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Abstract and Figures

Objective This study aimed to verify whether the saddle seat provides lower ergonomic risk than conventional seats in dentistry. Methods This review followed the PRISMA statement and a protocol was created and registered in PROSPERO (CRD42017074918). Six electronic databases were searched as primary study sources. The "grey literature" was included to prevent selection and publication biases. The risk of bias among the studies included was assessed with the Joanna Briggs Institute Critical Appraisal Tool for Systematic Reviews. Meta-analysis was performed to estimate the effect of seat type on the ergonomic risk score in dentistry. The heterogeneity among studies was assessed using I² statistics. Results The search resulted in 3147 records, from which two were considered eligible for this review. Both studies were conducted with a total of 150 second-year dental students who were starting their laboratory activities using phantom heads. Saddle seats were associated with a significantly lower ergonomic risk than conventional seats [right side (mean difference = -3.18; 95% CI = -4.96, -1.40; p < 0.001) and left side (mean difference = -3.12; 95% CI = -4.56, -1.68; p < 0.001)], indicating posture improvement. Conclusion The two eligible studies for this review provide moderate evidence that saddle seats provided lower ergonomic risk than conventional seats in the examined population of dental students.
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Assessment of the ergonomic risk from
saddle and conventional seats in dentistry: A
systematic review and meta-analysis
Giovana Renata GouvêaID
*, Walbert de Andrade Vieira
, Luiz Renato Paranhos
, I
de Macedo Bernardino
, Jaqueline Vilela Bulgareli
, Antonio Carlos Pereira
1Department of Community Dentistry, School of Dentistry of Piracicaba, University of Campinas, Piracicaba,
SP, Brazil, 2Department of Dentistry, University of Sergipe, Aracaju, SE, Brazil, 3Department of Preventive
and Community Dentistry, School of Dentistry, Federal University of Uberla
ˆndia, Uberla
ˆndia, MG, Brazil,
4Postgraduate Program in Dentistry, State University of Paraı
´ba, Campina Grande, PB, Brazil
These authors contributed equally to this work.
This study aimed to verify whether the saddle seat provides lower ergonomic risk than con-
ventional seats in dentistry.
This review followed the PRISMA statement and a protocol was created and registered in
PROSPERO (CRD42017074918). Six electronic databases were searched as primary
study sources. The "grey literature" was included to prevent selection and publication
biases. The risk of bias among the studies included was assessed with the Joanna Briggs
Institute Critical Appraisal Tool for Systematic Reviews. Meta-analysis was performed to
estimate the effect of seat type on the ergonomic risk score in dentistry. The heterogeneity
among studies was assessed using I
The search resulted in 3147 records, from which two were considered eligible for this review.
Both studies were conducted with a total of 150 second-year dental students who were start-
ing their laboratory activities using phantom heads. Saddle seats were associated with a sig-
nificantly lower ergonomic risk than conventional seats [right side (mean difference = -3.18;
95% CI = -4.96, -1.40; p <0.001) and left side (mean difference = -3.12; 95% CI = -4.56,
-1.68; p <0.001)], indicating posture improvement.
The two eligible studies for this review provide moderate evidence that saddle seats provided
lower ergonomic risk than conventional seats in the examined population of dental students.
PLOS ONE | December 17, 2018 1 / 14
Citation: Gouvêa GR, Vieira WdA, Paranhos LR,
Bernardino I
´dM, Bulgareli JV, Pereira AC (2018)
Assessment of the ergonomic risk from saddle and
conventional seats in dentistry: A systematic
review and meta-analysis. PLoS ONE 13(12):
Editor: Fabian Huettig, Eberhard-Karls-Universitat
Tubingen Medizinische Fakultat, GERMANY
Received: April 23, 2018
Accepted: November 26, 2018
Published: December 17, 2018
Copyright: ©2018 Gouvêa et al. This is an open
access article distributed under the terms of the
Creative Commons Attribution License, which
permits unrestricted use, distribution, and
reproduction in any medium, provided the original
author and source are credited.
Data Availability Statement: All relevant data are
within the paper and its Supporting Information
Funding: This work was supported by
Coordenac¸ão de Aperfeic¸oamento de Pessoal de
´vel Superior (CAPES) - process # 1595065, and
by Conselho Nacional de Desenvolvimento
´fico e Tecnolo
´gico (CNPq) - process #
Occupational health has been extensively investigated in dentistry [14], considering that den-
tists are professionals highly vulnerable to musculoskeletal diseases [5,6], especially in the cer-
vical and lumbar spines [7]. Working posture is the main risk factor for developing
musculoskeletal disorders [89].
The sitting posture is the body position that dentists use most frequently [10]. The dental
stool has an influence on such posture [1113], because it induces the use of certain postural
patterns to find a more comfortable and/or functional position [1113]. In addition, the curva-
ture of the spine, as well as the location and correct position of the head and pelvis are crucial
for the biomechanics of the sitting position [1416].
There is evidence that the 90˚ sitting posture (knee angle and hip angle) increases the pas-
sive tension of hamstring muscles, causing a posterior pelvic rotation and resulting in a
kyphotic sitting posture of the lumbar spine [1718]. However, ergonomic recommendations
[19], radiographic studies [1718], and analyses from physical therapists [20] and laypersons
[21,22] indicate that a sitting posture with a slight anterior tilt of the lumbar spine and a slight
lumbar lordosis of the lumbar spine reduces the incidence of low back pain most efficiently.
Aiming to reduce postural problems in dentistry, scientific studies have been performed to
elucidate the impact of different types of seats on the posture of students and trained profes-
sionals [16,23], as well as the importance of ergonomic seat interventions [14] in reducing
musculoskeletal symptoms [15]. However, the literature does not yet provide a consensus on
whether the saddle seat is a superior alternative to the conventional seat for maintaining opti-
mal posture.
Thus, the present study aimed to answer the following guiding question (based on the
PICO strategy): “Does the saddle seat (intervention) provide lower ergonomic risk (outcome)
to dentists and/or dental students (population) when compared with conventional seats (com-
parison)?” The authors have tested the hypothesis that using the saddle seat will promote lower
ergonomic risk than the conventional seat.
Protocol and registry
This systematic review was performed following the PRISMA (S1 PRISMA Checklist) state-
ment (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) [24] and the
Cochrane guidelines [25]. The systematic review protocol was registered in the PROSPERO
database under number CRD42017074918 (
Study design and eligibility criteria
The review included only randomized controlled trials that compared the working posture of den-
tal students and/or dentists in conventional seats without ergonomic changes and in ergonomic
saddle seats. There were no restrictions of year, language, or publication status (ahead of print).
