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Ergonomic standards and guidelines recommend several working postures –
sitting while reclining, upright, or in forward tilt; standing or alternating between
sitting and standing – recognizing that no one posture should be used for a
long period of time. A good ergonomic chair allows users to sit in these different
postures and provides features and adjustments with the ability to enhance
the comfort, productivity, and overall well-being of the occupant. Listed below
are Zody’s key ergonomic features and adjustments along with suggestions on
how to adjust the chair to maximize its potential for each individual user.
Back and Lumbar Support
The combination of the frame flex, mesh
construction, lumbar pad, lumbar pad spring
suspension and asymmetrical adjustment and
pelvic support make up the “PAL™” system’s
unsurpassed ability to provide comfortable
ergonomic support for a broad range of users.
Tension
Zody’s tension adjustment is a crank located
halfway back on the right side of the seat pan
(Figure 1). Adjusting the tension control regulates
the amount of resistance a user feels when leaning
back in the chair and the effort required to recline
the chair backwards. Forward (clockwise) rotation
increases the tension and backward (counterclockwise)
rotation decreases the tension. Zody’s
tension can be adjusted to accommodate users
of different body types and sizes and for different
work styles.
Torsional Movement
Zody was designed to have 2" of passive torsional
flex in the upper back. This means the backrest
follows the user as it moves, increasing mobility
and comfort when reaching sideways for objects.
Mesh Tension
Zody’s proprietary suspension mesh is a thin,
breathable 100% polyester woven fabric designed
to work in concert with the lumbar pad and pelvic
support. Several studies were completed to identify
appropriate upper and lower back mesh tensions
which provide users with continuous support.
Lumbar Support
When standing, the spine naturally forms an
“S-curve”, but when seated, the bottom of the
back tends to round out as the tailbone is curled
under causing the curvature to disappear. This
can cause lower back pain when seated, so it is
important to maintain the lumbar curvature
(lordosis) that occurs normally in the spine of the
lower back. Zody’s lumbar pad was designed so
it responds differently to people based on the
amount of support they desire. Its concentric rings
are different thicknesses and are interconnected
by relatively small flexible webs to ensure support
only where the user wants it.
The handles to adjust the lumbar are located on
the back of the chair (Figure 2). The lumbar pad
adjusts 4" vertically along the back of the user.
Pull up or down to adjust the height of the
lumbar pad. When adjusting the lumbar pad,
the height and shape of the lumbar pad should
coincide with the lumbar curve (“the small”) of
the user’s back. Rotate the handles up to increase
the amount of support and down to decrease
the amount of support. The handles can also be
adjusted independently of each other so users
can achieve varying amounts of support on
either the right or left side of their lower back.
Seat Pan Depth
The seat pan depth adjustment lever for Zody
is located under the seat pan on the left side
approximately 5" from the front of the seat
pan (Figure 5). Zody’s seat pan can be adjusted
3" in depth in order to accommodate a wider
range of the population. When sitting with the
knees bent at 90°, the seat pan should be
adjusted so it does not touch the back of the
knees or infringe upon the ability to bend the
knees to angles less than 90°. This provides the
thighs with support without creating pressure
behind the knees. Additionally, this allows the
user to sit back far enough in the seat pan to
use the lower portion of the backrest.
Back Stop
Zody’s backstop allows users to select an upright
position or limit the amount of recline (Figure 3).
This gives users the ability to select their preferred
posture and change postures throughout the
day. The back stop lever is located behind the
tension crank which is located halfway back
on the right side of the seat pan — to activate
it, recline and push down on the lever and to
release it, pull up on the lever. Zody has back
stops every 4° throughout the full recline (24°
of the chair.
Seat Pan Angle/Forward Tilt
The forward tilt option offers users the
opportunity to vary their posture throughout
the day. As with any posture, forward tilt is an
acceptable position to maintain for short periods.
Users shouldn’t maintain any one posture for
more than an hour. Excessive forward tilt may
cause users to slide out of the seat or put too
much weight onto their feet resulting in
prolonged static loading of leg muscles. The
forward tilt lever is located in front of the tension
crank which is located halfway back on the right
side of the seat pan (Figure 6). To activate it,
recline backwards in the seat while pushing
down on the lever and then lean forwards in
the chair. To release forward tilt, recline back
in the chair while pulling up on the lever.
Armrest Pivot
Pivoting the armrests allows users to position
the armrests based on the tasks they are
performing while still providing the user
with proper forearm support. To change the
pivot/angle of the armrest, grasp the armrest
cap and rotate the front of the armrest towards
your body or away from your body as needed
Ergonomic Standards/Guidelines
Based on the features of the chair model, Zody
meets the following ergonomic standards and
guidelines:
• BIFMA G1-2002: Ergonomics Guideline
for VDT (Visual Display Terminal)
Furniture Used in Office Work Spaces
• BSR/HFES 100-2002: Human Factors
Engineering of Computer Workstations,
draft standard for trial use
• CAN/CGSB 44.232-2002: Task Chairs for
Office Work with Visual Display Terminals
• CSA Z412-2000: Guideline on Office Ergonomics
Remember…..
Any adjustments made to the user’s chair need
to be made while taking into consideration
the workstation arrangement (height, knee
clearance, etc.) and the task being performed.
Users should adjust their chairs to a point where
they feel comfortable and to a position that
suits their personal needs or tasks. When that
position becomes uncomfortable (as it certainly
will over a long period), the chair should be
readjusted. Don’t be afraid to experiment. In fact,
constant fine-tuning chair adjustments will yield
the greatest benefits because as users adjust it, they
are moving, and movement is the key to a healthy
and ergonomically sound office environment.
For more information call 800.344.2600
©Haworth, Inc. 01.2006
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