Ergonomics Information
The factor of ergonomics is extremely important when purchasing office furniture. The economic reality of the workplace dictates that it is better to spend a little more on an ergonomically correct chair or work center then face the consequences of an injured employee.
The first section explains ergonomics with the second section being a checklist to design your office workspace to be ergonomically correct.
What is ergonomics? Ergonomics is the science of fitting the job to the worker. When there is a mismatch between the physical requirements of the job and the physical capacity of the worker, work related musculoskeletal disorders (WMSDs) can result. Workers who must repeat the same motion throughout their workday, who must do their work in an awkward position, who must use a great deal of force to perform their jobs, who must repeatedly lift heavy objects or who face a combination of these risk factors are most likely to develop WMSDs.
How serious a problem are WMSDs? In 1996, U.S. workers experienced more than 647,000 lost workday WMSDs. WMSDs now account for 34 percent of all lost workday injuries and illnesses. These injuries cost business $15 to $20 billion in workers' compensation costs each year. Indirect costs may run as high as $45 to $60 billion.
Workers who experience WMSDs may be unable to perform their jobs or even simple household tasks. WMSDs represent real workplace problems faced by real people. The scientific basis for the relation between work and development of WMSDs and for addressing ergonomic problems in the workplace is well established.
What can be done to prevent WMSDs? Real solutions have been demonstrated in workplaces of all sizes across a broad range of industries. Many employers have developed effective ergonomics programs and common sense solutions to address WMSDs in their workplaces. Often WMSDs can be prevented by simple and inexpensive changes in the workplace. Adjusting the height of working surfaces, varying tasks for workers and encouraging short rest breaks can reduce risks. Reducing the size of items workers must lift or providing lifting equipment also may aid workers. Specially designed equipment, such as curved knives for poultry processors, may help.
What is OSHA doing to address WMSDs? OSHA is developing a program that calls for employers to establish ergonomics programs to prevent WMSDs. The agency has pledged to focus on jobs where injuries are high and solutions well demonstrated. In consultation with stakeholders, OSHA has identified significant problems for workers involved in production operations in manufacturing and manual handling throughout general industry. Job related musculoskeletal disorders also occur in other jobs. At a minimum, employers that have workers experiencing injuries need to address the problem.
One size does not fit all. That is why OSHA has decided on the program approach. That's also why no one will ever be able to say that X number of repetitions or lifting X pounds will result in injury or conversely that Y number of repetitions or Y pounds will definitely NOT result in injury for anyone, any time, anywhere. However, many employers have proven that establishing a systematic program to address such issues as repetition, excessive force, awkward postures and heavy lifting, results in fewer injuries to workers.
What components should an ergonomic program include? OSHA has identified the following critical elements: management leadership and employee participation, hazard identification and information, job hazard analysis and control, employee training, medical management and program evaluation. The agency also intends to include in the rule a grandfather clause for existing programs.
The keys to success are simple: reduce repeated motions, forceful hand exertions, prolonged bending or working above shoulder height. Reduce vibration. Rely on equipment - not backs - for heavy or repetitive lifting. Provide "micro" breaks to allow muscles to recover.
When will OSHA publish the ergonomics program rule? OSHA published its proposal in the Federal Register in November 1999. The agency will take public comments and hold hearings in Washington, DC (February 2000), Portland, OR (March 2000), and Chicago, IL (April 2000). After the hearings, there is another comment period to allow people who testified at the hearings to provide more information. OSHA is targeting the end of calendar year 2000 to issue the final ergonomics standard.
Performance Oriented Ergonomic Checklist For Computer (VDT) Workstations (adapted from ErgoWeb,1996 by the Cornell University Human Factors Group, Dept. Design & Environmental Analysis, 1996) Introduction
Among ergonomists there is general agreement with regard to proper computer workstation set-up, and the optimal body postures assumed by people performing tasks at the workstations. Unfortunately, quick and easy solutions to ergonomic problems, such as wrist rests, seldom help and sometimes they actually make matters worse. Likewise, recommending specific dimensions for workstations without knowledge of the anthropometrics of each user, the dimensions of equipment, and the nature of the work to be done can result in sub optimal workstation arrangements.
