The anthropometric match between high school learners of the Cape Metropole area, Western Cape, South Africa and their computer workstation at school

Ergonomic evaluation of school furniture in Slovenia: From primary school to university

BACKGROUND:

Adequate school furniture is important to prevent musculoskeletal discomfort among students.

OBJECTIVE:

The aim of the study was to assess the suitability of school furniture compared to body dimensions of students.

METHODS:

A cross-sectional study included a total of 442 students from primary school, secondary school, and university. Nine body dimensions along with five furniture dimensions were measured and equations for mismatch criteria were applied.

RESULTS:

In primary school, differences in body dimensions were more evident among students of different age, while in secondary school and university, differences between male and female students became more apparent. The mismatch for desk height ranged from 100.0% at primary school to 48.0% at university. Similarly, the seat height mismatch was the most evident in primary school (89.7% –94.6%), lower at university (52.0%) and the lowest in secondary school (18.0%). The seat depth mismatch was present among all groups, ranging from 23.1% to 40.4%, and was in general more pronounced in males. Seat to desk clearance mismatch was the most evident among secondary school students. In primary school, seat and desk height were generally too high for most of students.

CONCLUSIONS:

Specific differences in body dimensions among groups of students of different age and gender were observed and a high student-furniture mismatch was identified in all educational institutions. Implementation of adjustable school furniture, covering at least two size marks, is needed to provide ergonomic and healthy learning conditions and to further enhance the comfort and well-being of students in the classroom.

Teachers' Perspective on Strategies to Reduce Sedentary Behavior in Educational Institutions

Standing desks and physical activity breaks can counteract the negative consequences of sedentarism at school. However, the implementation of these strategies should not restrict the pedagogical process. The aim of this study was to assess teachers’ perspectives on strategies to reduce sedentary behavior (SB) of students in the classroom. An online survey was conducted, and the answers were analyzed using descriptive statistics and frequency distribution. The relationships between the variables were assessed using Spearman’s coefficient and a chi-square test. Most teachers believed that a student–furniture mismatch was present. The most common reasons given for not using standing desks were concerns about desks being uncommon and their potential to disrupt the class. However, the majority of the teachers believed it feasible to perform physical activity (PA) breaks during classes. Further intervention studies are needed to determine for which courses the use of standing desks are feasible, for what time periods standing desks should be used, and the appropriate number and layout of standing desks in classrooms.

Data-Driven Design Solution of a Mismatch Problem between the Specifications of the Multi-Function Console in a Jangbogo Class Submarine and the Anthropometric Dimensions of South Koreans Users

The naval multi-function console provides various types of information to the operator. It is equipment that is key for submarine navigation, and fatal human errors can occur due to the mismatch between the console specifications and the operator’s body size. This study proposes a method for deriving console specifications suitable for the body size of Korean users. The seat height, seat width, seat depth, upper edge of backrest, and worktable height were selected as the target design variables. Using six anthropometric dimensions, a mismatch equation for each target design variable was developed. Anthropometric measures of 2027 Korean males were obtained, and the optimal specifications of the console were derived via an algorithmic approach. As a result, the match rate, considering all the target design variables, was improved from 2.57% to 76.96%. In previous studies and standards, the optimal console specifications were suggested based on the anthropometric data of a specific percentile of users, and it was impossible to quantitatively confirm the suitability of the console design for the target users. However, the method used in this study calculated the match rate using the mismatch equation devised for comfortable use of the console and a large amount of anthropometric data that represented the user population, and therefore the improvement effect of the recommended specification can be directly identified when compared to the current specifications. Moreover, the methodology and results of this study could be used for deciding the specifications of multi-function consoles in several fields, including nuclear power plants or disaster situation rooms.

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.

