design interpretations. The suggested BIFMA measurements are illustrated in Figure 8 and listed in Table 3 on page 24. These guidelines are based on the Natick military studies using 5th to 95th percentile females and males.

SEAT HIGHT

SEAT DEPTH

SEAT WIDTH

SEAT MEASURMENT

BACKREST LUMBAR

BACKREST WIDTH

ARMREST HEIGHT

CHAIR CONTROL The controls are important, but the fewer and more intuitive they are, the better it can be for the user. A round knob usually means that it should be turned. A ďŹ&#x201A; at lever usually means it should be pulled or pushed. Some controls are lso easier for individuals with disabilities to use than others (refer to the Universal Design graphic icons could be placed on the controls to show the user how to operate each lever or device. Images, rather than text, .

The forearm extensor muscles

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Breakthroughs in technology that would change the nature of work, such as the desktop computer, The need for organizations to adapt to the expectations and needs of this more mature workforce,

Adjustable height desk and ergonomic desk - Usually the best ergonomic desk for a computer user will be an electric adjustable height desk that encourages sit to stand posture changes throughout the day. A comfortable sit to stand desk can lead to better productivity because fatigue and discomfort is reduced. Electric height adjustable desks are recommended because they are the easiest to operate and we find that our customers use their desk more if it is electrically powered instead of crank or manually powered. .

safe postures

body- function degrees mid-point of their range of movement

appropriate muscle groups available MODEL NO: 94900002969422

600mm

8.8% decrease in hand

SOLUTIONS FOR A SAFER WORKPLACE

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As early as the 18th century, doctors noticed that workers whose jobs required them to maintain certain body positions for long periods of time developed musculoskeletal problems. In the last 20 years, research has clearly established the connection between certain job tasks and repetitive stress injuries, or RSI’s. Two elements are at work here: “static work” and “force.” “Static work” refers to the musculoskeletal effort required to hold a certain position, even a comfortable one. For example, when we sit and work at computers, keeping our head and torso upright requires either small or great amounts of static work depending upon the efficiency of the body positions we choose. “Force” refers to the amount of tension our muscles generate. For example, tilting your head forward or backward from a neutral, vertical position quadruples the amount of force acting on your lower neck vertebra. This increase of force is due to the increase in muscular tension necessary to support your head in a tilted position. The term “ergonomics” is derived from two Greek words: “erg,” meaning work and “nomoi,” meaning natural laws. Ergonomists study human capabilities in relationship to work demands. In recent years, ergonomists have attempted to define postures which minimize unnecessary static work and reduce the forces acting on the body. All of us could significantly reduce our risk of injury if we could adhere to the following ergonomic principles: Here, however, we arrive at a problem: In order to put these recommendations into practice, a person would have to be a skilled observer of his or her own joint and muscle functioning and would have to be able to change his or her posture to a healthier one at will. No one develops this sort of highly refined sensory awareness without special training. Therefore, in order to derive the benefits of ergonomic research, we must learn how to observe our bodies in a new way.

Millions of people work with computers every day. This eTool* illustrates simple, inexpensive principles that will help you create a safe and comfortable computer workstation. There is no single “correct” posture or arrangement of components that will fit everyone. However, there are basic design goals, some of which are shown in the accompanying figure, to consider when setting up a computer workstation or performing computer-related tasks. Consider your workstation as you read through each section and see if you can identify areas for improvement in posture, component placement, or work environment. This eTool provides suggestions to minimize or eliminate identified problems, and allows you to create your own “custom-fit” computer workstation.

CLASS: Typography 4

COVER DESIGNER: Li Wang

INSTRUCTOR: Ariel Grey

TYPE FACE: Minion , Swiss 721

BOOK DESIGNER: Li Wang

PRINTER: Epson Photo 1400 PAPER: PAPER WEIGHT: ENTRADA 190 GSM

The original source for this book was gather from internet deta research. The diagrams and illustration in the book were created using Adobe Illustrator, and the text for the book was designed by Adobe In Design. Photogra phs were enhance and processed using Photoshop.