In almost any aspect of daily life, people spend a great deal of time sitting down. Consider the following when choosing an office chair:
Seat height: The chair must not be so high that tissues in the back of the thigh are compressed and that the seat front edge does not reduce blood supply to the legs. This means that the front edge of the seat should be a bit lower than the distance from the floor to the underside of the thigh when seated.
Seat width: Fit is achieved when the seat width is wider than the width of the hips. This feature is important in ensuring that the worker will have flexibility to adjust their posture to relieve postural loading.
Seat depth: The back of the knee has relatively sensitive skin and little padding over the tendons, nerves and blood vessels; as a result, the seat depth should be slightly shorter than the worker’s upper thigh.
Seat angle: The seat angle should allow users to vary their posture forward and backward. This aids in ensuring good blood flow and to reduce loading on the spine and trunk muscles. It should also be lockable in various positions.
Trevor Schell is an ergonomist with the Occupational Health Clinics for Ontario Workers Inc., Sudbury Clinic.
Source: Trevor Schell, Northern Ontario Business; Dec, 2004 Copyright Northern Ontario Business Dec 2004