A review of the methodology and applications of anthropometry in ergonomics and product design

Anthropometry is a key element of ergonomic studies for addressing the problem of fitting the tasks/products to user characteristics, but there is a gap between anthropometric data and their application for designing ergonomic products and environments. This research was conducted to review the literature on the methodology and applications of anthropometry for the ergonomic design of products and environments, and to identify where further research is needed to improve its application and evaluation protocols. One hundred and sixteen papers meeting the inclusion criteria were reviewed. Although a number of anthropometric investigations have been conducted to improve the design of products/environments for different users, further research seems to be necessary, particularly for special groups, such as children, the elderly and people with disabilities. Different anthropometric measurement methods/techniques and fitting criteria are discussed regarding their applicability for various design applications. This review also highlights methodological issues (sampling considerations and prototype evaluation and testing) that should be considered in future research to ensure a user-centred approach of the design process. Practitioner Summary: A literature review was conducted on the methodology and applications of anthropometry for the ergonomic design of products/environments. This review emphasises the need for anthropometric research to design for special groups, such as children, the elderly and people with disabilities, and methodological issues that should be considered in future research. Abbreviations: 1D: one-dimensional; 2D: two-dimensional; 3D: three-dimensional; HF/E: Human Factors/Ergonomics; PCA: Principal Components Analysis; CA: Cluster Analysis; DHM: Digital Human Modelling.

The amount of postural change experienced by adolescent computer users developing seated -related upper quadrant musculoskeletal pain

BACKGROUND

Improved techniques of measuring sitting posture have not led to a more comprehensive understanding of poor posture, nor its association with pain. There is also an evidence gap regarding critical thresholds of sitting postural change over time related to pain production. This paper describes postural angle changes over a 12-month period, and describes the process of placing defensible cut-points in the angle change data, to better understand associations between posture change over time, and onset of upper quadrant musculoskeletal pain (UQMP).

METHODS

This paper reports on data captured at baseline and 12-month follow-up, in adolescents in school using computers. Four sitting postural angles, head flexion (HF), neck flexion (NF), craniocervical angle (CCA) and trunk flexion (TF), and self-reported seated UQMP in the previous month were captured at each time-point. Research questions were: 1) What is the magnitude and direction of change in each postural angle over 12 months? 2) What are best cut-points in the continuous posture change distribution to most sensitively test the association between posture change and UQMP? 3) Is gender-specific cut-points required? The 12-month posture angle change data was divided into quintiles (0-20th%; 21-40^th%, 41-60^th%, 61-80^th%, >80^th%), and the odds of UQMP occurring in each posture change quintile were calculated using logistic regression models.

RESULTS

Two hundred and eleven students participated at baseline, of which 153 were followed-up at one year. Both males and females with postural change into extension (which represents lesser flexion range) were more at risk for the development of UQMP, than any other group. The best cut-point for HF was 40^th% (≤-3.9°), NF was 20th% (≤-2.9°) and TF was 40^th% (≤-1.1°). For CCA however, change at or beyond 40^th % for extension or beyond 60% for flexion was associated with UQMP.

CONCLUSIONS

Identification of critical postural angle change cut-points assists in considering the pain-producing mechanisms for adolescents using desk top computers.

A literature review of anthropometric studies of school students for ergonomics purposes: Are accuracy, precision and reliability being considered?

BACKGROUND

Despite offering many benefits, direct manual anthropometric measurement method can be problematic due to their vulnerability to measurement errors.

OBJECTIVE

The purpose of this literature review was to determine, whether or not the currently published anthropometric studies of school children, related to ergonomics, mentioned or evaluated the variables precision, reliability or accuracy in the direct manual measurement method.

METHODS

Two bibliographic databases, and the bibliographic references of all the selected papers were used for finding relevant published papers in the fields considered in this study.

RESULTS

Forty-six (46) studies met the criteria previously defined for this literature review. However, only ten (10) studies mentioned at least one of the analyzed variables, and none has evaluated all of them. Only reliability was assessed by three papers. Moreover, in what regards the factors that affect precision, reliability and accuracy, the reviewed papers presented large differences. This was particularly clear in the instruments used for the measurements, which were not consistent throughout the studies. Additionally, it was also clear that there was a lack of information regarding the evaluators' training and procedures for anthropometric data collection, which are assumed to be the most important issues that affect precision, reliability and accuracy.

