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BIFMA's New Ergonomic Guideline

By Richard P. Driscoll

Historically, the contract furniture industry has experienced relatively few controversial issues. However, with the repeal of OSHA’s 2001 Ergonomics Program Standard, facility managers have been given ambiguous direction regarding the prevention of musculoskeletal disorders in the workplace.

One organization that has stepped in to propose a possible solution to the ergonomics question is the Business and Institutional Furniture Manufacturer’s Association (BIFMA). This not-for-profit trade associ-ation of North American furniture manufacturers, suppliers, and service members promotes the growth of the office furniture industry by providing market focused services, including the development of standards.

BIFMA produced its first standard, X5.1 General Purpose Office Seating, in 1978. (Since then, there have been several revisions to X5.1, and a 2002 edition is anticipated by the end of this year.) The list of BIFMA standards has grown to include lateral files, vertical files, desk/table products, panel systems, and even products for the home office. These standards are voluntary minimum performance and safety initiatives.

Coming To Conclusions
More than 10 years ago, the international organization for standards (better known as ISO) published a 17-part international standard identified as ISO 9241 Ergonomic Requirements For Office Work With Visual Display Terminals (VDTs). Updated in 1992, ISO 9241-3 contained some relevant design requirements and recommendations that applied to positioning the display. Revised once again in 1998, the section entitled Part 5: Workstation Layout and Postural Requirements contained ergonomic guiding principles and design requirements, but no dimensions or ranges for office work with VDTs.

Historically, BIFMA supported and referred to the voluntary U.S. Standard ANSI/HFS 100-1988 American National Standard for Human Factors Engineering of Visual Display Terminal Workstations as a guide for ergonomics in the workplace. This standard has been undergoing revisions through the 1990s and continues today.

With the HFS 100 document in a state of revision, there were no documents to guide BIFMA members in the application of relevant ISO principles and requirements to the dimensions and adjustment ranges of VDT furniture. Consequently, in July of 1999, the BIFMA Ergonomics Subcommittee began development work on a guideline for furniture intended for computer use in the U.S. and Canada. The goal was to provide useful guidance for the contract furniture industry in the area of ergonomics without conflicting or competing with another standard or standards developing organization.

In January 2002, BIFMA released its Ergonomics Guideline For VDT for Furniture Used in Office Work Spaces (BIFMA G1-2002). Intended users of the new standard include furniture manufacturers, dealers, and their clients; facility and material managers; purchasing managers; interior designers/architects/specifiers/industrial designers; ergonomists; testing facilities; and other professionals involved in designing, manufacturing, specifying, qualifying, and purchasing of VDT furniture.

Guideline Resources
In developing the Ergonomics Guideline, BIFMA adopted NATICK/TR-89/044, 1988 Anthropometric Survey Of U.S. Army Personnel as the sole source of relevant body dimensions. Recommended work space dimensions and ranges are based on meeting the requirements of the relevant fifth percentile female through the 95th percentile male body dimensions in an upright posture.

While the population measured by NATICK does not precisely reflect the office working population of North America, it was the most comprehensive database available during the development period of the guideline. The measurement methods are consistent with the anthropometric measurement methods described in ISO 7250, Basic Human Body Measurements For Technological Design. If another database becomes available, the users of the guideline are encouraged to apply such information.

The BIFMA Guideline acknowledges, however, there is no single correct working posture. Alternate postures may result in dimensional requirements that differ from those contained in the guideline.

Guideline Format
Released in January 2002, BIFMA International’s ergonomic guideline is an extensive document that includes several comprehensive tables, graphs, illustrations, and charts. Section 1 of the guideline contains the foreword, followed by an overview of the scope, conformance criteria, limitations, definitions, and general considerations of the standard.

Two of the larger, more complex portions of the standard–Section 7: The Work Chair and Section 8: Work Surfaces–are subdivided by significant parameters. The format for each of the parameters is as follows:
• Sub-Section Title (for example, seat height, seat depth, and other specifics);
• ISO 9241-5 Related Quote and Reference;
• Relevant Body Dimension (name of anthropometric measurement);
• Why something like seat height, for example, is important;
• Discussion;
• Recommended dimensions/ranges; and
• Ultimate Test for Fit (UTFF). (For a more detailed description of UTFF, see the explanation that follows.)

Section 9 contains additional information, including relevant quotes from ISO 9241-5 that may influence comfort, performance, and safety. It also contains a table of relevant NATICK data and a table of the recommended dimensions and ranges for each chair and work surface parameter. Section 10 lists recommended reading sources.

Revision Cycle
During the development of the guideline, the BIFMA Ergonomics Document Drafting Team–chaired by Lucy Hart, CCPE–was key in the formulation of the standard. Additional direction was provided by Doug Kokot of Steelcase, Inc. and other BIFMA members.

The BIFMA Engineering Committee will maintain responsibility for the development and maintenance of BIFMA standards, guidelines, and other technical documents.

BIFMA tentatively plans to revise the guideline every five years. This timetable is not fixed, and in the event of new technology, research, or an update of relevant ISO 9241 standards, the revisions may be undertaken sooner. Users are encouraged to contact BIFMA International regarding any comments they may have relative to the guideline.

Driscoll is technical services manager of Grand Rapids, MI-based BIFMA International. He directs and coordinates the BIFMA Engineering committee and its numerous subcommittees. For more information on BIFMA’s ergonomic standard, call Driscoll at (616) 285-3963 or e-mail rdriscol@bifma.org.

