Participatory ergonomics and an evaluation of a low-cost improvement effect on cleaners' working posture.

Abstract

Cleaning is a highly physically demanding job with a high frequency of awkward postures and working environments as contributing risk factors. Participatory ergonomics is a method in which end-users take an active role in identifying risk factors and solutions. The aim of this study was to apply the participatory ergonomics method to identify cleaning problems and to evaluate the effect of a low-cost improvement on cleaners' working postures in an office environment. The results show that the cleaning problem was identified, and the low-cost ergonomics solution suggested by the cleaners was implemented. Thus an improved working environment reduced the number of awkward cleaning postures and the Ovako Working Posture Analysis System (OWAS) action category for floor mopping decreased. It can be concluded that working in an improved environment can lead to better working postures which, in turn, leads to the cleaners' better health and better cleaning results.

Full text

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International Journal of Occupational Safety and Ergonomics (JOSE) 2005, Vol. 11, No. 2, 203–210
Correspondence and requests for offprints should be sent to Rupesh Kumar, Department of Human Work Sciences, Luleå University of
Technology, SE-971 87, Luleå, Sweden. E-mail: <Rupesh.Kumar@ltu.se>.
NOTES
Participatory Ergonomics and an Evaluation
of a Low-Cost Improvement Effect
on Cleaners’ Working Posture
Rupesh Kumar
Montakarn Chaikumarn
Jan Lundberg
Department of Human Work Sciences, Luleå University of Technology, Luleå, Sweden.
Cleaning is a highly physically demanding job with a high frequency of awkward postures and working
environments as contributing risk factors. Participatory ergonomics is a method in which end-users take
an active role in identifying risk factors and solutions. The aim of this study was to apply the participatory
ergonomics method to identify cleaning problems and to evaluate the effect of a low-cost improvement on
cleaners’ working postures in an office environment. The results show that the cleaning problem was identified,
and the low-cost ergonomics solution suggested by the cleaners was implemented. Thus an improved working
environment reduced the number of awkward cleaning postures and the Ovako Working Posture Analysis
System (OWAS) action category for floor mopping decreased. It can be concluded that working in an improved
environment can lead to better working postures which, in turn, leads to the cleaners’ better health and better
cleaning results.
participatory ergonomics cleaning OWAS postural analysis low-cost improvement
1. INTRODUCTION
Cleaning is considered a high physically demanding
job, resulting in high cardiovascular load [1, 2],
high frequency of awkward postures [3, 4] and, as
such, it is rated as a highly strenuous job [1, 2]. In
several studies the relationships between a poorly
designed workplace, poor working posture and
diseases of the musculoskeletal system have been
demonstrated [5, 6, 7].
According to Noro and Imada [8] participatory
ergonomics is a method in which its end-users take
an active role in the identification and analysis of risk
factors, as well as in the design and implementation
of ergonomics solutions. Participatory ergonomics
interventions have been associated with a decrease
in the incidence of musculoskeletal symptoms [9,
10], a decrease in work absenteeism [10] and an
improved psychosocial work environment [11].
Amongst the various ergonomics approaches,
participatory ergonomics is a popular one. In
participatory ergonomics workers are involved in
implementing ergonomics knowledge and principles
in their workplace, supported by their supervisors
and managers, in order to improve their working
conditions [12]. Several studies have shown the
success of problem identification and solution
through participatory ergonomics intervention [10,
13, 14].
The aim of this study was to use the participatory
ergonomics method to evaluate cleaning problems
and to evaluate the effect of a low-cost improvement

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204 R. KUMAR, M. CHAIKUMARN & J. LUNDBERG
JOSE 2005, Vol. 11, No. 2
on cleaners’ working postures in an office
environment.
2. METHOD
Twenty-three motivated professional female
cleaners from one university in Sweden took
part in a participatory workshop (PW). Their age
ranged from 24 to 54 years and the average length
of their work experience was 14 years. The PW
was carried out according to the following steps:
• Step 1: Definition of the framework/theme of
the PW,
• Step 2: Establishment of the goal,
• Step 3: Identification of the problem,
• Step 4: Development of a possible ergonomics
solution,
• Step 5: Implementation of the solution,
• Step 6: Evaluation.
The PW method is based on recommended
outlines for the process of participatory ergonomics
[15, 16, 17].
The theme of the PW, “Problems while
cleaning”, was defined in an active discussion of
all the cleaners. The conditions were flexible and
informal with access to refreshments and materials
for visualizing the output of the PW. The cleaners
sat in a U-shaped seat arrangement. The cleaners’
supervisor also participated as a neutral person
to guide the PW. Researchers facilitated the PW,
which took about 3 hrs.
The goal of the PW was to highlight all the
problems related to the present work situation
or conditions, which were experienced by the
cleaners and which they wanted to change.
Each participant briefly described a problem
she had experienced. The PW leader wrote it
down verbatim on a large sheet of paper with a
running number. This continued until no cleaner
could come up with any problem other than what
had already been expressed. This meant that the
cleaners had expressed all their criticisms.
After listing all the problems, each participant
ranked the three most critical problems from the
list and the PW leader ranked the listed problems
from the first to the last. The first ranked problem
was selected for developing a possible ergonomics
and economical solution.
The computer and electric cables were ranked
first by the cleaners because they made mopping
the floor difficult. Due to the cables on the floor,
the cleaners had to squat, lift the cables with one
hand, and mop the floor with the other. A possible
ergonomics solution to the problem, suggested by
the cleaners, was to fix the cables above the floor
by attaching them to the working table in such a
way that they did not lie on the floor in a scattered
fashion, or hang in the air (Figure 1).
Two hundred and twenty offices in one of the
university buildings were observed closely, and
it was found that 65% of those rooms had cables
sprawled on the floor. Out of the 220 office rooms,
six were selected for the purposes of the test; all of
them were used by university staff.
Figure 1. (a) Cables on the floor, (b) cables above the floor, attached to the working table.
(a)(b)

