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Tablet arm chair and its subsystems: (A) seat, (B) backrest, (C) tablet arm, (D) tablet arm extension, (E) material holder
Source publication
The purpose of this study was to develop and validate an evaluation instrument for tablet arm chairs based on ergonomic requirements, focused on user perceptions and using Item Response Theory (IRT). This exploratory study involved 1,633 participants (university students and professors) in four steps: a pilot study (n=26), semantic validation (n=43...
Contexts in source publication
Context 1
... items were placed in the instrument according to the parts that compose the tablet arm chair, and considered the subsystems - seat, backrest, tablet arm, tablet arm exten- sion and material holder ( Figure 1) -and general items were included about school furniture. To help the respondents under- stand the items, drawings that clarify the er- gonomic requirements to which each item re- fers were placed in the instrument used to validate the construct. ...
Context 2
... standard error curve shows that the instrument will generate more accurate estimates (low standard errors < 0.19) of the degree of ergonomic suitability of the tablet arm chair in regions with high information. One can see in Figure 3 that the instrument is able to generate good estimates in the range of 2 standard deviations above and below the mean (zero), which is a fairly wide range in the scale (0, 1). Accordingly, the developed instrument is suitable for evaluating tablet arm chairs and users with different character- istics, that is, tablet arm chairs with low, av- erage or high ergonomic suitability. ...
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Citations
... Certain instruments, such as questionnaires and diagrams, are used to indirectly evaluate symptoms of discomfort [12]. In addition, metrics are used to verify the level of discomfort in different contexts, such as aircraft seats [10], school desks [13], and musculoskeletal discomfort [14]. ...
... Additionally, they did not verify that these differences were absent in the evaluated samples [33]. Therefore, studies on ergonomics have overlooked the differences [10,[12][13][14]34]. ...
Musculoskeletal symptoms are a major occupational health problem in workers, and these can affect all professional occupations. Previous studies have proposed metrics capable of evaluating the musculoskeletal discomfort experienced by workers. However, no study has developed a metric that considers professional groups. Thus, this study aimed to develop a scale for musculoskeletal discomfort in the lower limbs to compare self-reported symptoms among education, health, and industry professionals. The sample included 159 teachers, 167 health professionals, and 401 industrial operators who relayed their symptoms using a diagram of the hips, thighs, knees, lower legs, and feet. Factor and multigroup item response theory analyses were used to construct a musculoskeletal discomfort scale consisting of seven levels and to assess and compare the identified symptoms. The results showed that the progressive evolution of discomfort differed for each profession, demonstrating that each context and work environment affects workers differently, which may explain the different patterns of symptom responses among professional groups.
... In ergonomics, such discomfort has been related to the presence of pain (Zhang, Helander, and Drury 1996) accompanying musculoskeletal disorders . Therefore, metrics have been devised, for example, to verify the discomfort of objects such as school desks (Tirloni et al. 2016) and aircraft seats (Menegon et al. 2019). These metrics may also be used to quantify the level of musculoskeletal discomfort in workers ). ...
Owing to biological and social factors, illness-related musculoskeletal symptoms tend to vary between men and women. However, in the past, conceptualised discomfort metrics were applied uniformly to both genders. This study aimed to develop a scale to measure musculoskeletal discomfort that compares the symptoms between men and women. The scale aimed to determine the gender-based response patterns related to symptoms. A total of 707 men and 1302 women reported their symptoms on a body map. Factor analysis and item response theory were used to differentiate the identified symptoms in the construction of a musculoskeletal discomfort scale. Differences in work exposure appeared to explain the symptom patterns between men and women. The scale had eight levels, and it was found that at the same level of discomfort, men and women reported symptoms in different body regions.
Practitioner summary: On this discomfort scale, the response patterns of men and women were categorised into eight levels. Symptoms differed by gender at the same musculoskeletal discomfort level. This is in contrast to previous studies in which scales were devised without considering differences between the genders.
Abbreviations: WMSDs: work-related musculoskeletal disorders; BMI: body mass index; FA: factor analysis; IRT: item response theory; KMO: Kaiser–Meyer–Olkin; BST: Bartlett's test of sphericity; F: factor loading; h2: communality; α: Cronbach’s alpha; ωt: McDonald’s omega; ai: parameters of discrimination of the items; bik: parameters of difficulty of response categories; θj: latent trait; RMSEA: root mean square error of approximation; CFI: comparative fit index; TLI: Tucker–Lewis index; odu: musculoskeletal discomfort units; RA: rarely; OF: often; AL: always.
... The validity and reliability of IRT studies are observed through the results of the factor analysis, the analysis of item parameters and the creation of the measurement scale, ensuring psychometric quality to the instrument (Menegon et al. 2017). Thus, through factor analysis, the construct's validity was verified (Suter 2006) and through the IRT the quality of the items was analysed in terms of discrimination (Tirloni et al. 2016). ...
