Abstract
BACKGROUND:
Primary school children spend quite a lot of time sitting in classrooms. For this reason, it is necessary to make a scientific analysis of children’s body dimensions and compare them with the furniture dimensions where they sit.
OBJECTIVES:
The main aim of this paper is to present anthropometric data for pupils in primary schools in the Republic of Kosovo and give recommendations for school furniture design.
METHODS:
Measurements were made in the public schools of four different regions in the Republic of Kosovo. The study includes 720 children from 12 different elementary schools with first and fifth graders (6–11 years old). Twelve body parts were measured: Stature, sitting height, shoulder height, lower leg length, hip breadth, elbow height, buttock-popliteal length, thigh clearance, eye height, shoulder breadth, and knee height. The descriptive data are calculated in terms of average, standard deviation, and 5th, 50th and 95th percentile.
RESULTS:
We recommend that the competent authorities in the Republic of Kosovo consider improving the infrastructure of primary schools in terms of furniture size according to the findings presented in this study.
CONCLUSIONS:
The information presented in this paper on pupils’ anthropometry and the proposed dimensions for school furniture can be used by various bodies in Kosovo including, but not limited to: Ministry of Education Science and Technology, Ministry of Trade and Industry of Kosovo and furniture manufacturing industries as basic information for suitable furniture design for primary school children, as well as school principals to help in furniture selection.
Introduction
Growth is defined as physical body change [1] that usually takes place from birth to the age of 18–23. During this period, the human body undergoes significant changes. For children in the Republic of Kosovo, the age of six represents a great change in their lives. At this age, they start school and spend quite a lot of time sitting on school benches. Being seated on a bench for a long time usually leads to children having a drooping posture, which consequently causes extreme strain on the muscles, ligaments and in particular the neck and spine disc [2–4].
Static posture and sitting in a bent position for a long time, as elementary schoolchildren tend to do, creates a conflict between the natural tendency towards unrestricted physical movement and the need to maintain a seated position for a longer period of time [5].
During school time, most activities such as reading, writing and others are performed in a sitting position. According to Castellucci et al. [6], children spend approximately 25% of the day at school, and around 80% of that time they spend sitting down on seats doing their school work.
In Kosovo, pupils from 1st to 5th grade spend about one-fifth (around 22%) of the day in school benches. Various authors have concluded that children during their time in school for every 90 minutes, they are seated for more than 60 minutes [7]. Considering the fact that, while at school, children have to stay seated for long stretches of time, the relevant authorities should take measures to ensure a comfortable stay for children.
Discrepancies between pupils’ anthropometric dimensions sizes of school furniture have been reported in many countries such as the United States [8], India [9], Indonesia [10], Turkey [11], Greece [12, 13], Chile [14], United Arab Emirates [15], Saudi Arabia [16], Korea [17] and elsewhere around the world. Discrepancies between the dimensions of school furniture and the pupils’ anthropometric dimensions have been reported as a serious problem for the abovementioned countries.
The discrepancy between pupils’ anthropometric dimensions and school furniture causes serious problems for pupils. In this regard, researchers have given their opinions. According to Murphy et al. [18], in British schools, there is a correlation between furniture inadequacy and pain in different parts of the body (including neck, back, waist, etc.). Some countries decide to use certain sets of standards to define the type of furniture dimensions that should be used according to pupils anthropometric characteristics [19].
These standards exist in Kosovo as well, and they clearly define the type and dimensions of furniture in accordance with the characteristics of pupils (Kosovo Standardization Agency 2019, SK EN 1729-1:2015/AC:2019). Due to the complexity of design problems, innovative solutions for school furniture should be found by establishing multidisciplinary teams composed of orthopedic doctors, rehabilitation experts, teachers, psychologists, constructors, technologists, environmentalists, economists and, of course, designers [20, 21]. Recent studies have shown an increase in musculoskeletal problems in primary school children [22].
If, through improper anthropometric design, the chair did not allow to the majority of users to, in fact, have foot or back contact with other surfaces, body instability would be increased, and additional muscular force would have to be introduced in order to maintain proper equilibrium. The greater the degree of muscular force or control required, the greater the fatigue discomfort [23]. According to chair height researchers [23], “by and large, however, a tall person would be far more comfortable using a chair with a low seat height than a short person using a chair with a seat height that is too high”. School furniture that provides a comfortable sitting position for elementary school pupils and better concentration during classes should be considered [24]. Other researchers have also given similar views on the impact of furniture ergonomics on improving the quality of learning [25]. Anthropometric measurements are therefore an important consideration in designing ergonomically appropriate furniture for school children [26].
