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Seat and Back Adjustment

1. Seat Height

Using the floor as a basis for all adjustments to the chair begin with setting the height of the seat. Seat height should be set so that the workers thigh has a very slight downward angle from the hip to the knee.

2. Seat Pitch

The pitch of the seat should be set so that the worker feels support evenly all along the back of their legs from the buttock to the back of the thigh.

3. Back Height

Nearly all chairs have some lumbar support. The height of the back should be adjusted so as to apply the lumbar support curve to the corresponding lumbar curve of the worker. Be careful not to allow the lumbar support to be applied too low. If the chair back is positioned too low it may cause a forward rotation of the pelvis. The sensation the user feels is similar to excessive lumbar support. Try moving the back up and down to insure there is proper mating of the lumbar support and the user's lumbar curve.

4. Back Pitch

This adjustment is similar to the seat adjustment. The pitch should be adjusted to insure even support up and down the back with support being applied to the largest portion of the back while in a working posture. The pivot point of the back pitch adjustment is behind the seat. When the support is greater at the lumbar the chair back pitch should be moved toward the user to balance the support.