The following were excluded: 1) Studies not related to the topic; 2) Reviews, letters to the
editor, personal opinions, book/book chapters, didactic material, reports, abstracts, and pat-
ents; 3) Qualitative or prevalence studies; and 4) Studies that used other types of seats or modi-
fied seats.
Sources of information and research
The primary sources of research were the electronic databases Embase, Latin American and
Caribbean Health Sciences (LILACS), PubMed (including MedLine), SciELO, Scopus, and
Assessment of the ergonomic risk in dentistry
PLOS ONE | December 17, 2018 2 / 14
Competing interests: The authors have declared
that no competing interests exist.
Web of Science. OpenThesis and OpenGrey were used to collect the “grey literature”, avoiding
selection and publication biases. A manual search was also performed through a systematic
analysis of the references of the eligible articles.
Two eligibility reviewers conducted the research independently (GG and WAV). The DeCS
(Descriptors in Health Sciences– and MeSH (Medical Subject Headings– resources were used for keyword selection. The Boolean
operators “AND” and “OR” were applied to enhance the search strategy through several com-
binations (S1 Table). The bibliographical research was developed and performed in August
2017. The search strategy included the following MeSH, DeCS, and Emtree terms: ‘Dentists’,
‘Posture’, ‘Human Engineering’, ‘Odontologia’ [Portuguese], ‘Postura’ [Portuguese] associated
with the entry terms: ‘Dental students’, ‘Student of dentistry’, ‘Undergraduate student of den-
tistry’, ‘Seated Position’, ‘Sitting Position’, ‘Saddle chair’, ‘Saddle seat’. The records obtained
were exported to the software EndNote Basic/Online, desktop version (Thomson Reuters,
New York, USA) and duplicates were removed.
Selection of studies
The studies were selected in three stages. In stage 1, two reviewers (GG and WAV) performed
a systematic analysis of the titles, independently. The articles whose titles met the objectives of
the study were selected for stage 2, when both reviewers (GG and WAV) also performed a sys-
tematic analysis of the abstracts. At this time, the studies not related to the topic, reviews, let-
ters to the editor, personal opinions, book/book chapters, didactic material, reports, abstracts,
patents, qualitative or observational studies, and studies that used other types of seats or modi-
fied ones were excluded. The articles whose titles met the study objectives, but had no abstract,
were fully reviewed.
In the third stage, the full texts of the preliminary eligible studies were obtained and evalu-
ated to verify whether they met the eligibility criteria. When both reviewers could not reach an
agreement, a third reviewer (LRP) was consulted to make a final decision. Rejected studies
were recorded separately along with the explicit reasons for exclusion.
Process of data collection and extraction
After the selection, two authors (MSS and WAV) analyzed the studies, which data were
extracted for the following information: article identification (author, year, study location),
sample characteristics (number of patients in each study, mean age, sex distribution, school
year), type of intervention (seat type, training time, evaluation start time), and methods for
obtaining the results (methods used for posture evaluation, image analysis, and calibration
time). Any disagreement was discussed and a third reviewer (LRP) was consulted when
Individual risk of bias of the studies
The risk of bias in the studies selected was assessed using the Joanna Briggs Institute Critical
Appraisal tools for use in JBI Systematic Reviews for Randomized Controlled Trials [26]. Two
authors (WAV and LRP) independently assessed each domain for the potential risk of bias.
The following questions were used for the assessment: 1) Was true randomization used for
assigning the participants to treatment groups? 2) Was the allocation to treatment groups con-
cealed? 3) Were treatment groups similar at baseline? 4) Were participants blind to treatment
assignment? 5) Were those delivering treatment blind to treatment assignment? 6) Were out-
come assessors blind to treatment assignment? 7) Were treatment groups treated identically
other than the intervention of interest? 8) Was follow-up complete, and if not, were differences
Assessment of the ergonomic risk in dentistry
PLOS ONE | December 17, 2018 3 / 14
between groups in terms of their follow-up adequately described and analyzed? 9) Were partic-
ipants analyzed in the groups to which they were randomized? 10) Were outcomes measured
in the same way for treatment groups? 11) Were outcomes measured in a reliable way? 12)
Was appropriate statistical analysis used? 13) Was the trial design appropriate, and were any
deviations from the standard RCT design (individual randomization, parallel groups)
accounted for in the conduct and analysis of the trial? The risk of bias was categorized as High
when the studies reached up to 49% of “yes” score, Moderate when they reached 50% to 69%
of “yes” score, and Low when the studies reached more than 70% of “yes” score. Studies cate-
gorized as either high risk of bias or low methodological quality were eliminated.
Outcome measures and data analysis
The meta-analysis for continuous outcome was performed to estimate the effect of seat type on
the ergonomic risk score in dentistry [25]. The mean difference was used for pooling effects.
Heterogeneity among studies was assessed using I
statistics and classified as follows: low (I
25%), moderate (I
= 50%), and high (I
>75%) [27]. The random-effects model was selected
to minimize the effect of heterogeneity among studies [28]. Publication bias was not assessed
because there was not a sufficient number of studies to group in a funnel plot. The software
Review Manager, version 5.3 (RevMan, Cochrane Collaboration) was used to perform all sta-
tistical analyses.
Confidence in cumulative evidence
The Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) tool
[28] assessed evidence quality and grading of recommendation strength. This assessment was
based on study design, methodological limitations, inconsistency, indirectness, imprecision,
and other considerations. Evidence quality was characterized as high, moderate, low, or very
low [29].
Selection of studies
The bibliographical research was developed and performed in August 2017. During the first
stage of study selections, 2993 records were found in six electronic databases. After removing
the repeated/duplicated records, 1918 articles proceeded to the analysis of titles and abstracts.
A total of 154 studies from the “grey literature” was found through the search strategy,
although only one was related to the objectives of the present review. After the analysis of titles
and abstracts, only three studies were eligible for full-text analysis. The references of the ini-
tially eligible studies were carefully assessed to verify potential articles that were absent from
the main search strategy. However, from the three studies included in this stage, one of them
was excluded for being a thesis from which an eligible article was produced. Therefore, two
articles proceeded to the analysis of results. Fig 1 reproduces the process of search, identifica-
tion, inclusion, and exclusion of articles.
