Ergonomic Chairs
When people think of ergonomics,
chairs typically come to mind. Current technology runs the gamut, from
$1000+ executive office chairs to exotic Scandinavian Balans chairs (a
backless stool which you kneel in). Some feature articulating armrests,
keyboard support attaching to the armrests and head supports. The most
difficult issue relates to choosing a chair which fits your needs.
Ergonomics, Inc. has had great success with chairs offering a wide range
of adjustability. Adjustable chairs will not only accommodate people of
varying anatomical differences, they will allow for leg/hip/back
repositioning whenever pain or discomfort surfaces. An effective chair
will provide independent adjustments for:
 | seat height
| seat pan angle
| seat pan depth
| back rest height
| backrest angle
| armrest height
| optional inflatable lumbar pillows |
| | | | | |
In addition many chairs can be retrofitted with different cylinders for
sit / stand applications. The most important factor is to find a chair
that fits or will adjust to your anatomical needs. We have had good
success with the following chairs—each of which offer multiple-sized
backrests, seat pans and plenty of adjustment features.
Pros
Footrests are invaluable tools in an ergonomist's tool bag. They allow a
person to raise their seated height to overcome an excessively high
desktop or keyboard tray without compromising comprehensive back support.
The footrest encourages chair backrest use while providing support for the
lower extremities reducing inadvertent gluteal muscle contraction and
helping to maintain a good lumbar curve. Helping keep a good back
curvature and body positioning, footrests substantially reduce back pain
due to inadvertent bad posture.
Cons
The only shortcoming for most off-the-shelf footrests is still the
one-size-fits-all mentality. Specific dimensions of the footrest should be
determined by critical observation and measurement. Not just any footrest
height will fit everyone. Some will fit most folks. However like a chair
footrest height is highly individualized. A slight irritant is the small
size of most footrests which only measure about 12 by 18 inches. For
workers who tend to move around a lot this is inadequate. A really good
footrest should cover the entire area under your desk.
Applications
Footrests are great whenever the worker's feet do not rest firmly on the
ground after proper chair height is established. In a high seat (sit/stand
workstation) such as a high counter, a high seat footring should be
supplemented with a high footrest.
Fox Bay offers several good models. Prices range from about $50 for a
good standard adjustable to about $150 for a height adjustable unit.
| Sources: |
| Teos/Fox Bay |
800.430.6730 |
| Sunway(heated
footrests!) |
800.969.9708 |
Microsoft
Natural Keyboard
Pros
The MS natural keyboard separates the traditional keyboard into two
separate sections, oriented in a "V" and wave shape. This allows
the arms to hang freely at the sides while it promotes a
"natural" or neutral (straight) wrist posture when keying. The
MS natural keyboard keeps the center axis of the hand in line with the
center axis of the arm which minimizes at-risk wrist bending, whereas
straight keyboards force you to bend the wrists with small finger outward
(ulnar deviation). The MS Natural also has a built-in wrist support,
allowing shoulder and arm musculature to relax since the weight of
maintaining an outstretched arm is supported at the wrists / palms via the
built-in support.
Cons
The MS Natural keyboard does not fit on a keyboard support designed for a
traditional 101-key keyboard because of its size and features. Some find
the wrist / palm support too low still requiring excessive finger
extension, however an excellent after market wrist rest (SoftSpot tel.
800.228.8839) is available for about $20. The split keys also
inadvertently (to the untrained) promotes slight arm abduction (elbow
positioned away from the torso) which could impact someone with a shoulder
or elbow injury.
Applications
The MS Natural keyboard works very well for people who excessively bend
their wrists towards their small fingers (ulnar deviation) during
keyboarding. The split keys and "V" configuration has proven
beneficial in removing discomfort if the forearm/hands/wrists are forced
into specific at-risk postures with other keyboards, especially standard
types. It is important to distinguish application for wrists/hands as
opposed to shoulder or elbow issues.
Kinesis
Pros
The Kinesis keyboard also splits the traditional keyboard into two
sections. However, the Kinesis does not cant the keys, but places them in
a well with a curve to match the fingertips and finger reach. The key
wells are also separated by about 6 inches. This configuration promotes
both a neutral wrist posture while allowing the arms to easily rest
against the sides. Inside the curved wells, the keys reduce finger
extension associated with hitting keys further from home row.
