Evaluation of the Indonesian National Standard for elementary school furniture based on children's anthropometry

Development of a sitting posture monitoring system for children using pressure sensors: An application of convolutional neural network

BACKGROUND

Today, sedentary lifestyles are very common for children. Therefore, maintaining a good posture while sitting is very important to prevent musculoskeletal disorders. To maintain a good posture, the formation of good postural habit must be encouraged through posture correction. However, long-term observation is required for effective posture correction. Additionally, posture correction is more effective when it is performed in real time.

OBJECTIVE

The goal of this study is to classify nine representative sitting postures of children by applying a machine learning technique using pressure distribution data according to the sitting postures.

METHODS

In this study, a customized film-type pressure sensor was developed and pressure distribution data from nine sitting postures was collected from seven to twelve year-old children. A convolutional neural network (CNN) was applied to classify the sitting postures and three experiments were conducted to evaluate the performance of the model in three applicable usage scenarios: usage by familiar identifiable users, usage by familiar, but unidentifiable users, and usage by unfamiliar users.

RESULTS

The results of our experiments revealed model accuracies of 99.66%, 99.40%, and 77.35%, respectively. When comparing the recall values for each posture, leaning left and leaning right postures had high recall values, but good posture, leaning forward, and crossed-legs postures had low recall values.

CONCLUSION

The results of experiments indicated that CNN is an excellent classification method to classify the posture when the pressure distribution data is used as input data. This study is expected to contribute a development of system to aid in observing the natural sitting behavior of children and correcting poor posture in real time.

Anthropometric perspective to classroom furniture ergonomics and the need for standards in Nigerian schools

BACKGROUND: Classroom furniture designs have been implicated in musculoskeletal disorders among school age persons due to high level mismatches between the furniture dimensions and users’ anthropometrics. OBJECTIVE: The objective of the study was to analyze classroom furniture ergonomics at selected primary, secondary and tertiary educational institutions in Nigeria and to understand if there are noticeable patterns in the match/mismatch. METHOD: Anthropometric measures relevant to furniture design were obtained from primary and secondary school children as well as from university undergraduates. The dimensions of classroom furniture available to the participants were also taken and an assessment of the suitability of the furniture was completed. RESULT: The ergonomic evaluation of the classroom furniture available to the study participants revealed enormous discrepancies between the furniture dimensions and the anthropometric measures of the users. In addition, a pattern was observed in the way the matches/mismatches occurred. The furniture dimensions that matched majority of the users tend to match across the three categories and those that did not match majority of the students, also followed the same pattern. CONCLUSION: The study presents remarkably high levels of mismatches between classroom furniture and users’ anthropometrics and therefore calls for a review of the policies for classroom furniture design in Nigeria, if at all any policy exists.

Validation of Two Instruments for the Correct Allocation of School Furniture in Secondary Schools to Prevent Back Pain

BACKGROUND

Back pain is common in secondary school students. If we adjust the school furniture to the anthropometric characteristics of the pupils, we will improve their posture and reduce back pain. There is a high degree of mismatch between the furniture used by students and that which should be used. The objectives of this research are to discover the degree of mismatch and validate two instruments that allow a correct allocation of the furniture.

METHODS

The selected sample was 132 secondary students (14.08 ± 1.10 years). An anthropometer was used to determine the ideal height of the chair and table; data were taken from body segments. The recorded values were compared with those obtained by the two measurement instruments to be validated. Inter-measurer and intra-measurer reliability and validation were performed using t-tests and Pearson's coefficient, respectively. Different analysis techniques were used: descriptive, one-way ANOVA, t-test, and effect size. The established level of significance was ρ < 0.05.

RESULTS

The mismatch between the anthropometric dimensions of the students and the existing furniture in the classrooms was 98.5 % for the chairs and 100 % for the tables. The correlational analysis of the instruments to be validated shows an r = 0.993 in the chair and r = 0.996 in the table.

CONCLUSIONS

There is a high degree of mismatch between the furniture and the anthropometric characteristics of the students. The proposed furniture allocation instruments are adequate.

Comparison of classroom furniture to anthropometric measures of Turkish middle school students

BACKGROUND

The match between classroom furniture and students' anthropometry is an important factor in students' academic performance.