Characteristics of the studies
Both eligible studies [1112] commented on the research ethical criteria and explained the use
of consent forms for research subjects. None of the studies presented either sample calculation
or study power. The analysis resulted in a total sample of 150 dental students and there were
no studies with professional dentists. The studies were performed in the United Kingdom [11]
in 2007 and in India [12] in 2014. One study compared the Salli Saddle Chair and a
Assessment of the ergonomic risk in dentistry
PLOS ONE | December 17, 2018 4 / 14
conventional chair with and without back rest and flat surface [12], and the other compared a
Bambach Saddle Seat and a conventional chair with back rest and flat surface [11]. Both studies
[1112] were performed with second-year dental students, who were starting their laboratory
activities using phantom heads.
The participants of the eligible studies [1112] received training as to correct posture and
use of each seat type. The evaluation was performed after 10 [11] or 12 [12] weeks so the stu-
dents would get used to the seats. Table 1 presents a summary of the main characteristics of
these studies.
Fig 1. Flowchart of the process of searching and selecting the literature, adapted from the PRISMA statement.
Assessment of the ergonomic risk in dentistry
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Risk of bias in the studies
Both studies included in this review [1112] presented low risk of bias in the Joanna Briggs
Institute Critical Appraisal tool [26]. Table 2 shows detailed information on the risk of bias of
the studies included.
Results of individual studies and meta-analysis
The studies selected used the RULA (Rapid Upper Limb Assessment) method [30], which ana-
lyzes the overload concentrated in the neck and upper limbs during work and assesses the
static muscle work and the forces exerted by the segments analyzed. The calibration time set
by the studies ranged from 10 [11] to 15 [12] minutes so that the students could focus on their
work and be evaluated afterwards. In both studies, the students prepared a mandibular tooth
in a mannequin.
In the study by Gandavadi et al. [11], photographs were taken of both left and right sides,
while in the study by Dable et al. [12], the analysis was performed from static images captured
from videos. The results showed lower scores for the ergonomic seats (Salli Saddle Chair and
Bambach Saddle Seat) than for conventional seats. In the study by Dable et al. [12], the authors
also used image magnification lenses to compare the groups, showing even lower scores with
such system.
Table 1. Summary of the main characteristics of the eligible studies.
Author, year,
and country
Seat type Sample (n) School
Location Procedure
Time of
et al., 2007,
Bambach Saddle
Seat (BSS)
Seat (CS)
Bambach Saddle
Seat: 30
Seat: 30
year Preclinical
preparation of
mandibular teeth
in a mannequin
10 weeks 2 weeks RULAPhotos 10 minutes
et al.,2014,
Salli Saddle
Chair (SSC)
chair with back
rest (CC1)
chair without
back rest (CC2)
Salli Saddle
Chair: 30
chair with back
rest: 30
chair without
back rest: 30
year Preclinical
preparation of the
first mandibular
premolar in a
12 weeks 3 days RULAVideos 15 minutes
RULA: Rapid Upper Limb Assessment.
Table 2. Risk of bias assessed by the Joanna Briggs Institute Critical Appraisal Tools for use in JBI Systematic Reviews for Randomized Controlled Trials” [26].
Authors Q.1 Q.2 Q.3 Q.4 Q.5 Q.6 Q.7 Q.8 Q.9 Q.10 Q.11 Q.12 Q.13 %yes/risk
Gandavadi et al., 2007 p p p pp p p p p p p 84.6%/Low
Dable et al., 2014 p p p pp p p p p p p 84.6%/Low
1) Was true randomization used for assigning the participants to treatment groups? 2) Was the allocation to treatment groups concealed? 3) Were treatment groups
similar at baseline? 4) Were participants blind to treatment assignment? 5) Were those delivering treatment blind to treatment assignment? 6) Were outcome assessors
blind to treatment assignment? 7) Were treatment groups treated identically other than the intervention of interest? 8) Was follow-up complete, and if not, were
differences between groups in terms of their follow-up adequately described and analyzed? 9) Were participants analyzed in the groups to which they were randomized?
10) Were outcomes measured in the same way for treatment groups? 11) Were outcomes measured in a reliable way? 12) Was appropriate statistical analysis used? 13)
Was the trial design appropriate, and were any deviations from the standard RCT design (individual randomization, parallel groups) accounted for in the conduct and
analysis of the trial? NA = Not Applicable; p= Yes; “–” = No.
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Fig 2 presents the forest plots. The mean differences in ergonomic risk score and their
respective 95% confidence intervals are represented by squares for the individual studies. The
S2 Table shows the risk score of individual studies. The diamonds at the bottom represent the
pooled mean ergonomic risk score with 95% confidence interval. The meta-analysis results
showed that saddle seats are associated with significantly lower ergonomic risk scores when
compared with conventional seats [right side (mean difference = -3.18; 95% CI = -4.96, -1.40;
p<0.001) and left side (mean difference = -3.12; 95% CI = -4.56, -1.68; p <0.001)], indicating
posture improvement. The overall mean difference in ergonomic risk score was -3.16 (95%
CI = -4.02, -2.30; p <0.001). Between-study heterogeneity was high (I
= 95%; p <0.001).
Confidence in cumulative evidence
Overall, the quality of evidence from the outcomes evaluated by the GRADE system [29] was
assessed as moderate (Table 3).
This study aimed to compare the ergonomic risk of saddle and conventional seats used in
work practices of dentists and/or dental students. Both eligible studies [1112] were performed
with a convenience sample (dental students). Studies with trained professionals may result in
Fig 2. Effect of seat type (saddle versus conventional) on ergonomic risk score in dentistry, assessed usingthe RULA scale.
Table 3. Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) summary of results table for the outcomes of the systematic review
and meta-analysis [29].
Quality Assessment Summary of Results Importance
Number of
Study Design Methodological
Inconsistency Indirectness Imprecision Publication
Number of participants General
Intervention Comparison
controlled trials
p p p p 60 60 +++
GRADE factors: = p, no serious limitations; X, serious limitation. General quality of evidence: +, very low; ++, low; +++, moderate; ++++, high.
Absence of blinding of outcome assessors and participants.
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PLOS ONE | December 17, 2018 7 / 14
bias due to the different situations of the clinical routine. Forming a control group for this type
of study, paired with the experimental group for age and time of profession, would represent
another challenge. These variables may reflect especially in existing musculoskeletal diseases
and in the resistance for changing usual postural practices [3132]. Thus, the results of the
present meta-analysis with studies performed with dental students significantly favor saddle
seats over conventional seats, which confirms the initial hypothesis.