The keyboard also provides built-in palm support and allows each key to
be re-mapped, offloading the stress associated with keying a particular
key to other stronger fingers. (e.g. key operation can be easily shifted
to the left hand or any finger on the right). Foot pedals are also
available to move select keying to the feet, especially applicable to
repetitive and at-risk continual keying of one specific key or set of
keys.
Cons
The Kinesis keyboard imbeds or doubles up several functions into the keys
which may frustrate some users with a learning curve. For example, the
numerical keypad functions as alphabetical letters when NumLock key is not
enabled.
Applications
The keyboard is great for people who excessively bend their wrists (at
risk postures with potential injury) towards their small fingers (ulnar
deviation) during keyboarding. Since keys/macros can be easily
re-programmed, this is an ideal keyboard for those experiencing tendonitis
Symptomology for repeatedly hitting the same key. For example, power 10
key operators repeatedly hitting the Enter key with the right small finger
can re-program this function to any other finger or even foot operation.
Pros
Attaching under the desk, keyboard trays effectively lower keyboard
height, typically reducing extended arm reaching and promoting neutral
wrist positioning during keyboard interaction. The more adjustment
features, the more likely a neutral upper extremity position can be found
with the proper adjustment. Some keyboard trays feature build-in arm
supports (a.k.a. wrist rests) which can reduce shoulder/upper back muscle
contraction resulting from keeping the arms outstretched.
Cons
Some under-desk keyboard trays will have a bulky adjusting/attachment
mechanism, which you can bang your knees against. Women often complain of
hosiery tears and men complain of bruised knees. Chair height adjustment
to properly effect leg/knee position is critical. Most current keyboard
trays will not accommodate the new, larger "V" keyboards such as
the Microsoft Natural. Some keyboard trays will inherently locate the user
8" to 16" from the desktop which may actually increase shoulder
flexion and associated extended reach problems, especially if a close
writing surface is not available or installed. Care should be taken to
train the user not to lean forward to view the monitor since the trays
place the monitor further away from the user.
Applications
The features of height, rotation, negative tilt and lateral sliding allow
the user to place the keyboard at a bio-mechanically effective (neutral)
position to reduce arm and shoulder discomfort and potential injury. The
larger keyboard trays also have room for a mouse or trackball next to the
keyboard addressing the mouse extended reach (mouse on the desktop)
problems.
We have had the most success with the keyboard trays with all
adjustments including the lateral sliding and adjustable built in wrist
supports.
| Sources: |
| Ergo Designs
(Local) |
360.352.1713 |
| Ergo Designs |
800.828.5779 |
| Teos/Fox Bay |
800.430.6730 |
| Sunway |
800.969.9708 |
| Workrite |
206.630.6700 |
| Ring King |
319.263.8144 |
Pros
Telephone headsets do a great job of eliminating inadvertent shoulder
elevation ("hunching") typically associated with keeping a
traditional telephone handset between the head and shoulder (telephone
neck). Current headsets attach to the head/ear in numerous ways (e.g.
over-the-head, over-the-ear, cordless), accommodating most telephone user
likes and dislikes. A study funded by a headset manufacturer (Plantronics)
revealed headsets increase productivity (allowing efficient data entry
during use) and reduce neck, shoulder and upper back muscle contraction.
Cons
Not all headsets work with all telephone systems—some produce quite a
bit of static. Also telephone headsets can be spendy: $125 - $500.
Applications
Some feature different ear pieces and head bands—application is
subjective according to user preference and existing phone system
compatibility. All help alleviate painful "telephone neck" of
"power users" such as executives, receptionists, customer
representatives, sales/support staff and telemarketers.
| Sources: |
| ACS |
800.262.2480 |
| GN Netcom |
800.222.5424 |
| Hello Direct |
800.444.3556 |
| Plantronics |
800.538.0748 |
| UNEX |
800.262.2480 |
| VXI |
800.222.5424 |
Kensington Turbo Mouse
Pros
The Kensington Turbo Mouse trackball is configured with a large (3 inch
diameter) ball centrally located on the unit's top surface (half the ball
surface is exposed for finer palm control). One control key is located on
each side of the ball (right and left) and can be reprogrammed for left or
right handed control. Kensington Turbo Mouse has menu driven software
which allows the user a myriad of control options for each key. Keys can
be assigned to automatically drag-lock, double click, etc. Cursor control
speed and arrow size can also be programmed.