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PARTICIPATORY ERGONOMICS & LOW-COST IMPROVEMENT
JOSE 2005, Vol. 11, No. 2
Ten female cleaners, who had taken part in the
PW, participated in Tests 1 and 2, each of which
lasted 30 min per cleaner. In Test 1, they cleaned
a room with the cables on the floor using their
usual pace and style. Test 2 was carried out after
all cleaners finished Test 1. In Test 2, the cables
were fixed above the floor (they were attached to
the working tables) and the cleaners were asked
to perform the cleaning task in the same manner
as in the first test. One deciliter of dry sand was
used as cleaning dust on the floor in both tests so
that cleaners maintained their normal pace. Both
tests were recorded on videotape for task analysis
and postural analysis of cleaners with the Ovako
Working Posture Analysis System (OWAS)
method [18].
In the OWAS method there are about 252
posture combinations: work postures for the back,
arms, legs, and for carrying load, all of which are
assigned action codes [19, 20]. The four action
codes are defined as follows:
• Action category 1: change not required,
• Action category 2: change required in the near
future,
• Action category 3: change required as soon as
possible,
• Action category
immediately.
4: change required
After the second test, the videotapes were
analyzed with the WinOWAS computer software
[21] for analyzing working postures according to
the OWAS method. The random time interval for
coding a cleaning posture was 10 s.
3. RESULTS
3.1. Task Analysis
Task analysis was done by analyzing the videotapes
recorded while the cleaners cleaned a selected
room for the purposes of the tests. The task started
with pushing the cleaning cart into the office door,
and ended with closing the door (Figure 2).
As a result of task analysis, nine main activities
of the cleaning job were identified. Floor mopping
and wet dusting were the major ones (Figure 3).
Figure 2. Cleaning activities from task analysis.

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206 R. KUMAR, M. CHAIKUMARN & J. LUNDBERG
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3.2. Postural Analysis
The obtained data was analyzed according to the
different work phases (corresponding with task
analysis) for both tests, and the proportionate
share of postures for different work phases was
calculated in percentages.
The total number of OWAS observations
for each test was 1,370 for the 10 participating
cleaners. The proportionate share of postures of
different body parts was analyzed and categorized
into different action categories. After analyzing the
postures in Test 1, it was found that only mopping
and dusting proportions fell into categories 3 and
4. In Test 2, the floor mopping task did not fall
into categories 3 or 4 (Table 1).
The number of working postures for floor
mopping decreased from 36 to 33% of the total
working time after the cables were fixed above the
floor. The differences were found in the proportion
of the back, arms, and legs postures between Tests
1 and 2 during the floor mopping task (Table 2).
It was found that fixing the cables above the
floor affected the cleaners’ posture in the floor
mopping task only: the cleaners did not squat
while cleaning under the tables (Figure 4).
Figure 3. The proportion of cleaning activities: (a) with cables on the floor, (b) with cables above the
floor.
TABLE 1. OWAS Category for the Mopping Task Before and After Fixing Cables
Cleaning Task
Mopping
% of Working Time
OWAS CategoryCables on Floor
38
35
Cables Above Floor
40
60
—
—
1
2
3
4
4
24
Dusting
25
73
2
23
75
2
1
2
3
Notes. OWAS—Ovako Working Posture Analysis System.

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JOSE 2005, Vol. 11, No. 2
3.3. Quality of Floor Cleaning
It was observed that in Test 1, sand was still left
under the table where there were cables on the
floor. In Test 2, no sand was left on the floor after
the cables had been fixed above it.
4. DISCUSSION
In this study, the participatory ergonomics method
was successful in identifying ergonomics problems
at the workplace and possible ergonomics
solutions. The reason why workers’ participation
is important in problem solving is that workers
know their work and workplace better than
others, and they act as problem solvers [15, 22].
Further, participatory ergonomics enhances the
development of a two-way information flow
between a supervisor/researcher and the workers
(Figure 5), which facilitates ergonomic activities
for problem identification and ergonomics
solutions [23].
The low-cost change was implemented in the
office environment as suggested by the cleaners
TABLE 2. The OWAS Proportion of Back, Arms, and Legs Posture in the Floor Mopping Task in
Tests 1 and 2
Test 1
(Cables on Floor, %)
Back
Straight31
Bent32
Twisted 8
Bent and twisted29
Posture
Test 2
(Cables Above Floor, %)
31
37
9
23
Arms
Both below shoulder
One above shoulder
Both above shoulder
74
26
—
100
—
—
Legs
Standing on two legs
Standing on one leg
Sitting on two bent knees
Sitting on one bent knee
Kneeling
Walking
36
5
6
17
6
30
51
11
—
—
—
39
Notes. OWAS—Ovako Working Posture Analysis
Figure 4. Change of working posture during the floor mopping task: (a) with cables on the floor, (b)
with cables above the floor.