CONCLUSIONS

Based on the review of the literature, it was possible to conclude that the considered anthropometric studies had not focused their attention to the analysis of precision, reliability and accuracy of the manual measurement methods. Hence, and with the aim of avoiding measurement errors and misleading data, anthropometric studies should put more efforts and care on testing measurement error and defining the procedures used to collect anthropometric data.

Ergonomic behaviour of learners in a digitally driven school environment: Modification using an ergonomic intervention programme

Background

Computer use is increasing amongst adolescents and so is the potential for related musculoskeletal pain and postural changes. The cumulative effect of this technology-induced, sedentary lifestyle leads to poor posture, pain, repetitive strain injury and dysfunctional movement patterns.

Objectives

The purpose of this study was to establish the effect of a computer-related ergonomic intervention for adolescents in a school environment on posture and ergonomic behaviour.

Methods

All Grade 8 learners at two randomly selected private schools in Johannesburg were invited to participate in the study (n = 127). A controlled trial compared an intervention group with a control group. The computer usage questionnaire and rapid upper limb assessment (RULA) were assessed at baseline, 3 and 6 months post-intervention. The intervention consisted of a participatory educational programme. An intention-to-treat analysis was undertaken. Alpha level was set at p = 0.05. Descriptive statistics (frequencies and percentages) and between-group analysis of variance, determined differences in the number of participants in the RULA action levels between groups after the intervention and the comparison of positions and type of computer.

Results

At 6 months post-intervention, there were no participants in action level (AL) 4 and the number of participants in AL 3 had reduced from 26.2% at baseline to 14.8% in the intervention group (p < 0.001). The control group RULA scores worsened over the period of 6 months. Although the learners were still not in an ’acceptable’ range of postural positions, there was a significant improvement between the pre-intervention and post-intervention stage (p < 0.001).

Conclusion

These findings demonstrate the effect of an ergonomic intervention and its sustainability over 6 months.

Clinical implications

The clinical contribution of this study to our healthcare system is that through the early identification and intervention of the poor ergonomics in a school environment, a positive impact on reducing poor postural behaviour amongst learners can be achieved.

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

In Indonesia, National Standardization Agency of Indonesia issued the Indonesian National Standard SNI 12-1015-1989 and SNI 12-1016-1989 to define the type of furniture dimensions that should be used by children in the elementary school level. This study aims to examine whether the current national standards for elementary school furniture dimensions issued by National Standardization Agency of Indonesia match the up-to-date Indonesian children's anthropometry. Two types of school furniture, small type (Type I, for grade 1-3) and large type (Type II, for grade 4-6), were evaluated in terms of seat height, seat depth, seat width and backrest height of a chair as well as the height and underneath height of a desk. 1146 students aged between 6 and 12 years old participated in the study. Seven anthropometric measurements were taken including stature, sitting shoulder height, sitting elbow height, popliteal height, buttock-popliteal length, knee height and hip breadth. Based on the standard school furniture dimensions and students' body dimensions, numbers of matches and mismatches between them were computed. Results indicated a substantial degree of mismatch between children's anthropometry and the standard dimensions of school furniture. The standard seat height was not appropriate for students among different grades with the mismatch percentage ranging from 63.4% to 96.7% for Type I and 72.7% to 99.0% for Type II. For desk height, the standard dimensions were not appropriate for students among different grades with the mismatch percentage ranging from 32.3% to 88.9% for Type I and 67.7% to 99.0% for Type II. Apparently, the current standards are out of date and need to be updated. Four different sizes of school furniture were hence proposed to accommodate the variation in students' anthropometry from Grade 1 to Grade 6. The proposed standard dimensions (PrS) of school furniture cover a slightly broader range of age and present a higher cumulative fit than the current standard dimensions (CrS). In addition, a better strategy for sizing can be also developed to fit chairs and desks to a larger number of students.

