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Ergonomy in work place. Ergonomy presentation Farnoosh Khodakarami Hengameh Vahabzadeh Supervisor:Mr.Ghayoor Fall 2006. Ergonomy in work place. Ergonomy:
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Ergonomy in work place Ergonomy presentation Farnoosh Khodakarami Hengameh Vahabzadeh Supervisor:Mr.Ghayoor Fall 2006
Ergonomy in work place Ergonomy: Derived from the Greek ergon (work) and nomos (laws) to denote the science of work, ergonomics is a systems-oriented discipline which now extends across all aspects of human activity. Ergonomists contribute to the design and evaluation of tasks, jobs, products, environments and systems in order to make them compatible with the needs, abilities and limitations of people
Domains of specialization within the discipline of ergonomics: - Physical ergonomics :is concerned with human anatomical, anthropometric, physiological and biomechanical characteristics as they relate to physical activity. relevant topics :working postures, materials handling, repetitive movements, work related musculoskeletal disorders, workplace layout, safety and health. - Cognitive ergonomics :is concerned with mental processes, such as perception, memory, reasoning, and motor response, as they affect interactions among humans and other elements of a system. relevant topics :mental workload, decision-making, skilled performance, human-computer interaction, human reliability, work stress and training as these may relate to human-system design.
Organizational ergonomics :is concerned with the optimization of sociotechnical systems, including their organizational structures, policies, and processes. relevant topics :communication, crew resource management, work design, design of working times, teamwork, participatory design, community ergonomics, cooperative work, new work paradigms, virtual organizations, telework, and quality management.
Work place layout work space :Physical design of a workspace includes working out how much space needed, and positioning of furniture, tools, equipment and any other items needed to perform the tasks, in respect of posture, access, clearance, reach and vision of the user. work space factors : • What type of task will be carried out and what specific actions are to be used to complete the task? • Will the potential users of the workspace (your user population) be seated or standing? • What postures will the users have to adopt? • What are the relevant body dimensions of the users? These dimensions can be found in anthropometric tables. • Do you need to design using minimum, average or maximum dimensions? • How far can the users reach, horizontally and vertically? • What are the visual aspects of the task?
Body dimensions - Designing for the 'average‘ - Designing for adjustability - Designing for extreme individuals The workspace envelope : A 'workspace envelope' is a 3-dimensional space within which you carry out physical work activities when you are at a fixed location.
Visual workspace : Frequently viewed items should be positioned within a comfortable zone in front of worker. This is normally within 15° above, or 30° below, the horizontal, and 15° to the left and right. In the normal, relaxed position of the head, neck and eyes, the line of sight is about 10 to 15° below the horizontal Distance is also a factor in visual fatigue. Visual displays are comfortably viewed from 500-750mm or more
Ergonomy in office work Features of an office such as people, space, equipment, furniture and the environment, must fit together well for workers to feel healthy and comfortable and to be able to work efficiently and productively. The Environment : The environment, or surroundings, in which workers are working includes temperature, ventilation, humidity, lighting, noise etc factors. • Lighting : - Most people like to be able to see daylight - Natural light is thought to make people feel better - Monitors need to be positioned so that there is no glare or reflection on the screen. - Most people like to be able to control the artificial lighting levels in their work area.
Light Source : The primary light source that man has relied on for thousands of years is the sun. The variation in light levels over the 24 hours of the dayis important for two reasons: - our bodies have natural rhythms - we appear to have a biological need for light Artificial light : two main types of lamps used to provide interior lighting : - incandescent light (light bulbs) - fluorescent tube Light Levels : different tasks need different minimum amounts of light to be performed at a satisfactory level ( Ex. paperwork and screen work as screens emit their own light ) Direction of light Glare
Temperature and ventilation : A suitable physical climate is needed to feel comfortable and be efficient at work. The environment feels comfortable when you are barely aware of the climatic conditions. It is only when the temperature decreases or increases beyond your comfort limits that you become aware of discomfort. comfort zone: 20-22ºC in winter 20-24ºC in summer
Noise : Noise is any annoying, disturbing or unwanted sound. Noise effects on people : • irritate people; • interfere with verbal communication; • reduce working efficiency; • disturb sleep; • damage hearing. The effects of noise: Deafness The main effect of noise is the development of deafness, especially when you are exposed to high levels of continuous noise. This may result in 'noise-induced occupational deafness'.
Noise and performance: Noise causes fatigue and loss of concentration and efficiency, resulting in a decrease in work output and an increase in the number of mistakes made The World Health Organisation (WHO) provides some guidance on acceptable levels of noise in the community.
