Seating Posture and Chair Adjustment
What is the Correct Seating Posture and Chair Adjustment
to Adopt to Minimize Risk Factors when Seated?
The chair should be adjusted to a height so that the thighs
of the user are parallel to the floor, or slightly
inclined towards the knee. The backrest should be
flush against the back of the user to provide support for
the lower back (including lumbar support). The angle
at the hips and knees should be slightly greater than 90° to
allow the feet to be slightly forward of the knee of the
user, under the desk. If required, a foot rest can be
added to support the foot and prevent plantarflexion
ankle. There should be at least 1.5" of space behind
the back of the leg to prevent the front edge of the seat
Arm rests (either on the chair or mounted on the work
surface) can also be helpful as they can assist in taking
the load of the weight of the arms off the shoulders.
This will remove a source of bad posture and relieve the
strain on shoulder and back muscles from supporting arm
Why is Improper Seating Posture and Chair Adjustment a
If adjustments or usage of the chair is incorrect,
circulation can become impeded and muscle fatigue and
cramping can occur.
How Close to Ideal does the Seating Posture and Chair
Adjustment have to be to avoid it being a Risk Factor?
There is a fair amount of variance in tolerance to poor
posture throughout the population. However,
individuals know when they are experiencing discomfort,
although they may not always realize it is the chair.
For some individuals, even being slightly 'off' is
sufficient to be a risk factor if it causes pain and
discomfort, but this is something that varies widely from
person to person.
What are the Symptoms of a Chair which is in the Wrong
Position or Improper Seating Posture?
Symptoms to look for include forced shifting of weight
distribution in the chair's seat to address lower back
pain/discomfort or pressure points on the seat or underside
of the thighs, or moving of legs to relief stiffness,
numbness, aches or pains.