In both eligible studies [1112], dental students were instructed to prepare a cavity in the man-
dibular teeth of a mannequin, at the preclinical laboratory. It is known that a procedure performed
in a dental mannequin does not reproduce the actual reality of a dentist’s routine. This is because a
real patient presents variables such as age (elderly people or children), anatomical structures (ton-
gue, cheek, and mouth opening limitation), special care (physical and/or mental disabilities),
altered psychological states (fear and/or anxiety), obesity, and pregnancy, which may change and
complicate the operational procedure. However, in the preclinical laboratory during procedures in
mannequins, students experience the first body postures, adapting their body to seat, static posture,
reduced field of vision, dental procedure, precision of fine movements, and especially to the fear
and insecurity of dealing with something new [33].
One of the methods for verifying ergonomic risks is the Rapid Upper Limb Assessment
(RULA) [30], which is the most cited in the literature and used in both eligible studies [1112]
of this review. In this method, the positions of individual body segments are observed and
assessed with increasing scores according to the growing deviation of the neutral posture [30].
Different studies [3034] have assessed the validity and reliability of the RULA, which is con-
sidered an adequate method to assess the body posture of dentists [35] and dental students
[36]. The observations of evaluators regarding the static image may be associated with the
uncertainty regarding camera angle [37].
Gandavadi et al. [11] observed the working postures of both right and left sides using digital
photographs. Dable et al. [12], in turn, used videos that were paused at every postural position and
at every body movement of both right and left sides. However, the assessment and final score of
both studies [1112] were based on a static image. The assessment of the body posture images of
the research participants started after 10 to 15 minutes in a familiar environment. Given the long
time for capturing the images, the participants were likely focused on the activity proposed and
kept the postural habits of their usual routine, which canceled the Hawthorne effect [38]—a phe-
nomenon in which participants change their behavior when they are aware of being watched.
In this study, the ergonomic risk was assessed in groups that used conventional and saddle
seats. The results indicated an intermediate to high score for ergonomic risk in the group
using the conventional seat, which is consistent with other studies [36,39]. Over the last
decade, research has been intensified, designing the effects of different seats on the clinical
practice of dentists and dental students [1113,4042]. Among such studies, three have investi-
gated the ergonomically modified stool [4042] and three have investigated the saddle seat
[1113]. All studies showed an improvement in the experimental group when compared to the
control group, especially for presenting a lumbar lordosis seated posture [1113].
There is a consensus among several studies [1721,4349] that the lumbar lordosed seated
posture is optimal for favoring a neutral lumbar posture, minimizing the painful symptomatol-
ogy of low back pain. It is also associated with high muscular activity and the increase in spinal
load due to the posterior pelvic tilt, which is then balanced by muscle contractions in the dorsal
spine, representing a dynamic posture [50]. This posture is obtained by positioning the lower
lumbar spine in a slight forward tilt and slight lumbar lordosis, while maintaining the relaxa-
tion of the muscles surrounding the thoracic spine [20].
In occupational science, a static body posture is defined as a posture held for more than
four seconds [5152]. Static work procedures prevent the blood flow required for tissue
Assessment of the ergonomic risk in dentistry
PLOS ONE | December 17, 2018 8 / 14
recovery. Other significant factors are the frequency of occurrence, the pauses during move-
ment, and the duration (time component) for maintaining a static body posture [53]. Conse-
quently, several dental tasks are performed in static postures with the prolonged flexion and/or
rotation of the trunk, presenting a potential risk for the musculoskeletal system [53].
The interdisciplinarity between bioengineering and health sciences improves clinical rele-
vance and research [19,5456]. Dynamic seats [5758] with a slight forward inclination
[54,5659], with or without a low backrest [57] to support the ischia [19,60], are the challenges
of novel seat designs. However, it is worth noting that adopting a good posture and using the
correct furniture are not enough to reduce the overload on the osteomyoarticular tissues of
dentists [6162]. Besides seat design, the human, occupational, and organizational factors also
play an important role in terms of load conditions in the human body [6365]. Psychosocial
factors are also major risk factors for persistent low back pain in workers, and they should be
considered along with the physical labor requirements, reducing the disability related to lum-
bar pain [66]. Such pain is also directly associated with depression and somatization [67]. Psy-
chosocial interventions may reduce the impact of low back pain in the workplace [68,69].
Four-handed dentistry, equipment organization in the workspace, correct positioning of
patients, illumination, and auxiliary components should be observed and controlled in the
dental clinical practice [6162]. The musculoskeletal stress of a dental professional is quantifi-
able, comparable, and especially rather variable, considering that musculoskeletal disorders
may be reduced by improving the ergonomic positioning of the patient and the practitioner
[70]. Positioning should maintain the natural curves of the lumbar spine (cervical lordosis,
thoracic kyphosis, lumbar lordosis, and sacral kyphosis), allowing a neutral sitting posture
[7,59] so that muscles and intervertebral discs may alternate between relaxation and loading.
Correct positioning is beneficial for nourishing muscles [71] and intervertebral discs [72] and
for potentially reducing ergonomic risks.
The present review is original, and it has contributed to develop the scientific knowledge
from two main points. Primarily, it is the first systematic literature review to investigate the
influence of seat type on ergonomic risk among dental students. Second, the low risk of bias
observed in the eligible studies allows drawing more consistent and reliable conclusions from
the data obtained, producing major implications for the academic dental clinical practice.
The present study is limited by the presence of only two clinical studies on the subject, with no
sample calculation or study power. In addition, the student population included only dental stu-
dents working on phantom heads and it was not sex-specific. In both studies included, the data
were collected only at the end of follow-up. It is worth noting that short-term investigations of the
sitting posture may not completely represent the biological time-dependent responses. Further
studies should be performed to determine whether the effectiveness of a saddle seat intervention is
maintained in the long-term, especially concerning the neutral lumbar posture. In addition, both
eligible articles used static images to represent the average posture of a person, which does not fit
the reality. Therefore, further studies need to employ state of the art posture measurement equip-
ment that automatically record the posture continuously. A combination of posture and Electro-
myography (EMG) measurement would provide additional insight.
The two eligible studies for this review provide moderate evidence that saddle seats provided
lower ergonomic risk than conventional seats in the examined population of dental students.
