Ergonomic Seating

12/05/2001 |

How to select chairs that fit people and their work

By Edward A. Metzger

Ergonomics are a leading consideration in creating offices that are safe and comfortable. Employing ergonomic principles can increase productivity, reduce occupational injuries, reduce lost time, and lower operating costs.

Seating is critical when individuals spend most of their day seated at a desk or workstation. Individuals use nearly 100 muscles to balance in a seated position, and inadequate support can place fatiguing strain on back, leg, and stomach muscles.

Ergonomic seating acts as a natural extension of the body, providing the balanced support that helps maintain proper posture. Ergonomic seating supports the torso and hips so that minimal force is exerted in holding the torso stable. This support reduces fatigue from highly repetitive operations or concentrated computer work, and reduces the risk of musculoskeletal and cumulative trauma disorders.

People have differences and limitations created by their height, strength, and other factors. Their work is done on surfaces of differing heights. One of the most important benefits of ergonomic seating is its ability to adapt quickly and easily to these differences.

The purchase of seating can be complicated by the word "ergonomic." Some outlets apply it to chairs that offer few, if any, ergonomic benefits. These chairs fail to offer the balanced support required for long periods of sitting and/or the adjustability to adapt to different users and their tasks.

Adjustability, combined with basic ergonomic support features, should be the focus of evaluating and selecting chairs. Adjustability usually eliminates the need for a different chair model for each person (although individuals with special physical needs may require a specific type of chair). Concentrate the selection process on a short list of models that offer:

• Backrest with lumbar support to help maintain the back's natural S-curve (however, such support might not be appropriate for an individual with atypical spinal curvature).
• Backrest height adjustability, enabling the lumbar support to fit the back.
• Seat pan that is at least an inch wider than the user's hips and thighs on either side, with seat depth to provide room between the lumbar support and hips (for maximum comfort, the seat should have a waterfall front and sufficient cushioning to prevent feeling the seat board).
• Seat tilt adjustability, to promote even weight distribution and proper torso-to-thigh angle.
• Seat height adjustability, to help assure that the chair's height will fit the user(s) and their tasks.

An ergonomic chair should have controls that enable a seated user to quickly and easily adjust both the seat and backrest. Ergonomists and knowledgeable manufacturers' representatives can provide guidance on the appropriate seat height range for an office application.

The evaluation process should include manufacturers' capabilities. A manufacturer should offer:

• Chairs with modular construction, enabling interchange of components as needed.
• An extensive selection of options - including armrests, controls, footrests, casters, and glides - for customizing basic chairs to specific applications.
• Full-service support, including retrofitting at the office site, to ensure satisfaction with new chairs.
• Warranty coverage of chairs and components, along with the credibility and experience to back warranty guarantees.

To summarize, shop for chair adjustability, modular construction, and option availability. Compare manufacturers' warranties. And work with an experienced, full-service ergonomic seating manufacturer to achieve the goal of good value per dollars spent.

Edward A. Metzger is vice president, Sales, at Waterville, OH-based BioFit Engineered Products (www.biofit.com).


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