The influence of school furniture on students' performance and physical responses: results of a systematic review

The purpose of this study was to determine, using a systematic review, whether the design and/or dimensions of school furniture affect the students' physical responses and/or their performance. Of the review studies, 64% presented positive results, i.e. proven effects; 24% presented negative effects or no change/effect; and the remaining 12% showed an unclear effect. The compatibility between school furniture dimensions and students' anthropometric characteristics was identified as a key factor for improving some students' physical responses. Design characteristics such as high furniture, sit-stand furniture, and tilt tables and seats also present positive effects. Finally, we concluded that further research should be conducted exploring various aspects of those variables, particularly focusing on more objective measures complemented by controlled and prospective design. Practitioner Summary: A systematic review of the literature presents a clearly positive effect of school furniture dimensions on students' performance and physical responses. Similar results appeared when school furniture design was tested. However, studying the effects of design and dimensions together produced an unclear positive effect.

Does a prototype 'Experimental' chair facilitate more postural changes in computing adolescents compared to a normal school chair?

BACKGROUND

Prolonged sitting, such as when computing, has been linked to adolescent spinal pain. A chair should fit the user's body dimensions and aid the user in frequently changing sitting posture, rather than support one 'ideal' posture. Such a chair is not currently available to high school learners.

OBJECTIVES

To develop a novel experimental school chair. To determine whether the experimental chair encourages regular small range movement in all directions whilst students work at computers in class. To compare the number of postural changes between the normal static school chair and the experimental chair, whilst students do computing work.

METHODS

A development and validation study was conducted. Twelve high school students were randomly selected from a conveniently selected school. Fifteen minutes of 3D posture measurements were collected in both the prototype and school computer chair. The analysis focused on the frequency of postural movement.

RESULTS

Data of eleven learners were analysed. There were statistically significant increases in the number of postural changes on the 'Experimental' chair compared to the school chair, for both pelvic side-flexion and pelvic rotation (ρ= 0.01).

CONCLUSION

The experimental chair provided more postural movements when compared to the school computer chair. Future studies should use this experimental chair to determine the effect of increased postural movement, of especially the pelvis, on the prevalence and intensity of musculoskeletal symptoms of high school learners in the Cape Metropole area, Western Cape, South Africa.

Analysis of the most relevant anthropometric dimensions for school furniture selection based on a study with students from one Chilean region

Most of the worldwide standards used for furniture selection suggest the use of the Stature of the school children, assuming that all the other anthropometric characteristics will also be appropriate. However, it is important to consider that students' growth differ with age. The aim of this study is to determine if Popliteal Height can be used as a better, or more adequate, measure for classroom furniture selection when comparing with Stature. This study involved a representative group of 3046 students from the Valparaíso Region, in Chile. Regarding the methodology, eight anthropometric measures were gathered, as well as six furniture dimensions from the Chilean standard. After assigning the level of school furniture using Stature and Popliteal Height to each of the students, six mismatch equations were applied. The results show that when using Popliteal Height, higher levels of match were obtained for the two more important furniture dimensions. Additionally, it also presents a better cumulative fit than Stature. In conclusion, it seems that Popliteal Height can be the most accurate anthropometric measure for classroom furniture selection purposes.

The effect of secular trends in the classroom furniture mismatch: support for continuous update of school furniture standards

In order to create safer schools, the Chilean authorities published a Standard regarding school furniture dimensions. The aims of this study are twofold: to verify the existence of positive secular trend within the Chilean student population and to evaluate the potential mismatch between the anthropometric characteristics and the school furniture dimensions defined by the mentioned standard. The sample consists of 3078 subjects. Eight anthropometric measures were gathered, together with six furniture dimensions from the mentioned standard. There is an average increase for some dimensions within the Chilean student population over the past two decades. Accordingly, almost 18% of the students will find the seat height to be too high. Seat depth will be considered as being too shallow for 42.8% of the students. It can be concluded that the Chilean student population has increased in stature, which supports the need to revise and update the data from the mentioned Standard.