Follow-up studies are required to confirm this result by addressing the limitations of the
Assessment of the ergonomic risk in dentistry
PLOS ONE | December 17, 2018 9 / 14
studies. For example, follow-up studies should employ state of the art posture measurement
equipment and examine whether saddle seats also provide lower ergonomic risk in a popula-
tion of professional dentists treating real patients.
Supporting information
S1 PRISMA Checklist. PRISMA checklist.
S1 Table. Strategies for database search.
S2 Table. Main results of eligible articles.
Author Contributions
Conceptualization: Giovana Renata Gouvêa, Luiz Renato Paranhos, Jaqueline Vilela Bulgareli,
Antonio Carlos Pereira.
Formal analysis: Giovana Renata Gouvêa, I
´talo de Macedo Bernardino.
Investigation: Giovana Renata Gouvêa, Luiz Renato Paranhos.
Methodology: Giovana Renata Gouvêa, Walbert de Andrade Vieira, Luiz Renato Paranhos,
Jaqueline Vilela Bulgareli, Antonio Carlos Pereira.
Resources: Giovana Renata Gouvêa.
Supervision: Giovana Renata Gouvêa, Jaqueline Vilela Bulgareli, Antonio Carlos Pereira.
Writing – original draft: Giovana Renata Gouvêa, Walbert de Andrade Vieira, Luiz Renato
Paranhos, I
´talo de Macedo Bernardino, Jaqueline Vilela Bulgareli, Antonio Carlos Pereira.
Writing – review & editing: Giovana Renata Gouvêa, Walbert de Andrade Vieira, Luiz Renato
Paranhos, I
´talo de Macedo Bernardino, Jaqueline Vilela Bulgareli, Antonio Carlos Pereira.
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... Applying CASP assessment, the study by Roll et al. [17] was found to be the only systematic review included that was of high quality with a clear aim, methodology and applicable results. The study by Plessas and Delgardo [18] was considered to be of moderate to high quality, however the other three systematic reviews [3,19,20] were all low to moderate quality due to poor guiding questions or not being applicable to a clinically practicing dental professional. ...
... Regarding research on ergonomic equipment, systematic reviews identified examined the impact of ergonomically designed equipment on MSD experience. Two papers focused solely on the effect of ergonomically designed equipment on MSD preven-tion, such as stool design or the use of loupes in dental practice [18,19]. The systematic review by Plessas and Delgardo included four studies on the use of loupes in dental practice and concluded that using loupes decreased clinician discomfort [18]. ...
... (Continued) Chair design was examined in two systematic reviews. Gouvea et al. [19] and Plessas and Delgardo [18] both included dental chairs in their systematic reviews. Gouvea et al. found that saddle seats presented a significantly lower ergonomic risk compared to conventional seating. ...
Background: Musculoskeletal disorders (MSDs) are highly prevalent among dental professionals. Studies examining the prevention of dental work-related MSDs have been completed globally. Objective: To identify and evaluate the available evidence regarding MSD prevention in dental practice, and to identify knowledge gaps. Methods: An electronic search was conducted across multiple scientific databases. Identified articles were assessed according to inclusion/exclusion criteria. Systematic reviews, interventions and published expert opinion were included. Results: Five systematic reviews, 27 intervention studies and 21 expert opinion articles were included. There was overall consensus that use of ergonomic equipment is beneficial in MSD prevention. Knowledge gaps identified included: a lack of systematic reviews on the role of exercise and therapy in MSD prevention; a lack of high-quality intervention studies; a lack of research in general outside of ergonomic equipment use. Expert opinion articles have been published despite a lack of dental-specific research. Conclusions: Whilst more robust research is required, current evidence supports the use of optical enhancement, saddle chairs, and wide-diameter silicone-handled instruments in MSD prevention. Knowledge gaps were identified relating to the use of exercise, therapy, and education in the prevention of dental work-related MSDs. Further research is required, specifically high-quality intervention studies.
... Siendo los problemas de espalda los de mayor riesgo, según los resultados obtenidos; debería proponerse que los sillones de trabajo para el profesional y/o estudiante de odontología disminuyan el riesgo ergonómico; sin embargo, en una meta análisis se encontró evidencia moderada de que los sillones proporcionen un menor riesgo ergonómico que los asientos convencionales en una población examinada de estudiantes de odontología 14 . ...
... Being back problems the highest risk, according to the results obtained; it should be proposed that work chairs for dental professionals and / or students reduce ergonomic risk; however, in a meta-analysis moderate evidence was found that the chairs provide a lower ergonomic risk than conventional seats in an examined population of dental students 14 . ...
... Un limitante del estudio es que se ha utilizado solo un método de evaluación, los resultados de revisiones sistemáticas sugirieron usar más de una técnica para la evaluación postural 14 ; aunque, falta establecer la aplicabilidad de las técnicas en la odontología en particular. Existen técnicas que aún no se comparan para verificar el acuerdo o la correlación, y que sirven como un vacío de investigación. ...
Los odontólogos por su trabajo pueden adoptar posturas anormales, generando un riesgo de desarrollar trastornos musculoesqueléticos, si se ignora, el daño fisiológico acumulativo puede provocar una lesión que afecte el ejercicio profesional. Objetivo: El estudio evaluó el riesgo ergonómico de desarrollar trastornos musculoesqueléticos en estudiantes de odontología utilizando el Sistema de Análisis de Trabajo Ovako (OWAS por sus siglas en inglés). Material y Métodos: Estudio observacional en estudiantes matriculados (n=90) en el último semestre de pregrado de la Facultad de Odontología de la Universidad Central. Para determinar el riesgo de desarrollar problemas musculoesqueléticos se usaron imágenes de videos y fotografías de estudiantes mientras realizaban diversos procedimientos clínicos que se evaluaron usando el método OWAS. Las observaciones se realizaron en un periodo de 20 a 40 minutos con un intervalo de 30 a 60 segundos de descanso. Se atribuyó una puntuación de riesgo después de cada procedimiento realizado por el estudiante. La prevalencia del riesgo de trastornos musculoesqueléticos se estimó por posición. Resultados: El mayor riesgo se presentó en la espalda, el 68% de los alumnos asumió alguna posición que a largo o corto plazo necesitaría consideración por el riesgo de desarrollo de lesiones musculoesqueléticas. El 60% presentó una posición desfavorable para los brazos. Respecto a la carga sobre los pies, más del 80% trabajó sentado, por lo que el riesgo fue menor en esta posición; la fuerza no fue observada como factor de riesgo. Conclusiones: Se observó una mayor prevalencia de riesgo medio (2 y 3) de desarrollar trastornos musculoesqueléticos principalmente en la espalda en estudiantes de último semestre de la carrera de Odontología.
