Assignment these dimensions should be used for designing
Stairways – Fall Prevention
Stairs with all types have been used since old times and
they have been always hazardous, so people fall from them, get hurt or even
they get killed. Most of the stairway falls happens because people lose balance.
Falling down from stairs can cause major life threatening injuries. The
stairway falling patients are having higher mortality rates than non-stairway-fall
patients like who fall down stairs like victims of motor vehicles accidents,
burns, other types of falls, suicide…etc. In fact millions of people are
treated for fall related injuries as stairways falls significantly cause a high
number of head-injured patients causing head trauma.
There are two very different types of causes, one factor
is the presence of floor obstacles falls are associated with dizziness and
fainting and other individual health factors most of such falls happens on
residential stairways. Researchers found out that most of the falls on stairs
are either slipping which is the primary cause of stair falls most of them
happens when people are walking down the stairs, another one is the absence of
handrails cause a large percentage of falls on stairs that result in injuries. Also,
unexpected location of stairs leads to many falls. For instance, stairs of just
one or two steps in a hallway or doorway can be very hazardous in particular.
Stair design, stair construction and maintenance, stair
placement, stair use, handrails are some of the accident encouraging factors
that contribute to stair falls.
Stairs especially with one or two steps cause a high
number of falls; this is a design feature. Thus, if you are planning to have an
extension or addition to a building you need to avoid differences in floor
heights that require these few steps. Treads
that are less than 9″ wide cause the highest number of missteps. Research
indicates the fact that the riser heights between 6″ and 8″and tread
widths of 10″ to 13″are most comfortable for most people.
Best stair dimensions are 7.2 inch riser heights with
either an 11 or 12 inch tread width. This these dimensions should be used for
designing stairs when considering remodeling or replacing a stairway. Sometimes
carpenters or contractors use old traditional building formulae for stairs
which can be not informed by human factors research, so a high attention should
be given if adding or replacing any stairs.
Construction and Maintenance:
One of the most important safety factors in the stair
construction is having a dimensional uniformity in the tread widths and riser
heights. A 1/4 inch difference between adjacent riser heights can cause an
accident. Existing stairs that do not have uniform dimensions cause real hazards,
such stairs should be replaced with correctly built stairs. Several reasons can
cause tripping or slipping hazards, so stairs should be kept clear and the
broken treads should be replaced or repaired immediately as well as any torn
carpets because they cause hazards. Accidents can be more preventable by adding
non-slip surfaces on treads. Broken lights over the stairs or a poorly lit
stair cause fall hazard, stairways shall be well lit.
Sometimes people are not aware of the presence of a stair
as it can be with the same color and texture as surrounding surfaces and they
can be poorly lit or marked which can cause difficulty to see. That can cause
people not to see that there is a change in the floor level. By adding visual
clues can give people attention to the stair or by changing floor materials and
colors for example can help people to identify the change in floor levels. Providing
handrail for one or two steps may look as it is unnecessary, but railing that
protrudes from the wall surface adjacent to the stair give visual clue of its
Stair handrails helps in preventing falls when a loss of
balance happens for users ascending or descending stairs; they help users to
quickly rebalance after slipping (Handrails Templer, 1992).
A research done by McKee and Verney (1988) recommends
that the height of the balustrade should be from 36 to 40 inches to be
effective in preventing falls with the descending stairs, however the height of
handrails developed by the national laws and state building codes require a
height of 30 to 34 inches. Generally, the Human Factors Design Handbook
suggests a high handrail of 34 inches overall the dimension falls within the
range required by most of the building codes.
The power grip optimizes the grip
forces in the hand while the round shaped handrails with a diameter of about
1.5 inches maximize grip forces for adults and a diameter of between 1.125 and
1.25 inches maximizes grip forces for children.
Rectangular shaped handrails are
usually easier to hold than round shaped railings, but these handrails require
a pinch grip which is the least effective grip to maximize the gripping forces
in the human hand.
Falls on the stairs kill and injure many people in the
United States each year by taking a human factors approach to stair design,
construction and maintenance, many falls can prevent falling.