This study aims to build a scale for musculoskeletal discomfort based on the self-reported musculoskeletal pain by individuals. For this, methods such as factorial analysis and item response theory were used. A sample of 1821 workers of a footwear industry participated in this study. The scale consists of four levels ranging from mild to maximum discomfort. In mild discomfort (level 60), pain symptoms are rare or frequent in regions such as cervical and trapezoidal area, low back, shoulders, wrists, ankles and feet. At level 70, rare or frequent symptoms affect regions of the upper and lower limbs. At level 80, frequent symptoms become common in the trunk and in most of the upper and lower limbs. At level 90, the symptoms become daily in elbows, thighs and knees. The scale showed signs of validity and proved useful for studies in ergonomics.
Practitioner Summary: Methods such as factor analysis and item response theory were used to build a four-level musculoskeletal discomfort scale that can be useful to complement the screening process for workers with musculoskeletal pain. The scale shows signs of accuracy, in addition to validity and reliability.
Abbreviations: WMSD: work-related musculoskeletal disorders; CTT: classic test theory; IRT: item response theory; KMO: Kaiser–Meyer–Olkin; PR: pain rarely; PO: pain often; PE: pain everyday; DIF: differential item functioning
... It is a methodological process related to the precision of the instrument to measure what it purports to measure [22]. Content and semantic validity are steps of the validation process, which can be accomplished by a panel of judges or experts experienced in the subject matter [23]. Content validity is the ability of each item of the instrument to sufficiently represent the content domain while observing grammar, the use of appropriate and correct words and the application of the correct and proper order of words in items [24]. ...
This study aimed to develop and validate a checklist instrument as a first step for the risk assessment of the hygienic-sanitary practices and conditions of food trucks. We invited sixteen experienced experts in the food safety field to take part in the process. The checklist was designed based on the Codex Alimentarius, Brazilian resolutions Collegiate Board Resolution 216, Brazilian Collegiate Board Resolution 275, Brazilian Federal District Law no. 5.627 and Brazilian Federal District Normative Instruction 11. The preliminary version of the checklist—composed of 29 items (nine sections)—was evaluated by 13 experts. They evaluated the items regarding their importance (content validation) and clarity (semantic evaluation) by the Delphi technique. The criteria for the approval of the content validation (Likert scale from 1 to 5) and semantic evaluation (Likert scale from 0 to 5) processes were as follows: a minimum of 75% agreement among the experts (W-values ≥ 0.75) and a mean grade ≥ 4. We performed the complete validation process in three rounds. The final version of the assessment instrument comprised 39 items, following suggestions from experts to add or subdivide some questions. The checklist can be used to conduct inspections of food trucks by health surveillance auditors, of food truck vendors’ decision-making processes and also as a diagnostic tool. The application of this checklist will allow the effective risk assessment of the hygienic-sanitary practices and conditions in food trucks and potentially ensure consumers’ access to safe street food.
... Por outra parte, a Antropometria também forma parte da Ergonomia, termo originário da Grécia (ergo = trabalho e nemo = ciência), que estuda as relações espaciais e tridimensionais existentes entre o ser humano e o espaço que ele ocupa, uma aplicação utilizada pela Engenharia. Na Ergonomia, as dimensões corporais têm um papel importante na confecção de materiais escolares, tais como mesas e cadeiras (TIRLONI et al., 2016), adequar estações de trabalho para melhorar a qualidade de vida dos trabalhadores desde escritórios até frigoríficos (REIS et al., 2012;TIRLONI, 2008). ...
Body composition assessment has been widely used in the area of Clinical Nutrition, Sports and Physical Training in clinical and scientific environments. Measurement of body composition parameters such as adipose tissue mass, fat free mass, body cell mass, total body water, and extracellular water can provide important information on the effectiveness of clinical, physical activity, and nutritional interventions. Despite the availability of gold-standard methods for assessing body composition, such as dual-energy radiologic absorptiometry, which can provide a detailed and reasonably accurate distribution of adipose tissue mass, fat-free mass, and bone mineral content in the body, the method Bioelectrical Impedance (BIA) appears as a valid, easy-to-use, epidemiological and relatively low cost alternative to assess lean mass, total body water, extracellular water and fat mass.
... IRT is a tool that is broadly adopted in studies in the field of education and is now used in other fields including environmental management (Trierweiller et al., 2013), entrepreneurial potential (Alves & Bornia, 2011), total quality management (Alexandre, Andrade, Vasconcelos, Araujo, & Batista, 2002), ergonomics (Tirloni et al., 2016), and others. Kean (2014) defines IRT as a set of mathematical models for measuring latent traits (Ө), that is, characteristics that cannot be measured directly, such as reporting on sustainability of the supply chain. ...
... Note that in Figure 5, the scale developed is more suitable to measuring the level of reporting on supply chain sustainability by the companies that are found in the interval of −0.5 to 2.5, because this is the region with the most amount of information and the lowest mean standard of error, below 0.18. According to Tirloni et al. (2016), the more information there is (continuous line) and ...