The Turbo Mouse is better than the standard mouse for most mouse
intensive tasks in eliminating arm extension and movement. When full arm
extension is reduced, specific shoulder discomfort is eliminated. The
Turbo Mouse also eliminates the constant gripping postures often used on a
standard mouse, successfully addressing hand and forearm muscular
contraction.
Cons
The Turbo Mouse's large ball is not for every user and may prove
cumbersome for users with smaller hands.
Applications
The Turbo Mouse is a particularly good device because of its overall
versatility. Its ambidextrous configuration and range of customization
make this device ideally suited for most biomechanical and task
performance requirements. Price is about $115.
Mouse-Trak
Pros
The Mouse-Trakk trackball has a large 3.5 inch trackball centrally located
in the upper half of the unit's large convex surface. We found it provides
a good comfortable hand/palm rest during use. Approximately 1/4 of the
ball is exposed with long control keys located on the top (front), left
and right sides. Menu driven software allows keys to be remapped and
programmed, and a roller located above the trackball simplifies character
"highlighting". The Mouse-Trakk is available for Macintosh
platforms and is the only trackball available for Sun workstation
platforms making it a very versatile input device. It is also very cost
effective—$35.
Cons
In some programs (CAD) the ball does not always translate to finite cursor
control (small ball rotation may not yield effective cursor movement),
which may not be subjectively suitable for some "power" mouse
operators
Applications
Mouse-Trakk is well suited for most computer users, especially non-mouse
intensive users or those who have severe hand / wrist / arm pain from the
standard mouse or other trackballs. It can be used either right or left
handed and very effectively addresses the need for support at the hand
with its exceptional hand / palm rest configuration.
Alps Glidepoint
Pros
An alternative to mouse and trackball systems, the Glidepoint consists of
a touch pad and two control keys located centrally below the pad. Cursor
movement is facilitated via "dragging" the finger across the
touchpad surface (no ball or mouse to manipulate). Menu driven software
allows a variety of customization options, including gain ratio (how fast
/ far the cursor moves across the screen with finger movement across the
touchpad) and control key location / function.
The Glidepoint is a clever device which greatly reduces biomechanical
strain during cursor manipulation. its small dimension and versatility
allows it to be easily located in the workstation (close to the keyboard)
and switched between the left and right hands. It is a useful system when
manipulating through Windows, particularly due to the pressure sensitive
touchpad (e.g. quickly "popping" the touchpad is equivalent to
pressing a control key).
Cons
Because of limited system sensitivity, the Glidepoint is not a practical
solution for "mouse-intensive" task performance (e.g. computer
drafting). The small size of the system (location of control keys relative
to touchpad) has also proven cumbersome for operators with large hands.
Applications
The Glidepoint is a very good alternative to computer users who have (or
will) developed grip or hand problems specific to mouse usage
(tendonitis). If the hands/wrists are supported properly (critical) the
Glidepoint allows computing in Windows for those who bio-mechanically
cannot use a trackball or mouse. Properly situated with good hand/wrist
positioning, it effectively offloads many of the positions and postures
which can lead to biomechanical breakdown and
future injury. Cost: $120
PC Visor is
like a baseball cap for monitors. It is designed to perform a task
anti-glare screens can not—eliminate screen washout from direct,
indirect, or bounced light.
Pros
The PC Visor shades the monitor screen from direct washout (caused by
light), insuring good viewing contrast. It sharpens images, reduces
reflection and glare and improves readability.
One of the unique features of the PC Visor is the ability to angle the
sides inward providing a "viewing tunnel". This offers greater
privacy for sensitive information, as well as maximum blockage of all
light sources.
Ergonomically, the visor reduces eyestrain associated with poor monitor
contrast. Productivity is enhanced simply because information displayed is
more readable.
Cons
The PC Visor only comes in a special non-reflective black plastic—may
not fit office decor.
Applications
Appropriate for all monitors located in settings with "normal"
lighting levels. Especially useful for monitors located near windows. Also
good for monitors who reflect hot spots of light (overhead projectors)
from behind the viewer.
| Sources: |
| PC Visor |
360.427.5779 |