Why ergonomics is important in office? Injuries like: WRULD: work related upper limb disorders Recent studies suggest a condition called e-thrombosis, an ailment where blood clots form as a result of sitting for a long length of time, is growing among professionals with desk jobs Repetitive Strain Injuries (RSI). Professionals who spend an extensive amount of time in front of computers are at high risk for Repetitive Strain Injuries (RSI). These musculoskeletal disorders, including carpal tunnel syndrome, tendonitis, lower back pain and tension headaches,
Posture at work • Changing your posture throughout the day is positive because when you change postures, the loads of sitting shift to different parts of the body, allowing your body to recover from extended static postures. • For most people, it is quite a challenge to maintain good posture while sitting in an office chair and working for long hours in front of a computer • a surprising number of people sit at the front of their office chair and hunch forward in an attempt to get closer to their computer screen • leaning forward 30 degrees in an attempt to get closer to the computer screen puts 3 to 4 times more strain on the back
Technique to avoid hunching while sitting in an office chair To avoid the natural tendency to hunch forward while sitting in an office chair and working at a computer, Place a tennis ball between the middle back and the office chair on each side of the spine • if one does get absorbed into work and starts to lean forward the tennis ball will fall out, serving as a concrete reminder to stop hunching forward and straining the back. • Because the mind senses the ball, it remains connected with the body instead of being completely absorbed by what is on the computer screen. Maintaining more awareness of the body allows one to more easily maintain better posture
posture • Your arms and legs Make sure that your upper arms are vertical (or close to it), and your forearms are horizontal (or close to it) so that there is approximately a right angle at your elbows • your shoulders should be relaxed, • your elbows should just about be level with the desk surface or very slightly above. If not, you should adjust your chair to get you to the height that allows this. • Your head and neck Aim to keep your neck vertical and relaxed and your head upright. • Look straight ahead at the screen, or slightly down (never up - too much muscle use!). Adjust the height of the screen if necessary. • Adjust the distance of the screen so that you can read the characters • Keep your wrists straight, in line with your forearms, and relaxed. • The forearm and hand make up 5% of an average body weight so improper positioning can result in fatigue
seat Saet Height The seat should be able to adjust until your thighs are parallel to theground. At a fixed-height work surface, the chair should be set at a height so the worker's elbows are level with the height of the workstation Saet pan The seat pan depth should be adjustable to provide a fist-width to three-finger gap between the back of the calf and the front edge of the seat pan. The seat pan should have a waterfall (rounded) front edge Sharp corners, even when they’re made of padding, increase the pressure on the backs of the thighs. A rounded front edge distributes the pressure over a larger area.
BackrestThe backrest height should be adjustable so the lumbar support can be fitted to the low backThe backrest should mirror the shape of your back to provide support. It should be able to support the natural curve of the spine • Armrests • Armrests should be adjustable. They should allow the user's arms to rest comfortably and shoulders to be relaxed. • They should be rounded on the edges. • Optional: most armrests are spaced too widely apart for the user to use them comfortably
Swivel • Any conventional style or ergonomic office chair should easily rotate so the user can reach different areas of his or her desk without straining
Seat material. The material on the seat and back of the ergonomic office chair should have enough padding to be comfortable to sit on for extended periods of time. Having a cloth fabric that breathes is preferable to a harder surface. • The chair should have at least 5 castors at the base to ensure stability FootrestsIf the feet cannot be firmly planted on the floor, then a footrest is required Footrests are way to shift postures or provide support for the feet if the chair cannot be loweredA footrest should be height adjustable. Adjust the footrest until the thighs are parallel to the floor +/- 1-3 inches
Desks • Desks are usually a standard height of about 720mm. This is fine for most people but. Particularly short or tall people may need an adjustable-height desk • . • You need enough desk space for your paperwork, the computer (monitor, keyboard and mouse) and any additional equipment that you need to do your job. • The desk should not have any obstructions underneath like drawers or supports, that force you to sit in uncomfortable positions • Some desks are 'radial' - L-shaped with a curve in the middle where you sit. These can be quite comfortable for computer work as you can have everything you need close at hand in an arc around you.
Keyboard • The keyboard should be positioned directly in front of the monitor • when the user's fingers are placed on • the keyboard, the forearms should rest parallel to the floor with the upper arms hanging comfortably to the sides. • The keyboard should not force the user's wrists into flexion. Constant flexion of the wrists will cause unnecessary muscle tension, which will often result in fatigue and injury • Place your keyboard in front of you with enough room to rest your hands when you are not typing.
MouseThe mouse should be positioned at the same height as the keyboard.The user should be able to access the mouse with their arm at a comfortable 90 angle to eliminate any strain on the shoulder.. Bring the mouse as close to the keyboard as you can so that you don't have to stretch to use it. Monitors • The top of the screen should be at or below eye level • 15” monitors are the minimum recommended size, though 17” monitors becoming increasingly common • The monitor should sit directly in front of the user • Adjust the distance of the screen so that you can read the characters clearly • The viewing distance to the computer screen should be between 13” – 28” to minimize eyestrain. Lighting is also very important. The monitor should be at a 90 angle to a window, where the light is least likely to produce a glare • Visibility: Keep the computer screen clean by wiping it very lightly when needed with a damp paper towel or monitor cleaning solution.
Phones (Headsets) Users who frequently use the phone and computer simultaneously or are on the phone for extended periods of time should consider a headset. Headsets reduce the tendency to cradle the phone and allow the user to work with both hands while conversing on the phone
Breaks – • Proper break periods are commonly overlooked when close to a deadline or in a period of intense work. Taking the recommended ergonomics breaks will increase energy, productivity and comfort while decreasing stress • Short Breaks every hour are recommended for workers to perform at peak ability and prevent injuries • Short, frequent breaks are more beneficial than longer, more infrequent ones. • Sitting for more than an hour without moving can put stress on the body due to the static posture that you are forced to sustain • Active breaks are a short time-out from typing or tasks being performing for an extended period of time. This is not a break from work, just a break from the activityThe user can get up and stretch, stand up while on the phone • Eye Breaks are one of the most important breaks for workers who spend most of their day staring at a computer screen. Eyestrain is a major cause of tension headaches • At least once an hour focus on an object that is at least 20 feet away. These few moments each hour can spare workers days of discomfort .
Exercises • a good exercise would be to stretch muscles that are opposing the ones that you normally use. This will allow you to achieve a balance within muscle groups. • Roll your head in circles, stretching more toward each shoulder • Eyestrain tip: Blink often, and take frequent rest pauses; close your eyes for a minute, refocus by looking away from your monitor at something in the distance, and roll your eyes up and down, left to right.