Introduction
Workelated Musculoskeletal Disorders
(WRMSDs) is an umbrella term for conditions thought to be caused by exposures
in the workplace [1]. It is often referred to as overuse syndrome, repetitive
strain injury or cumulative trauma disorder [2]. It is a significant
contemporary occupational health problem estimated to affect millions of
workers around the world annually [3]. WRMSDs are an important cause of
morbidity and disability in many occupational populations [4]. It is prevalent
among people who perform repetitive jobs and constitutes major health problems
in industrial Countries [5-8].
The increased volume of WRMSDs
and injuries and their profound
economic impact in the workplace have led to studies aimed at identifying the
essential risk factors and to establish sound intervention strategies [9].
Previous studies have revealed that WRMSDs among Welders are caused, aggravated
or precipitated through their need to exert undesirable force, use
uncomfortable hand grips, or adopt static awkward postures in the workplace
coupled with continuous repetitive work and insufficient rest or recovery among
workers [1, 6, 10].
The return to the workplace of
individuals affected by WRMSDs represents a critical problem in work settings
that feature a multitude of tasks which are liable to biomechanical strain of
the body [11-14]. Therefore, WRMSDs are precipitated by increased muscle
tension, heightened awareness of normal or increased sensory nerve input, and
anxiety driven introspection. This disorder has both physical and psychological
causes [15-19].
The origins of WRMSDs are assumed
to be multifactorial, with the implication that several risk factors can
contribute to its development. Evidence shows that neck
flexion and sitting
are physical risk
factors for neck
pain among welders, whereas high quantitative job demands, low authority
over decisions, low skill discretion, and poor social support by colleagues are
important work-related psychosocial risk factors among them [20-21]. However, topographic
distribution of WRMSDs among professional welders is still unclear. Although the input of WRMSDs on functional
performance of welders has not been well documented, it has been opined that
physical work factors may or may not be associated with prognosis in WRMSDs
[22-23].
Therefore, there is need for a
study on prevalence, pattern and input of WRMSDs on functional performance in
various occupational groups. This study investigated the prevalence, pattern
and impact of WRMSDs on functional efficiency among welders in a rural-urban
setting in Nigeria.
Materials and Methods
This
cross sectional survey involved 177 Welders in a rural-urban area in Nigeria
between January and July, 2011. This research was approved by the research
ethics committee of the Lagos University Teaching Hospital, Lagos, Nigeria. The
informed consent from the participants was obtained before participating in the
study. A total of 177 Welders in
Alimosho Local Government Area of Lagos State, Nigeria participated in this
study. Respondents were systematically selected from a registry list of the
register of their professional association. Those who had less than one year
working experience were excluded. The instrument used for this study was a
questionnaire adopted from Maastricht musculoskeletal questionnaire [6]. The
Maastricht musculoskeletal questionnaire was modified to include some items on
functional performance and other items that are specific to a job like welding.
The questionnaire was divided into four sections (A to D). Section A comprised
of socio-demographic data and job history. Section B comprised of information
on body posture, job demand, work environment, and level of social interaction.
Section C comprised of information on prevalence, pattern, and causes of
musculoskeletal pain, while section D comprised of information on effect of
musculoskeletal pain on job performance, leisure and family role. A total of 62
questions made up the questionnaire. The items in the questionnaire were
designed using the responses from the participants in the Maastricht upper
extremity questionnaire. The questionnaire was then distributed to 10
Physiotherapists, 2 Biostatistician, 2 Occupational Therapists, and 2
Orthopedic surgeons for content validity. The suggested corrections were made and
the revised questionnaire was administered to 30 welders in Lagos other than
the intended research area for measuring test-retest reliability (r=0.92). Participants
were selected through the authorities of the Welders’ Association. We adopted
to recruit them through this authorities as it is mandatory for every member to
attend at least a meeting within a month. The permission of the authorities of
the association was obtained as well as the written informed consent of each
participant. The researcher attended all weekly meetings of the association
where the questionnaires were distributed to the participant. Each participant
completed and returned the questionnaire within the meeting periods. Descriptive statistics methods including mean, standard
deviation and percentage were used to summarize the data. Chi-square test was
used to find the impact of WMSDs on functional performance.