PRACTITIONER SUMMARY

Positive secular trend resulted in high levels of mismatch if furniture is selected according to the current Chilean Standard which uses data collected more than 20 years ago. This study shows that school furniture standards need to be updated over time.

Applying different equations to evaluate the level of mismatch between students and school furniture

The mismatch between students and school furniture is likely to result in a number of negative effects, such as uncomfortable body posture, pain, and ultimately, it may also affect the learning process. This study's main aim is to review the literature describing the criteria equations for defining the mismatch between students and school furniture, to apply these equations to a specific sample and, based on the results, to propose a methodology to evaluate school furniture suitability. The literature review comprises one publications database, which was used to identify the studies carried out in the field of the abovementioned mismatch. The sample used for testing the different equations was composed of 2261 volunteer subjects from 14 schools. Fifteen studies were found to meet the criteria of this review and 21 equations to test 6 furniture dimensions were identified. Regarding seat height, there are considerable differences between the two most frequently used equations. Although seat to desk clearance was evaluated by knee height, this condition seems to be based on the false assumption that students are sitting on a chair with a proper seat height. Finally, the proposed methodology for suitability evaluation of school furniture should allow for a more reliable analysis of school furniture.

The spinal posture of computing adolescents in a real-life setting

Background

It is assumed that good postural alignment is associated with the less likelihood of musculoskeletal pain symptoms. Encouraging good sitting postures have not reported consequent musculoskeletal pain reduction in school-based populations, possibly due to a lack of clear understanding of good posture. Therefore this paper describes the variability of postural angles in a cohort of asymptomatic high-school students whilst working on desk-top computers in a school computer classroom and to report on the relationship between the postural angles and age, gender, height, weight and computer use.

Methods

The baseline data from a 12 month longitudinal study is reported. The study was conducted in South African school computer classrooms. 194 Grade 10 high-school students, from randomly selected high-schools, aged 15–17 years, enrolled in Computer Application Technology for the first time, asymptomatic during the preceding month, and from whom written informed consent were obtained, participated in the study. The 3D Posture Analysis Tool captured five postural angles (head flexion, neck flexion, cranio-cervical angle, trunk flexion and head lateral bend) while the students were working on desk-top computers. Height, weight and computer use were also measured. Individual and combinations of postural angles were analysed.

Results

944 Students were screened for eligibility of which the data of 194 students are reported. Trunk flexion was the most variable angle. Increased neck flexion and the combination of increased head flexion, neck flexion and trunk flexion were significantly associated with increased weight and BMI (p = 0.0001).

Conclusions

High-school students sit with greater ranges of trunk flexion (leaning forward or reclining) when using the classroom computer. Increased weight is significantly associated with increased sagittal plane postural angles.

Frequency of postural changes during sitting whilst using a desktop computer--exploring an analytical methodology

BACKGROUND

Dynamic movement whilst sitting is advocated as a way to reduce musculoskeletal symptoms from seated activities. Conventionally, in ergonomics research, only a 'snapshot' of static sitting posture is captured, which does not provide information on the number or type of movements over a period of time. A novel approach to analyse the number of postural changes whist sitting was employed in order to describe the sitting behaviour of adolescents whilst undertaking computing activities.

METHODS

A repeated-measures observational study was conducted. A total of 12 high school students were randomly selected from a conveniently selected school. Fifteen minutes of 3D posture measurements were recorded to determine the number of postural changes whilst using computers.

RESULTS

Data of 11 students were able to be analysed. Large intra-subject variation of the median and IQR was observed, indicating frequent postural changes whilst sitting.

CONCLUSION

Better understanding of usual dynamic postural movements whilst sitting will provide new insights into causes of musculoskeletal symptoms experienced by computer users.