Ergonomic Tips (08/04)
Using a computer chair
by John R. Chait D.C., drchait@hotmail.com
Member of the Sarasota Personal Computer Users Group, Inc.You should be able to sit comfortably in the chair, using as much of the chair back as possible for support. The lumbar support, built into or added on to the chair, should fit comfortably into the curve of your lower back, and your feet should be flat on the ground (use a footrest if necessary). The seat should be a comfortable size that allows at least one inch between your legs and either side of the chair, and supports your legs without applying undo pressure to the back of your knees.
Tips for using your chair
- Use a chair with a backrest that is easily adjustable and able to support the back in a variety of seated postures.
- Provide a chair that is sized to fit small or large users. Note: this is especially important if the chair is to be shared by several users.
- When sitting back, make any adjustments to the seat pan to reach a comfortable position. The seat pan should extend about an inch on both sides of your legs, and should not apply pressure to the back of your knees.
- Seat pan should be "depth" adjustable to adequately support taller users while allowing shorter users to sit with their back fully supported. The seat pan should provide support for most of the thigh without contact between the back of the user's knee and the front edge of the seat pan.
- If your armrests cannot be properly adjusted, or if they interfere with your computer positioning, remove them, or stop using them.
- There isn't a single static seated posture that should be used all of the time. It is a good idea to move around into different postures throughout the day to improve circulation and reduce muscle fatigue.
- Start with your seat at the highest setting and then adjust downward until your legs and feet feel comfortable, and angle of the back of your knees is open.
- Studies show that the best seated posture is a reclined posture of 100-110 degrees NOT the upright 90 degree posture that is often portrayed. In the recommended posture the chair starts to work for the body and there are significant decreases in postural muscle activity and in intervertebral disc pressure in the lumbar spine. Erect sitting is NOT relaxed, sustainable sitting, reclined sitting is.
- If chair mobility is important to help you to do your work then the chair should have at least a 5 leg base with casters that glide freely over the floor surface. You may also want to choose a chair that swivels easily.
- In the vast majority of situations you should not need a foot support to be able to sit comfortably on your chair? However, if you do need a foot support then choose a free-standing floor-mounted support that will allow you to rest your feet out in front of you in a comfortable manner.
Copyright 2004. This article is from the August 2004 issue of the Sarasota PC Monitor, the official monthly publication of the Sarasota Personal Computer Users Group, Inc., P.O. Box 15889, Sarasota, FL 34277-1889. Permission to reprint is granted only to other non-profit computer user groups, provided proper credit is given to the author and our publication. We would appreciate receiving a copy of the publication the reprint appears in, please send to above address, Attn: Editor. For further information about our group, email: admin@spcug.org/ Web: http://www.spcug.org/The Sarasota Personal Computer Users Group, Inc. has 1,100+ members and was established in 1982. We are members of the Assoc. of PC User Groups (APCUG), the Florida Assoc. of PC Users Groups, Inc., and we are members of the America Online Ambassador Program.
See http://www.spcug.org for all reviews from the Sarasota PC Monitor, go to the Newsletter Section.