This performance oriented checklist is designed to help you to evaluate what is needed for a good ergonomic workstation arrangement. Specific dimensional constraints intentionally are omitted and replaced by a principles oriented approach for this checklist. A checklist is a guide to good decision making, not an end point in itself. No checklist alone is able to capture the interactions and complexities of all possible combinations of people, task, equipment, and work environment. However, use of this checklist, along with an understanding of the principles of Ergonomics, will allow you to identify workstations which need redesign work, and it will give you guidance on the goals of any workstation redesign that is required.
At a minimum, while using this checklist, remember that designing for ergonomics requires understanding and consideration of
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, computer software, and other workstation accessories the tasks required to perform the job the work environment, including such things as noise and temperature, but also management and organizational methods and constraints
The interaction between these general topics is critical, and will define the postures, forces, and repetitions assumed by the person(s). Remember, all parts of the body are linked together, and consequently a modification in one area may have significant effects in another, no single change can be performed without considering the effects on other areas. For example, lowering seat height so that someone may comfortably rest his/her feet on the floor may force a stressful upper body posture if the monitor position and table or keyboard height are not adjusted in concert (this is often a good reason to provide a footrest).
When using this checklist,
ask not whether the person can merely achieve these general goals, but whether the design of the workstation, task, and environment interfere with, obstruct, or outright inhibit a person from achieving them. remember that it is worded for use when reviewing one person and that person's VDT workstation, tasks, and working environment. If more than one person must use the same workstation, the checklist should be applied to each individual, and an easily adjustable workstation becomes even more important. remember that there is no "perfect posture for all time" and that a dynamic posture (frequent changes in posture) is a good way to reduce stress and redistribute pressure related to long duration static postures. However, work can be sustained for longer times without causing harm if the person is working in a neutral posture. remember that the checklist is not all inclusive, and may not cover all of the topics important to your specific situation. remember that a good ergonomics approach will improve comfort, productivity and quality, as well as health and safety.
"NO" responses indicate conditions that may be associated with higher risk of illness/injury and steps should be taken to address the source of the problem.
VDT Posture Checklist
1. POSTURE
"NO"; answers to ANY posture question identify the item that may be contributing to ergonomic risk and this should be addressed immediately. For a more detailed and systematic analysis of postural risks this checklist should be followed up by undertaking a Rapid Upper Limb Assessment ( RULA) analysis of the worker's posture.
Lower Extremities
Is the person able to rest the feet comfortably? Is the person able to sit with the knees in a comfortable position? Is the person free of uncomfortable pressure points, obstructions, or other interferences in the lower extremities?
Upper Extremities
Is the person able to work with the head in a vertical orientation, such that the neck is not stressed by holding the head off balance from the neck and shoulders? Is the person able to work with the head facing forward of the plane of the upper body the majority of the time, such that repetitive or long duration head rotation is minimized? Is the person able to reach to objects on the workstation without extended reaching, especially where the reaching is held for long durations, is repetitive, or requires trunk/torso deviations?
Is the person able to work with comfortable arm positions, or approximately:
neutral shoulder positions (upper arms tucked close to the body and hanging relaxed, not abducted out to the side, extended forwards or backwards, raised up, or hunched)? comfortable elbow positions that do not force shoulder or elbow positions from approximately neutral? neutral wrist positions (hands in a straight line with the lower arms, hands not flexed down towards the palm not extended up, nor bent towards the little finger, nor bent towards the thumb)? Force Static Body Posture
Do the workstation design and job requirements cause non neutral body positions to be held constant for extended periods of time?
2. WORKSTATION AND ENVIRONMENT DESIGN FEATURES
Seat Surface
Is the seat surface height adjustable, such that the person is able to set it at an individually comfortable height in relation to the required work activities? Is the seat surface of appropriate size, such that it is deep and wide enough to comfortably accommodate the specific person? Is the seat slope adjustable, such that the person is able to achieve a comfortable angle, either forward or rearward sloping?/li> Is it comfortable and is the front well rounded ("waterfall" front edge), such that the person does not experience excess pressure on the under side of the leg due to the forward edge? Overall, is the seat comfortable to the person that is required to use it?
Seat Backrest
Can the person easily adjust its height to provide mid lumbar support (lower back region)? Can the person easily adjust its angle relative to the seat surface? Can the person easily adjust it to alter the depth of the seat? Overall, is it comfortable to the person that is required to use it?