... 14 For this review, when positive answers were [?]49%, the risk of bias was considered high risk; between 50% and 69%, the risk of bias was considered moderate; and when positive answers were above 70%, the risk of bias was low, according to other studies using the same tool. 15 ...
Aims: to systematically review the prevalence of DCD in individuals born preterm; explore this prevalence according to gestational age and different assessments cut-offs; and compare to full-term peers. Methods: The eligibility criteria was observational and experimental studies reporting the prevalence of DCD in preterm individuals. A systematic search was performed in databases from inception until March 2022. The selection was performed by two independent reviewers. Study quality assessment was performed using the checklists from Joanna Briggs Institute (JBI). Data analysis were performed on Excel and Review Manager Software 5.4. Results: Among the 1774 studies identified, 32 matched the eligibility criteria. The pooled estimates of DCD rate in preterm was 21% (95% CI 17.8–24.3). The estimate rates were higher as gestational age decreased, and preterm children are two times more likely to have DCD than their full-term peers RR 2.2 (95% IC 1.77–2.79). Interpretation: The limitation was high heterogeneity between studies: the assessment tools and cut-off points, as well as the age at assessment, were diverse. This study provided evidence that preterm children are at higher risk for DCD than full-term children, and the risks increased as gestational age decreased.
... According to Gouvêa et al. [22] the saddle stools are more favorable to dental students when compared to conventional ones and may be beneficial for students´compliance to ergonomic posture requirements in the clinic. This stool offers a comfortable posture as it bends the pelvis into an almost neutral position, simulating a standing position with well supported legs and thighs. ...
Full-text available
Objective This study aimed to evaluate the perceptions of third-year dental students regarding the application of ergonomic principles in the transition between preclinical and clinical training in Restorative Dentistry. Methods We conducted a qualitative observational cross-sectional study. The sample consisted of forty-six third-year dental students at São Paulo State University (Unesp), School of Dentistry, Araraquara. Data was collected using an individual interview recorded on a digital voice recorder. A script containing questions related to the process of adaptation of students to clinical care with a view to ergonomic work posture was used. Data analysis was based on the quali-quantitative technique of Discourse of the Collective Subject (DCS), using Qualiquantisoft®. Results Most students (97.80%) perceived the need for an adaptation period in the transition from the preclinic to the clinic regarding ergonomic posture requirements; a part of them (45.65%) claimed that they still could not adapt, primarily due to the difference between the laboratory and clinic in the workstation (50.00%). Some students suggested longer preclinical training in a clinical environment to facilitate this transition (21.74%). The dental stool (32.60%) and the dental chair (21.74%) were the external factors that contributed most to making this transition difficult. The difficulty of the restorative dentistry procedure (10.87%) also interfered with posture. Additionally, the most challenging ergonomic posture requirements in the transition period were maintaining 30 to 40 cm between the patient’s mouth and operator’s eyes (45.65%), positioning the patient in the dental chair correctly (15.22%), and working with the elbows close to the body (15.22%). Conclusion Most students perceived the need for an adaptation period in the preclinical transition to the clinic, attributing difficulties to adopt the ergonomic posture requirements, to use the workstation and to perform the procedures on real patients.
... To solve this problem, ergonomics is the best solution for scientific research in manmachine interaction at the workplace since this field involves fitting machine to workers comfortability to improve their working performance, reduce fatigue, and stress [15]. The ergonomic application is very significant in areas involving prolonged and static riding activities that directly affect the riders' healthy spinal posture and reduce muscle fatigue. ...
Full-text available
Traffic police riders are exposed to prolonged static postures causing significant angular deviation of the musculoskeletal, including the lumbar angle (L1-L5). This postural alteration contributes to awkward posture, musculoskeletal disorders and spinal injury, especially in the lower back area, as it is one of the most severe modern diseases nowadays. Thus, the study aimed to evaluate the effect of lumbar support with a built-in massager system on spinal angle profiles among traffic police riders. A randomised controlled trial (pre-testpost-test control design) was used to assess spinal angle pattern while riding the high-powered motorcycle for 20 minutes. Twenty-four traffic police riders were randomly selected to participate and 12 riders were assigned to the control group and 12 riders to the experimental group. The pre-test and post-test were conducted at a one-week interval. Each participant was required to wear a TruPosture Smart Shirt (to monitor spinal posture). The TruPosture Apps recorded the spinal angle pattern. The data indicated that the police riders using motorcycle seat with lumbar support and built-in massager system showed a huge improvement in maintaining posture which only involves slight spinal angle deviation changes from the spinal reference angle throughout the 20 minutes ride. The data collected then were analysed using the Mann-Whitney test and Wilcoxon signed-ranked test to verify a statistically significant difference between and within the control and experimental groups. There were significant differences in all sensors between the control group and experimental groups (p
... Common ergonomic designs that promote these beneficial posturesas well as alternation and movement -have used higher chairs with forward slopes, saddle chairs, and adjustable height desks (Mandal, 1991;Roossien et al., 2017;Kuster et al., 2018;Noguchi et al., 2019;Chambers et al., 2019;Vaucher et al., 2015;Johnston et al., 2019). Demonstrated across different populations -from dentists (Gouvêa et al., 2018) to school children (Castellucci et al., 2016a,b) -hybrid sitting interventions incorporate furniture and equipment that allow users to modify their sitting posture according to their preference, work-related use, and comfort. Moreover, they have been shown to be more effective than any single static posture (Noguchi et al., 2019). ...
Anthropometry is critical for product and workplace design. Highly prevalent, office work is associated with sedentarism and physical discomfort due to prolonged sitting. Dynamic seating (alternating across sitting, perching, and standing) has been suggested as an alternative to overcome those problems. The current study tested a large sample of anthropometric data for mismatch levels against national and international office furniture standards using dynamic seating as a framework with traditional and perching mismatch equations, applied to three recommended dynamic seating components. Dimensions present in the standards used did not match the majority of the sample. For sitting, seat width and depth individually presented the lowest levels of match, as well as under cumulative fit of all office furniture dimensions. However, these were alleviated when incorporating adjustability. Perching was shown to be generally impeded given commercially-available chair height options. Limitations in state-of-the-art perching equations are discussed, and two new models are proposed as design alternatives. Further research should focus on testing the criteria presented in this research through discomfort and objective measures.