Was this article informative? What kind of ergonomic program do you have in your facility? Share your comments by writing to schwartz@groupc.com.

BIFMA Ultimate Test For Fit (UTFF)

What follows is a detailed explanation of UTFF for work chairs and surfaces. Parenthetical numbers following each item indicate corresponding subdivisions in the guidelines.

The Work Chair
Seat Height (7.1). Users should be able to sit with their feet comfortably on the floor or footrest without undue pressure on the underside of the thighs. The thigh-to-torso angle should not be less than 90°.

Seat Depth (7.2).Users should be able to sit in the chair without undue pressure against the back of the knees, their back properly supported by the backrest and with adequate buttock and thigh support.

Seat Width (7.3). The seat should be wider than the hip breadth of the user with allowance for movement and clothing. The seat width should not limit the ability to use the armrests comfortably.

Seat Pan Angle (7.4). This should allow users to support their feet on the floor or footrest. They should not cause the user’s torso-to-thigh angle to be less than 90°. Forward seat pan angles should not cause users to shift excessive weight to their feet or experience the sensation of sliding out of the chair.

Back Support (7.5)
• Seat Backrest Height (7.5.1). All backrests should provide adequate lumbar support and buttocks clearance. For tasks requiring upper body mobility, the backrest should not interfere with the user’s movement. For users who prefer reclining postures or greater upper back support, the back height should provide support for the shoulder blades.
• Backrest Width (7.5.2). The width of the backrest should provide adequate support for the curvature of the user’s back without causing localized pressure points.
• Lumbar Support (7.5.3). The height and shape of the lumbar support should coincide with the lumbar curve ("the small") of the user’s back. The support should be firm, but not cause localized pressure points.

Movements of the Seat Pan and Back Support (7.6). The user should be able to sit in a position where the torso-to-thigh angle is equal to or greater than 90°. The seat and backrest angles should accommodate the varying postures assumed by the user throughout the day.

Arm Support (7.7)
• Armrest Height (7.7.1). This should allow users to sit in a variety of postures while supporting their forearms and/or elbows in a manner that avoids lifting the shoulders (armrests too high) or leaning to the side to reach the armrest (armrests too low). The armrest height should allow accessibility to, and performance of, tasks.
• Armrest Length (7.7.2). The length of the armrest should allow users to sit close enough to the work surface to perform their tasks while maintaining contact with the backrest.
• Inside Distance Between Armrests (7.7.3). Armrests should allow users to sit in a variety of postures while supporting their forearms in a manner that avoids lifting the shoulders and/or excessive outward positioning of the elbows. Armrests should allow accessibility to, and performance of, tasks. The inside distance between the armrests should allow the user to enter and exit the chair easily. The hips should comfortably fit between the armrests or supports.

Work Surfaces
Height Clearance for Legs–Sitting (8.1.1). When centered on their task, users should be able to fit their legs in the space without contacting the support structure. The space should be adequate to permit users to get close to their work surface while allowing freedom of movement.

Depth Clearance for Knees–Sitting (8.1.2). Users should be able to fit their knees in the space provided under the work surface without obstruction. There should be enough space to allow users to get close to their work surface while providing some freedom of movement.

Width Clearance for Thighs–Sitting (8.1.3). Users should be able to fit their thighs in the space. The space should be enough to allow for some freedom of movement.

Height Clearance at Foot Level–Sitting (8.1.4). When centered on their task, users should be able to sit close to the work surface in an upright posture without obstruction at foot level.

Depth Clearance at Foot Level–Sitting (8.1.5). Users should be able to fit their legs in the space provided under the work surface without obstruction. There should be enough space to permit users to get close to their work surface while allowing freedom of foot movement and/or postural changes.

Clearances Under Work Surfaces for Standing Work (8.2)
• Height Clearance at Foot Level–Standing (8.2.1). When centered on the task, users should be able to stand close to the work surface without obstruction at foot level.
• Depth Clearance at Foot Level–Standing (8.2.2). When centered on their task, users should be able to stand close to the work surface without obstruction at foot level.
• Width Clearance at Foot Level–Standing (8.2.3). When centered on their task, users should be able to stand close to the work surface without obstruction.

Support Surface Heights for Input Devices and VDTs (8.3)
• Support Surface Height for Input Devices–Sitting (8.3.1). Users should be able to sit with adequate clearance for the legs, with the shoulders, elbows, and wrists at near neutral positions. In some cases, compromises in posture will be necessary.
• Support Surface Height for VDT–Sitting (8.3.2). The support surface should allow the VDT to be at a height that permits the user to view the entire VDT screen at a position between horizontal eye level and 60° below eye level, preferably at a position between 20° and 50° below eye level. The top of the screen should not be closer to the eyes than the bottom of the screen. Users should be able to move their legs under the support surface without obstruction.
• Support Surface Height for Input Devices–Standing (8.3.3). Users should be able to stand erect at the input device support surface with adequate clearance for their feet. The shoulders, elbows, and wrists should be at near neutral positions.
• Support Surface Height for VDT–Standing (8.3.4). The support surface should be at a height that allows the user to view the entire VDT screen at a position between horizontal eye level and 60° below eye level, preferably at a position between 15° and 45° below eye level. The top of the screen should not be closer to the eyes than the bottom of the screen. The user should be able to stand close to the support surface.

Support Surface Depth for VDT–Sitting or Standing (8.4). With the user seated (or standing, as appropriate) in a normal posture, the viewing distance should be greater than 40 cm (15.7").