Results
This study involved 177 (all
male) welders in Alimosho Local Government Area of Lagos State. Their age
ranged between 20-61 years with a mean of 36.46±10.02 years. One hundred and
thirty-six (76.8%) participants were married, 34 (19.2%) were single while 7
(4%) were divorced. One hundred and twelve (63.6%) participants had primary
education while only one (0.6%) had university education. Eighty-seven (49.7%) were supervisors at
work, 62 (35.4%) were labourer, while 21 (12%) were join men. The years of working
experience ranged between 1-42 years, with a mean 14.31±9.93 years and mode of
4 years. Their average working hours per day ranged between 5-12 hours with
mean of 7.31±1.40 (Table 1).
Most participants, (78, 44.1%),
worked best bending from the back, while 31 (17.5%) worked best standing
upright (Figure 1).
Forty-three
participants reported (24.3%) always keeping their back straight at work, while
six of them (3.4%) never maintain straight back at work. Sixty-five (36.7%) of
participants always bent for long hours in one position, while six (3.4%)
declared that never having to bend their backs for long time.
Table 1: Some socio-demographic
characteristics of the participants
|
Variables
|
Frequency (n)
|
Percentage (n)
|
|
Age Group
- 20-29
- 30-39
- 40-49
- 50-59
- 60 and above
Educational qualification
|
49
67
37
18
6
|
27.7
37.9
20.9
10.2
3.4
|
|
- Non-formal
|
34
|
19.4
|
|
- Primary
|
112
|
63.6
|
|
- Secondary
|
21
|
11.9
|
|
- Technical
|
4
|
2.3
|
|
- Polytechnic
|
4
|
2.3
|
|
- University
|
1
|
0.6
|
|
Level of work involvement
|
|
|
|
- Apprentice
|
5
|
2.9
|
|
- Join man
|
21
|
12
|
|
- Labourer
|
62
|
35.4
|
|
- Supervisor
Marital Status
- Single
- Married
- Divorced
|
87
34
136
7
|
49.7
19.0
77.0
4.0
|
Figure
1: Distribution of participants based on their work posture
More than half (52.5%). always
lifted heavy objects at work while few (2.8%) never lifted heavy objects at
work. More than 38% of participants were used to work up to two hours at a
level higher than their shoulder while
about 14% (n=25) never work two hours at a level higher than their shoulder at work. Thirty five percent
always sit in awkward postures at work while few of them (4%) never sit in an
awkward posture at work. About 52% always found their job physically
exhausting, while only three (1.7%) welders never found their job physically
exhausting (Table 2).
Sixty-seven (38.1%) always worked
under extensive pressure while nine (5.1%) never worked under extensive
pressure. Majority (65.5%) always found their co-workers friendly while a few
(0.6%) never found them friendly. Eighty (45.7%) always took extra hours to
finish their jobs while five (2.9%) never required extra hours to finish their
jobs. Seventy-one (40.1%) always found their work task difficult, while two
(1.1%) always found it easy. Eighty-four (47.5%) participants always found
their work environment "good" while only two (1.1%) never found their
work environment "good". One-hundred and thirty (73.4%) were always
exposed to welding arc light while five (2.8%) were seldom exposed to welding
arc light. Twenty-seven (15.3%) participants always worked for a long time
without resting while sixty-one (34.5%) never worked for a long time without
resting. Forty-eight (27.1%) always found it difficult to concentrate on their
jobs, and twenty (11.3%) never found it difficult to concentrate on their jobs.
One-hundred and one (57.1%) participants always worked beyond their normal
working hours daily, and only two (1.1%) never worked beyond the normal working
hours (Table 2).
A total
of 126 (71.2%) participants did not have musculoskeletal complaints at that
time, while 51 (28.8%) of them had musculoskeletal complaints. Also, 55 (31.1%)
did not have musculoskeletal complaints within the last 12 months, while 122
(68.6%) participants had complaints. Among them, 105 (87.5%) of the
musculoskeletal complaints were caused by job activities, five (4.2%) of the
participant did not know the cause, eight of them (6.7%) stated that it was
caused by accident outside the work, and two (1.7%) stated that it had been caused
by accident at work (Table 3). Respondents who reported musculoskeletal
problems at some stage during their work were asked to choose specific areas
and were asked if the pain disappeared after a short rest or not. Forty-six (38%)
had neck pain and forty- eight (39.3%) had shoulder pain. Upper arm pain was
reported by 25 (20.5%), elbow pain and lower back pain was reported among
9(7.3%) and 49 (60.2%), respectively. The number of participants who had complained
during the past one year were 116 (96.7%). Duration that they were not able to
perform their job due to musculoskeletal problems ranged between 1-14 days.
About 41% of injured participants had been treated by a physician (n=50).