OBJECTIVE

Our aim was to investigate the ergonomic suitability of the classroom furniture to the students, and to propose design suggestions for both desks and chairs.

METHODS

We analyzed the ergonomics of classroom furniture that students aged 10-14 years old in Turkey currently use. To this end, we selected Maltepe Primary Education School, one of the largest schools in the Çankaya district of Turkey's capital city, Ankara, in which to conduct the study. A sample of 119 students was selected, and seven anthropometric measurements were taken for each of these students. We then calculated five relationships between the dimensions of the furniture and the students' anthropometric measures.

RESULTS

We observed high levels of mismatch rates, with an average of 66.6%and high values of over 95%for the relations of two furniture measures, seat depth (related with buttock-popliteal length) and seat-to-desk height (related with elbow height, sitting). Each anthropometric measure was applied a fit probability distribution, and based on those distributions; we suggested the most appropriate classroom furniture dimensions in order to maximize suitability of the furniture to the anthropometric measures in terms of fixed-size (i.e., non-adjustable) classroom furniture.

CONCLUSIONS

High mismatch rates can be reduced by 52.0%on average based on the classroom furniture dimensions suggested in this study.

Designing School Tables and Chairs based on Anthropometry of Elementary School Students in Surabaya

 Introduction: School tables and chairs are needed amongst many other facilities which support the teaching and learning activities. Uncomfortable tables and chairs can cause health problems. The purpose of this study is to design school table and chair sizes in accordance with anthropometry of elementary school students, so the tables and chairs do not cause health problems for children. Methods: The population used in this study was 72 students of elementary school students in Surabaya, and the sample size was 61 students. The sampling method used in this research was a simple random sampling. The anthropometric data measured were shoulder height in the sitting position, elbow height in the sitting position, popliteal-buttock length, knee height, popliteal height, shoulder width, and distance from elbow to fingertips. Meanwhile, the dimensions of tables and chairs measured were chair height, chair width, back length, back height, table height, table width, and underneath desk height. Results: The results of the research show that the sizes of existing tables and chairs are mismatched with student anthropometry. There are 7 dimensions of proposed table and chair sizes which are based on anthropometric data. Specifically, the chair height is 33.25 cm, chair width is 33.25 cm, backrest length is 46.50 cm, backrest height is 49.60 cm, table height is 56.85 cm, table width is 39.05 cm, and underneath desk height is 47 cm. Conclusion: The sizes of existing tables and chairs still need improvement in all dimensions based on the students’ anthropometric measurements.Keywords: anthropometry, chair, elementary school students, table 

Developing a Multi-Criteria Decision Making approach to compare types of classroom furniture considering mismatches for anthropometric measures of university students

The mismatch between students’ anthropometric measures and school furniture dimensions have been investigated in many countries. In Iran, collegians spend at least a quarter of the day hours at university in the sitting position, so it is essential to evaluate furniture mismatch among university students. In Iranian universities, the use of chairs with an attached table is widespread, while the study of mismatches in these chairs among the collegian community is rare. This study was aimed to compare and rank different classroom furniture types based on the mismatch between collegians’ anthropometric measures and the dimensions of classroom furniture among Industrial Engineering students by developing a Multi-Criteria Decision Making approach in an integrated Methodology. The sample consisted of 111 participants (71 males, 40 females). Ten anthropometric measures were gathered, together with eight furniture dimensions for four types of chairs. Mismatch analyses were carried out using mismatch equations, and the Simple Additive Weighting method was used as a base method to solve the decision-making problem. The results indicated that Underneath Desk Height and Seat to Desk Clearance showed the highest levels of the match, while Seat Width presents the highest levels of low mismatch. According to the results, Type 1 and Type 3 were the best current classroom furniture. The Sensitivity Analysis was performed in two ways: changing the weights of criteria in nine scenarios and comparing the results with five other MCDM methods. The proposed MCDM approach can be used widely in furniture procurement processes and educational environments.

The effect of furniture intervention on the occurrence of musculoskeletal disorders and academic performance of students in North-West Nigeria

BACKGROUND

Mismatch between classroom furniture and the students' anthropometry have been identified as a major cause of musculoskeletal disorders (MSDs) among students. Such discomforts can affect students' performance.