... It should also provide appropriate height, optimum arm, and elbow support. Saddle stool is ideal for working as it maintains the lumbar curve of the lower back [4,[21][22][23] 12. Patient chair should have a flat surface. It should be stable and should come with proper drop-down armrests, headrest, neck support, wrist, and forearm support [4] 13. Four-handed dentistry is one of the recent trends in the dental practice. ...
Full-text available
The objective is to develop a system to automatically select the corresponding assessment scales and calculate the score of the risk based on the joint angle information obtained from the imaged process (OpenPose) via image-based motion capture technology. Current occupational assessments, for example, REBA, RULA, and OWAS were used to evaluate the risk of musculoskeletal disorders. However, the assessment result would not be reported immediately. Introducing real-time occupational assessments in different working environments will be helpful for occupational injury prevention. In this study, the decision tree was developed to select the most appropriate assessment method according to the joint angles derived by OpenPose image process. Fifteen operation videos were tested and these videos can be classified into six types including maintenance, handling, assembly, cleaning, office work, and driving. The selected ergonomic assessment method by our developed decision tree in each condition are consistent with the recommendation of the Labour Research Institute. Moreover, the high-risk posture could be identified immediately and provide to the inspector for further evaluation on this posture rather than the whole operation period. This approach provides a quick inspection of the operation movements to prevent musculoskeletal injuries and enhances the application of the scale assessment method in different industrial environments.
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[Purpose] The present research was undertaken to investigate the awareness of ergonomics and prevalence of musculoskeletal disorders among dental professionals and students in Riyadh, Saudi Arabia and to find a mean to decrease the prevalence of musculoskeletal disorders in the future. [Subjects and Methods] A self-administered survey was prepared and disseminated to dental professionals and students in Riyadh, Saudi Arabia. The questionnaire was focused on the awareness of ergonomics and musculoskeletal disorders. Five hundred and sixty-one participants were included in this survey. [Results] Within the present study, significant differences were noticed among specialists, general practitioners and undergraduate students. Work load (risk factors) had great influence on musculoskeletal disorders in all dental practitioners, and lower back pain was the most common reported disorder among all practitioners. [Conclusion] Most of the respondent dentists seem to work in conditions that aggravate disorders of the musculoskeletal system, the increased prophylactic remedies were directly associated with the increase of the musculoskeletal disorders symptoms. All dentists regardless of their dental specialties, are recommended to apply principles of ergonomics in their daily practice. Moreover, dental ergonomics should be taught to undergraduate students and strictly implemented in the clinics to provide comfortable working environment for all dental professionals.
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Introduction Dental practitioners are exposed to different occupational hazards during the course of their professional activity, such as physical, chemical, biological, ergonomic factors. The ergonomic hazards, caused by strained posture and prolonged repetitive movements, can induce musculoskeletal disorders. It occurs in 54–93% of dental professionals and involve the spine, shoulder and hand-wrist tract. Through a systematic review of international literature, we analyzed specific ergonomic risk factors and preventive measures of musculoskeletal disorders in professional dental activity. Methods This systematic review is coherent with the PRISMA statement. The scientific research on the major online databases was based on the following keywords: dentist, prevention, ergonomic, dentistry, musculoskeletal, neck pain, posture, ergonomics, work and occupational. The studies included in this review focus on disorders related to ergonomics and on the most effective preventive measures to be adopted. No restrictions were applied for language or publication type. We excluded reports not related to ergonomic prevention in dentistry, reports of minor academic significance, editorial articles, individual contributions, and studies published in scientific conferences. Results Online research indicated 4188 references: PubMed (2919), Scopus (1257) e Cochrane Library (12). We excluded 3012 of these, because they were unrelated to ergonomics theme and 187 due to duplication. From the remaining 989 studies, 960 papers did not meet inclusion criteria and they were excluded. Therefore, we analyzed 29 articles, including 16 narrative reviews and 13 original article. The main risk factor for the development of musculoskeletal disorders found in our analysis is static posture adopted during work, highlighted in 87.5% of reviews and 84% of original articles. With regard to preventive measures, 75% of the reviews highlighted the importance of stretching after each working session and at the end of the working day, while 61.5% of the original articles emphasized the use of modern and ergonomic instruments. Discussion This review showed that static postures are strongly responsible in the etiology of musculoskeletal disorders. The awkward postures more frequently identified among dental professionals are: extreme forward-head and neck flexion; trunk inclination and rotation towards one side; lifting one or both shoulders; increased curvature of the thoracic vertebral column; incorrect positioning of the lower limbs with thigh-leg angle of less than 90°. It is really important to use of a modern workstation with appropriate ergonomic supports. Among the preventive ergonomic measures, literature has widely recognized the role of physical activity and of a neutral and balanced posture. The present review has some limits: a large part of the selected studies did not have a high methodological quality score and an inadequate statistical analysis.
Conference Paper
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Objective To identify the main determinants of occupational diseases at both the individual and the population level. Methods This study used data from the Dutch National Working Conditions Survey (NWCS 2014; occupational disease confirmed by a doctor, self-reported, employees). Multivariate regression analyses were performed to assess the independent association at the individual level (OR) between each determinant and the presence of at least one occupational disease. Additionally, the Population Attributable Risk (PAR) was calculated for each determinant in order to assess the risk at the population level as well. Results The top three determinants that may be influenced and also contributed most to musculoskeletal occupational diseases, were the same at the individual and the population level: ‘Repetitive movements‘ (PAR=40.0%; OR=2.25), ‘Working in uncomfortable positions/bad posture‘ (PAR=17.7%; OR=1.62), and ‘High job demands‘ (PAR=17.6%; OR=1.57). Determinants that contributed most to psychological occupational diseases were also the same on the individual and population level: ‘Low engagement‘ (PAR=33.6%; OR=2.27), ‘Conflict with supervisor‘ (PAR=16.7%; OR=1.51), and ‘High emotional demands‘ (PAR=14.4%; OR=2.85). Conclusion These determinants may be influenced through education, measures and/or policies at the workplace or on higher levels, in order to decrease the prevalence of occupational diseases in the working population.