Work Surface
With the lower limbs in comfortable positions and feet on the floor, can the person achieve a comfortable work surface height? Is the width of the work surface appropriate, such that all required task accessories and duties can be located within comfortable reach and viewing distance? Is the depth of the work surface appropriate, such that the computer, and keyboard if necessary, can be placed directly forward of the person with the work orientation parallel to the plane of the upper body? Is the area under the desk large enough to accommodate the legs and any accessories, such as footrests and arm rests.
Computer Monitor (VDT)
Is the person able to easily adjust the height of the monitor? Is the person able to easily adjust the fore-aft distance of the monitor? Is the person able to easily adjust the tilt (up/down) angle of the monitor? Is the person able to easily adjust the yaw angle (left/right rotation) of the monitor?
Keyboard
Is the keyboard detachable from the VDT/computer monitor? Is the person able to easily adjust keyboard height? Is keystroke pressure comfortable to the person? Has the person correctly adjusted the angle of the keyboard so that their hands/wrists are in a neutral posture when they are typing? Placing the keyboard in a preset angle negative tilt keyboard tray that is height adjustable allows users to access the keyboard in a wrist neutral posture.
Mouse
Is the shape and button activation comfortable and easy to operate for the person? Is the person able to reach and operate the mouse without extended, long duration, or repetitive reaching and with the shoulders, arms and wrists in a neutral posture? Is the mouse on a position adjustable platform surface, so that this can be used within the person's immediate reach zone?
Document Holder for Data Entry Tasks
Is there a special holder or support for the source document? Is the person able to easily adjust the document holder height, distance and angle? Does the device prevent the document from vibrating? Is the device located such that the person is not required to twist the head/neck back and forth between the document and screen extensively or for long durations?
Support for the Hands and Arms
Are seat or other padded armrests available? Are armrests adjustable (height, lateral position)? Is a broad, flat keyboard palm support available to support the hands in a neutral posture in between bursts of typing movements? (Not a wrist rest. Most wrist rests are soft and curved. They can put extra pressure on the carpal tunnel which lies at the wrist increase, and this increases the risk of an ergonomic injury). Is the palm supported for mouse use?
Support for the Feet
Are the feet flat on the floor when the person is sitting comfortably at the workstation? Is a footrest available if needed and can the person able to easily adjust its height and its tilt? Office Lighting
Are lighting levels in the VDT/computer monitor area comfortable to the person? Is the monitor screen placed such that light from windows and overhead lighting do not cause glare? If not, are glare screens or other glare reducing methods used? Are diffusers, cube louvers or parabolic louvers used on overhead lights where screen glare from that source is a problem, or is indirect lighting used? Are movable task or desk lights available? Do work surfaces have a matte finish to reduce light reflection? Do windows have curtains, drapes or blinds to block light where glare from that source is a problem?
Temperature
Is the person comfortable with the ambient temperatures? Is the person comfortable with the temperatures of any equipment or surfaces s/he must contact?
Vibration
Does the person experience any uncomfortable building vibration (e.g. from mechanical systems, outside traffic)? Does the person experience any uncomfortable equipment vibration (e.g. from internal fans)? Does the person experience any uncomfortable keyboard vibration (e.g. wobble from an unstable keyboard tray)?
Noise
Are sound levels at comfortable levels, allowing conversation and other communications without significant effort? Does the person experience any uncomfortable equipment noise sources (e.g. printer noise)?
Ventilation
Is air circulation sufficient? Is air quality satisfactory? Is the air too dry or too humid?
Electrostatic Electricity
Does the person frequently experience static electricity shocks?
3. THE WORKER
Fatigue Control
Is the person allowed to take rest pauses or breaks from tasks that require long duration or repetitive postures, forces, keying or mousing activities? Is there job rotation or substitution of tasks which require a different type of activity where posture, force, and repetition hazards have not been addressed by design?
Vision
Does the person wear bifocal glasses, causing him/her to tilt the head to see through the appropriate lens area? Are workers with symptoms of eye strain, burning sensation in the eyes, blurred vision, irritated eyes, or headache examined for vision problems?
Psycho-Social Issues
Does the person have some involvement and control over the work process? Is there good communication between the person and supervisors? Has the person been adequately trained? Is the software "user-friendly"?
If you answered "NO" to any of the questions in the Worker section, administrative issues which may be contributing to ergonomic risk. A review of training and other administrative policies is recommended.
A note regarding "ANSI/HFES 100-1988, American National Standard for Human Factors Engineering of Visual Display Terminal Workstations".