OBJECTIVE

This paper is aimed at investigating the prevalence of MSDs and the effect of furniture intervention among students of tertiary institutions in Northwest Nigeria.

METHODS

The Cornell's MSD questionnaire was used to investigate the prevalence of MSDs in twelve body regions of students aged between 16 and 25 years. Eleven students' anthropometric dimensions were also measured and used to compute the ergonomically compliant furniture dimensions for the participants. A new set of furniture was introduced, and the questionnaire was used to investigate if the intervention made was significant or not. The academic performance of some of the students before and after the intervention was analyzed using the t-test statistical technique.

RESULT

None of the furniture in use was suitable for the majority of the students. MSDs prevalence ranges from 14% to 67.3% among the body regions with the students reporting that low back pain is the most prevalent (67.3%), severe (19.4%) and interfering with their studies (15.8%). The intervention also reduced MSDs in all body regions except at the upper arm and the right side of the forearm. Only sitting, knee, and popliteal heights were significantly associated with MSD occurrence. There was also a significant improvement in the students' academic performance after the intervention (t = -3.239, p = 0.002).

CONCLUSION

The limited success of the intervention is an indication of the need to carry out a more holistic intervention that incorporates other inputs such as continuous enlightenment and classroom facility design.

Evaluation of the guidelines and children's ability to select the anthropometrically recommendable height of school furniture: A case study of Korean primary school children

BACKGROUND

The use of school furniture with a height that is anthropometrically mismatched can lead children into taking awkward postures while sitting. In Korea, desks and chairs for primary schools have seven different height levels, and these levels are regulated by the national standard KSG-2010. These levels serve to accommodate children of all heights, but the choice problem remains because of the many alternatives.

OBJECTIVE

This study evaluates the anthropometric feasibility of the currently used guidelines for the selection of height level for Korean primary school furniture. In addition, we examine children's ability to select anthropometrically recommendable desk and seat heights.

METHODS

In study 1, anthropometric data from 2005 Korean children were acquired and a mismatch analysis was performed under the assumption that children were paired with the height level recommended by the guidelines. In study 2, we conducted a desk and seat height selection experiment that included 36 children.

RESULTS

The results of study 1 revealed that about three quarters of children could be matched by following the guidelines. The results of study 2 showed that a quarter of children selected matchable desk and seat heights by themselves. We developed new guidelines using classification algorithms based on the employed data in study 1, and it was confirmed that the new guidelines could significantly increase the degree of match.

CONCLUSION

This study confirmed that the currently used guidelines need to be revised and that children had difficulty in selecting the appropriate height of school furniture by themselves. The new guidelines suggested in this study are expected to contribute to the correct usage by Korean primary school children.

Classroom Furniture Mismatch and Back Pain Among Adolescent School-Children in Abha City, Southwestern Saudi Arabia

Objective: To explore the potential classroom furniture mismatch with students’ anthropometric measurements and back pain related to sitting for extended periods. Methods: This cross-sectional study was carried out on all twelve male and female intermediate and secondary schools located in Abha city. Anthropometric and classroom furniture measurements were assessed, and the mismatch was determined using standardized methods. Students were also screened for back pain related to long sitting at school. Results: A total number of 879 students was selected. The study revealed seat height mismatch in both intermediate, and secondary school of 84.3%, and 75.6%, respectively. Seat depth mismatch was 74.0% in intermediate schools and reached 84.5% in secondary schools. The desk height was improper for 94.1%, and 82.3% of students in intermediate, and secondary schools, respectively. The levels of mismatch differ significantly by grade level and gender. A prevalence of 10.8% of back pain related to long sitting at school was found. In multivariable logistic regression, males, intermediate school children, and the presence of buttock-popliteal length/seat depth mismatch were significantly associated with pain. On the other hand, practicing exercise was a significant protective factor. Conclusions: There is a prevalent mismatch between students’ dimensions and existing schools’ furniture. School furniture providers should take in consideration the average Saudi students’ dimensions, while designing school furniture especially for males, and at intermediate schools, or provide schools with adjustable seats and desks.