Ergonomics
from my dentist's perspective
This
material has been produced by the Royal
Society of New Zealand (RSNZ) under contract to the Ministry
of Education. It has been written to assist teachers and schools
in their delivery of the technology and hangarau curriculum statements.
The project is jointly coordinated by personnel from the Technology
Education New Zealand (TENZ) and National Association of Māori
Mathematicians, Scientists and Technologists (NAMMSAT) networks.
Monitoring and evaluation of the material is carried out by a national
project advisory group.
|
The
dental chair
A visit to the dentist has changed a great deal over the years. While
improved procedures and equipment can undoubtedly enhance the experience
probably the most noticeable change for both patient and dentist is the
improvement to the dental chair. The patient can relax on a body supporting
reclining chair, while the dentist can be more efficient and productive
in a natural posture on a pivoting seat.
My dentist has a standard dental chair, manufactured in Germany, which
reclines fully keeping the angle of the back the same as in a sitting
position. The patient sits down and the chair is reclined in one gentle
movement to a height that is comfortable for the dentist when seated and
working at either the right side or at the back of the head. The dental
chair is ergonomically designed so that necessary equipment attached to
the dental chair (cuspidor, spitoon, three-way syringe, moving arm holding
trays of tools, and a bright light started manually or with a sensor)
is all within an arm's reach of wherever the dentist is sitting to perform
dental care. His body can lean forward or across as he sits upright on
his seat.
Patient
Needs
The patient needs to be relaxed and relatively still during the dental
process. Ergonomically designed features to encourage this are:
- Moulded shape to hold the pelvis in an upright position so
the spine falls into perfect alignment.
- A high-density padding upholstered in easy clean vinyl
- Seat tilt which moves with the body resulting in gentle lowering
and raising while keeping the back alignment.
- Gas lift height adjuster for effortless raising to the height
that is comfortable for the dentist.
|
Ergonomic problems identified by the dentist:
- The chair is "one size fits all" but this is not
ergonomically possible.
- Children/ short patients cannot be correctly positioned on
the seat with their heads on the headrest, therefore the dentist
has to lean further across.
- Tall patients are too long for the design and their feet dangle
over the edge, so the patient may not be completely comfortable
and relaxed.
|
These problems apply to people who are statistically in the extreme
10 percent of heights, and the chair has been designed for those in
the medial 90 percent of heights.
My dentist's seat has been ergonomically designed to consider the human
body and the job it is required for. The dentist can work with a naturally
balanced posture on a seat which reproduces the natural upright standing
position. The seat is adjusted to the dentist's personal height and
the patient's chair so there is no stress on the discs and the soft
tissue around the spine. The padded back rest can be adjusted up or
down, backwards or forwards to cater for a variety of individual body
sizes.
|
Lumber support protects the lower spine against unnecessary tension.
The ergonomically designed seat can be adjusted to a suitable height
so the dentist sits with feet on the ground, hips back into the seat
and thighs resting parallel to the ground. It is often necessary to
sit in the same position for several minutes to perform precision dental
care.
The dentist requires mobility to move between the bench and the chair
efficiently to perform a number of tasks efficiently and safely while
still maintaining correct posture. The chair has casters to assist with
easy movement in any direction so there is little strain on the body.
My dentist has certainly noted the difference between the old way of
standing to perform dental procedures and results of using today's ergonomically
designed seats. Back pain used to be a problem as dentists stood in
one position for considerable amounts of time hunched over patients.
Using a seat that has correct adjustments improves efficiency and has
removed body strain.
Ergonomically designed equipment has resulted in a visit to the dentist
that is enhanced for the patient. They are able to lie back and relax
on the body supporting reclining chair.
Background
information on ergonomics
The term ergonomics (Greek ergon, "work": nomos "laws") was first
used in Poland in l857. The modern discipline of ergonomics began in 1949
when the British navy explored human work problems and found that accidents
were not always caused by human error but by poorly designed controls.
Ergonomics, also known as human engineering or human factors engineering,
is designing machines, products and systems to maximise the safety, comfort,
and efficiency of the people who use them. Ergonomics allow human anatomy
to be the major environmental design consideration.
Average body measurements are critical for designing anatomically correct
seating. Specialists in anthropometry (the science of human dimensions)
examine the world's ergonomic databases to establish dimensions for
ergonomically designed equipment.
Ergonomists view people and the objects they use as one unit, ergonomic
designs blend the best abilities of people and objects. With a complete
picture of how humans interact with their environment, ergonomists develop
the best possible design for products and systems.
Note
This material has been adapted from the Matters of Principle Series
- a technology education resource produced by the Royal Society of New
Zealand in collaboration with The Institution of Professional Engineers
(IPENZ) and Technology Education New Zealand (TENZ). Further details
of publications in this series can be obtained by contacting:
publications@rsnz.govt.nz