Table3:
Prevalence and causes of musculoskeletal disorder in participants
|
Variables
|
n
|
%
|
|
Prevalence
|
|
|
|
- Musculoskeletal
complain now (no)
|
126
|
71.2
|
|
- Musculoskeletal complain now (yes)
|
51
|
28.8
|
|
- Musculoskeletal complain in last
12month (no)
|
55
|
31.1
|
|
- Musculoskeletal
complain in last 12month (yes)
|
122
|
68.9
|
|
Cause of complain
|
|
|
|
- My job activities
|
105
|
87.5
|
|
- I don’t know
|
5
|
4.2
|
|
- Accident outside work
|
8
|
6.7
|
|
- Accident at work
|
2
|
1.7
|
Twenty-three
(19.4%) had received education on how to prevent musculoskeletal pain of which
only 5 (21.7%) studied it. Seventeen participants (73.9%) were educated by a
physician. One hundred and eleven (91.7%) people had received treatment for
complains, of which 37 (32.7%) used medication, 3 (2.7%) had operation, 54
(47.8%) used self-medication while 19 (16.8%) preferred traditional remedies.
Thirty-two (26.2%) had lost a job before, nine (7.4%) had changed their job and
work efficiency of seventy-eight (63.9%) was reduced. Twenty of them (16.4%)
could no longer do their work during the past of year. Forty-two (34.4%) could
not work, 67 (54.9%) participant’s activities were hindered in their functional
performance at work and in 44 (36.1%) their leisure activities were hindered,
in 45 of them (37.2%) social relationship with other people were hindered, 34
(28.1%) sexual activities were hindered and 24 (19.7%) religious activities
were hindered. Work-related musculoskeletal disorders had significant negative
effect on functional performances, family role and leisure activities of the
participants.
Discussion
The
purpose of this study was to investigate work-related musculoskeletal problems experienced
by welders in rural-urban settings in Lagos State and to find the effect of
work-related musculoskeletal disorders on their functional performance. Our
study shows a high prevalence (97.7%) of WRMSDs among welders. This shows a
need for public awareness on the prevention of occurrence of musculoskeletal
disorders not only among welders but also for other similar occupational groups
in Nigeria. This result is in agreement with previous findings that reported
high prevalence of musculoskeletal disorders in industrial workers and across
the occupational groups [24-35]. However, the prevalence in this study is
higher than the previous one reported in Nigeria with upper limit of 63.9% [36]
(Tella et al 2009). It is also
higher than a similar study among the
same occupational group in United Kingdom with a prevalence rate of 80% [37].
The fact that low back problems occurred most
frequently among the participants could be attributed to their work postures,
as most of them either being in awkward posture or working with their back bent
continually at work. This result corroborates with previous findings that
reported the body area most frequently affected by WRMSDs is the lower back [6,
37]. In this study, it was observed that neck and shoulder disorders next to
low back pain may be due to the fact that large percentages of the participants
work with their lifted hand and extended neck. These prevalent disorders have
also been previously reported among welders in the United Kingdom [6, 37]. The
12-month prevalence value for presence of musculoskeletal disorder (68.9%) was
higher than the prevalence, (50%), that was reported by Leboeuf et. al [38]. in the Nordic population,
but lower than that (73%) in the United Kingdom [6, 37].
The
result indicates that musculoskeletal disorders have significant impact on job
performance including leisure activities and family role and it has caused some
werders to either reduce their work involvement or change their job. Effort
should be directed at preventive aspects to stem down musculoskeletal disorders
among the artisans to reduce dependency in activities of daily living. There
should be focus on early recognition and intervention when there is occurrence
of musculoskeletal disorders. This finding corroborates with that of Hoogendoorn et al
[35], who reported that low back pain, in addition to being particularly
prevalent was also more likely to result in reduced job performance (work
efficiency), leisure activity, longer duration of work incapacity, and greater
use of healthcare resources (e.g. medical consultations). The findings of this
study are consistent with literature that identifies lower back pain as a major
cause of losing work time and incapacity in the working population [23-34]. The
negative impact of WRMSDs on
leisure activity and family role agrees with previous studies by those who have
reported similar impacts [38].
Conclusion
From
the outcome of this study, it was concluded that there is high prevalence of
musculoskeletal disorder among welders in a rural-urban setting of Alimosho
Local Government Area of Lagos State. The most common WRMSDs among Nigeria
Welders in rural-urban areas are low back pain followed by neck and shoulder
pain. Musculoskeletal disorders have negative impact on job performance,
leisure activities and family roles among Nigerian welders working in a
rural-urban centre.
Acknowledgement
Authors thanks all people
who helped with this survey.
Conflict of interest: Non declared
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