The purpose of this article is to measure the level of reporting about supply chain sustainability using item response theory (IRT). IRT allows inserting items and their respondents into a single scale and creating interpretable scales. An instrument composed of 24 items was prepared and applied to 345 sustainability reports from companies in 21 sectors of the Brazilian economy. It used Samejima's gradual response model to construct a scale to measure the level of reporting on supply chain sustainability. As a result, five interpretable levels were identified in the scale constructed (Minimum, Low, Medium, Medium High and High). The reporting about the supply chain in most of the sustainability reports analyzed (48.41%) is concentrated at the scale's lowest or minimum level: 24.93% are at the second or low level, 2.61% are at the medium level, and only 0.29% of the reports are at the high level of the scale.
... Again, providing highly adjustable furniture along with adequate training of the users is a key requirement for ergonomic interventions of seated workers [4,8]. Various international standards such as the ISO 5970:1979, have established recommended chair and table sizes with respect to the height of the user [9] and chairs with high backrests can reduce the likelihood of low back pains [3,6]. The ANSI/HFES 100-2007 standard by the Human Factors and Ergonomics Society recommends adjustable seat pan angles 0°-4°, seat pan backrest of not less than 90° and seat pan recline not exceeding 25° from the vertical [10]. ...
This paper presents a posture assessment tool which utilizes the depth sensing techniques of a 3D imaging sensor for ergonomic risk assessment of seated worker’s postures during controlled manual handling tasks. The tool, which has been developed to utilize the manual handling guidelines by the Health and Safety Regulators of some selected countries to measure and assess the postures of the upper bodies of Operators, is tested to ascertain its effectiveness in assessing seated postures. The tool offers real-time posture assessment with real-time feedback to inform Operators on when to adjust awkward seated postures. An experiment has been performed to record, assess and display the work postures of some seated Operators in real-time with ‘Good’ and ‘Awkward’ postures identified with real-time feedback provided to the Operators. Results show that the tool can assess seated work postures in real-time which helps to reduce the rate of occurrence of Work-Related Musculoskeletal Disorders.
... In summary, failing to evaluate the ergonomic instruments through the IRT methods ends up not guaranteeing the measurements they were designed to do, nor what items should be inserted or removed from the instruments to improve their psychometric properties, nor that the parameters of the items are independent of the individuals who form the sample. Considering these factors, new ergonomic instruments such as the questionnaire to evaluate the ergonomic requirements of tablet armchairs(TIRLONI et al, 2016) and discomfort / comfort of aircraft seat(MENEGON et al., 2016) are already ...
This research aims to measure the ANEEL Consumer Satisfaction Index (IASC) of CELESC electricity distributor through the application of the Item Response Theory. The IASC is an indicator that allows evaluates the satisfaction of the residential consumer with the services provided by the electricity distributor with the intention of stimulating continuous improvement. The data set of the satisfaction survey fulfilled out by ANEEL in 2020 is quantitative and was obtained through secondary sources. It was possible to test the validity and internal consistency of the items and through the Item Response Theory (IRT) an interpretable scale was built to measure the level of consumer satisfaction. It was possible to calculate and explain the information curves of the items and the test, as well as demonstrate the gain that can be obtained with its application to measure the level of consumer satisfaction. The satisfaction level scale was created in five categories: “very dissatisfied, dissatisfied, neither dissatisfied/nor satisfied, satisfied and very satisfied. The results showed that 1.05% of consumers are very dissatisfied, 15.85% are dissatisfied, 55.75% are neither dissatisfied/nor satisfied with the company; 26.31% are satisfied, and 1.05% are very satisfied with the energy distributor. The created scale allows the energy distributor to monitor the measured indicators and evaluate the evolution of consumer satisfaction. In addition, managers to develop strategies to improve the level of consumer satisfaction can use the model created, to achieve continual improvement in service delivery of the Electricity Distributor.
Aim
Musculoskeletal pains are often due to the ergonomics risk factors of the environment. Furthermore, as the routine sport training involving aerobic exercises provides a fit and adequate musculoskeletal structure, doesn’t affect the core stabilization muscles. Therefore, strengthless muscles and unstable lumbo-pelvik musculoskeletal system provoke pain in related anatomical region. In this context, we aimed to evaluate the statistical relationship between the ergonomic approach and lack of core stabilization exercises with musculoskeletal pains of athletes.
Material and methods
A total of 80 athletes participated in our work. Standardized ergonomic muscle and skeletal system pains questionnaires were applied to participants. Correlation tests were performed and statistically evaluated by comparing the parameters such as gender, age range, height, weight, and sports age period. Also 52,25% (n: 41) of athletes complain of lumbar pain. Core stabilization exercises were performed during six weeks. Initial VAS and final VAS were analyzed.
Results
In total, 88,75% (n = 71) of participants had complaints of pain related to musculoskeletal system during the last week. Age, height, weight, and age of sport showed significant correlations with pain complaints seen in some body regions as topographically (P < 0.05). Also, a significant decrease of pain was observed after six weeks. Ergonomic conditions, incorrect static posture and core stability may be influential factors in the formation of musculoskeletal system diseases. The ergonomic change needs to involve both sports methods and working environments. Also, including core stabilization exercise in routine training program may ensure a pain decrease and an increase in performance.