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Background: Professional practice and dental training have many risk factors, and the dental team should be able to recognize these factors to protect themselves. The prevalence of conditions related to the musculoskeletal system, stress, percutaneous injuries, ears, and eyes are of concern. The dental team should also not forget hepatitis B, hepatitis C, and HIV as risks in practice. Dental practitioners should protect themselves by self-recognizing risk factors and by maintaining proper working conditions. Methods: The study targeted all empirical research, case studies, and systematic literature reviews written in English. All articles selected were subjected to a data analysis process. Data were captured on an Excel spreadsheet and reported in a comprehensive table. Results: The literature addressing occupational health among dental practitioners included mainly cross-sectional studies and review papers (2001-2016). Forty-nine studies were included in the review. Musculoskeletal disorders remain the most researched occupational health-related problems in dentistry. Eye protection compliance was low among practitioners. Percutaneous injuries especially among young dentists and students were still a concern. Conclusion: Occupational health-related problems are still prevalent in current dentistry practice, despite changes in equipment and surgery design. The reported prevalence of occupational related-health problems and other findings of investigative studies highlight the need for continuous professional education and a need to improve clinical practice aspects of dentistry curricula.
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Introduction Musculoskeletal disorders (MSD) have become significant problems for all health care workers especially dentists. This systematic review provides prevalence of MSD in dentists of Iran. Material and Methods In this study all published literatures about MSD in Iranian dentists were selected without any time limits or other restrictions. However, it was found that the studies about MSD among Iranian dentist are very low. Results The results of literatures investigations show that the prevalence was between 0.5% and 70%. The prevalence of pain in different regions includes; neck pain (0.7- 0.15), back pain (0.08 - 0.55), wrist pain (0.005-0.48), shoulder pain (0.08-0.5), knee pain (0.03- 0.25) and elbow pain (0.01- 0.2). The gender has no influence on the prevalence. Compare the results with other similar studies shows that the prevalence of MSD is an important issue in other area too. Conclusion Results show that the prevalence of musculoskeletal problems is high in Iran. Therefore it is necessary conduct reliable and comprehensive epidemiological studies in this field to determine the causes of the problem more consciously; and propose appropriate solutions.
Objectives Musculoskeletal disorders affect a high percentage of dentists, dental hygienists and therapists. Static and awkward working postures are considered as major risk factors. Proper seat selection and use of magnification loupes are promoted for their ergonomic benefits. The aim of this review was to evaluate the existing empirical evidence on the effect of the above interventions on (i) correction of poor posture and (ii) reduction in musculoskeletal pain. Methods The review was conducted according to the PRISMA guidelines. The review protocol was registered with PROSPERO (CRD42017058580). The Medline via Ovid, CINHAL via EBSCO, Web of Science, OpenGrey and EThOS electronic databases were searched. Prospective experimental studies were considered for inclusion. The Effective Public Health Practice Project Quality Assessment Tool (EPHPP) was used to assess the methodological quality of the included studies. Results Eight studies were included in the review. Four investigated the effect of loupes on posture and musculoskeletal pain, 4 the effect of the saddle seats on posture and one of the latter explored the combined effect of magnification and use of saddle seats on posture. Conclusions Based on a limited number of studies, the use of ergonomic saddle seats and dental loupes leads to improved working postures. The use of loupes appears to relieve shoulder, arm and hand pain. However, their effect on neck pain is scarce. None of the studies reported on the effect of the saddle seats on musculoskeletal pain. Future well-powered prospective longitudinal studies are deemed necessary to confirm the conclusions of this review. available:
The aims of this study were to adapt the Job Factors Questionnaire to the field of dentistry, evaluate its psychometric properties, evaluate dental students' perceptions of work/study risk factors for musculoskeletal disorders, and determine the influence of gender and academic level on those perceptions. All 580 students enrolled in two Brazilian dental schools in 2015 were invited to participate in the study. A three-factor structure (Repetitiveness, Work Posture, and External Factors) was tested through confirmatory factor analysis. Convergent validity was estimated using the average variance extracted (AVE), discriminant validity was based on the correlational analysis of the factors, and reliability was assessed. A causal model was created using structural equation modeling to evaluate the influence of gender and academic level on students' perceptions. A total of 480 students completed the questionnaire for an 83% response rate. The responding students' average age was 21.6 years (SD=2.98), and 74.8% were women. Higher scores were observed on the Work Posture factor items. The refined model presented proper fit to the studied sample. Convergent validity was compromised only for External Factors (AVE=0.47), and discriminant validity was compromised for Work Posture and External Factors (r2=0.69). Reliability was adequate. Academic level did not have a significant impact on the factors, but the women students exhibited greater perception. Overall, the adaptation resulted in a useful instrument for assessing perceptions of risk factors for musculoskeletal disorders. Gender was found to significantly influence all three factors, with women showing greater perception of the risk factors.
Conference Paper
Objective To determine whether overweight and obesity and age are associated with a higher risk of accidents at work and occupational disease. Background Data During recent years, professional contingencies have been increasing at work, a change that coincides with a higher prevalence of obesity and older work population. Methods This cross-sectional study was carried out among 1489 workers in healthcare industry. This study identified the prevalence of obesity and overweight in a hospital and its associations with occupational diseases and accidents at work over a 4 years‘ period. With and without absences from work and the length of the absences were recorded. Body mass index (BMI) and demographic details were recorded. Results At baseline, 48,3% had normal-weight (BMI [body mass index]: 18.5–24.99 kg/m 2), 34,3% were overweight (BMI: 25–29.99 kg/m 2), 14,8% were obese (BMI ≥30 kg/m 2), and 2,6% were underweight (BMI <18.5 kg/m 2). During the 4 years‘ period, with a mean of 46 years, 263 participants were diagnosed with a professional contingency (accident at work or occupational disease). Compared with normal-weight individuals, there was no statistically significant difference having an occupational contingency between overweight and obese workers (p-value 0,161). Although, we found that the age is a risk factor of having an accident at work. Conclusion Obese and overweight persons are not at a higher risk of developing an occupational contingency. Furthermore, our results indicate that the age might be a novel explanation for the increased number of workers with accidents at work.
Introduction: The association between depression, somatization and low back pain has been minimally investigated in a Canadian emerging adult population. Methods: 1013 first year Canadian university students completed the Modified Zung Depression Index, the Modified Somatic Perception Questionnaire, and a survey about low back pain frequency and intensity. Multinomial logistic regression was used to measure associations between low back pain and depression and somatization, both independently and co-occurring. Results: Over 50% of subjects reported low back pain across grades, and both depression and somatization were significantly positively associated with low back pain. Several positive associations between the cooccurrence of somatization and depression with various grades of low back pain were observed. Discussion: These results suggest that low back pain, depression and somatization are relatively common at the onset of adulthood, and should be considered an important focus of public health.