The availability of data on anthropometric measures, particularly for schoolchildren, is very limited in the Republic of Kosovo, and as a result, school furniture design is not based on anthropometric principles and according to standards. Thus, the study is focused on data collection to determine the potential discrepancy of dimensions between school furniture and the characteristics of primary school children in the Republic of Kosovo.
Methods
Participants
The participants in the study were children from four different cities in the territory
of the Republic of Kosovo (Table 1). The sample size was calculated through Slovin’s formula (1) [28]:
Where “n” is desired sample size; “N” is total population group, and “e” is the level of precision.
The number of children by grades in primary schools in the Republic of Kosovo [27]
In our study, the level of precision is±4%. Therefore, N = 622. According to equation 1, the calculated sample size was 622. The number of children involved in this study were 720. The study involved both males and females from public schools in four different regions in the Republic of Kosovo (Fig. 1).
Regions in which samples were taken.
As can be seen in Table 2, the percentage of females is 49,9% and that of males is 50,1%. The sample size for each grade is 144, and for each region 180.
The number of samples taken in the study by region, age, and gender
Permission to conduct the research was obtained from the school authorities. Schools that declined to participate were replaced by other schools in the same study area. The schools were all selected randomly (three schools in each region). Within each of the 12 selected schools (out of 1058 primary schools of Republic of Kosovo) (Ministry of Education, Science, Technology and Innovation, Statistical Notes 2020/21; https://masht.rks-gov.net/statistikat), 60 children were selected randomly (approximately half of them were male and half female) including 12 children for each grade, 1 to 5 (6–11years).
The division of classes from 1st to 5th grade was done since these groups of pupils had the same shift (i.e., the afternoon shift from 13:00–17:00). It is worth noting that in the morning shift (08:00–13:00) the same classrooms are used by 6th and 9th graders.
Measuring the dimensions of children and school furniture
All anthropometric measurements were collected while pupils were sitting in an erect position on a bench, with knees bent at 90°. Like many other researchers, the body dimensions in this study were also measured using traditional tools [29]. Anthropometric measurements of pupils were made in April-June 2020. During the measurements, the pupils were not wearing shoes, and 2,5 cm are added for the shoes [30, 31]. In accordance with international norms of anthropometric standards (ISO 7250-1, 2017), twelve parts of children’s bodies were measured (Fig. 3, Table 3).
a. and b. Classroom’s furniture, c. and d. Process of measurements.
Anthropometric measurements: 1. Body stature, 2. Sitting height erected, 3. Shoulder height, 4. Popliteal height, 5. Hip breadth, 6. Elbow height, 7. Buttock-popliteal length, 8. Buttock-knee length, 9. Thigh clearance, 10 Eye height, 11. Knee height, 12. Shoulder breadth.
The classroom furniture, which were taken in the study, consist of the same designs but with few changes in dimensions, as can be seen in Table 4.
Dimensions of the classroom furniture measured in four regions taken in the study
Dimensions of the classroom furniture measured in four regions taken in the study
The internal consistency between items in a scale was determined through Cronbach’s alpha. Cronbach’s alpha determined the internal consistency of the collected and analyzed data. Since the alpha value is high, all collected data and analyzed data were high in consistency [29]. As can be seen in Table 5, internal consistency is excellent [7].
Calculation of Cronbach’s alpha includes 12 items
Calculation of Cronbach’s alpha includes 12 items
To determine the anthropometric criteria of furniture, in addition to the data collected, the calculation to determine the degree of their compatibility or discrepancy must also be done. In calculating the data, the theoretical and practical principles of ergonomics have been considered. Using the combination of formulas, the minimum and maximum limits are defined so that any dimension that falls within these values is considered appropriate [12].
The collected data were analyzed by means of descriptive statistics. Values for minimum (min), maximum (max), standard deviation (SD), percentages 5th, 50th, 95th and mean are taken into consideration.
Popliteal height (PH) - seat height criteria
Previous studies show that the seat height needs to be adjusted according to the popliteal height [34, 35], thus allowing the knee to be flexed so that the lower leg forms a maximum of 30° angle relative to the vertical axis. As shown in Equation (2), the seat height needs to be lower than popliteal height so that the lower leg forms a 5–30° angle relative to the vertical and the shin-thigh angle is between 95° and 120° [26]. While researching the literature other criteria for determining seat height may be encountered [13, 21].
Various researchers have given different theories regarding the height of shoes [10, 36].
In this study, according to measures, a 2.5 cm for shoe correction was added to the
popliteal height. Therefore, the match criterion was defined according to Equation (2) [6, 37]:
Where: SH - is seat height and PH - is popliteal height.
To ensure clearance, 5th percentile data should be used to determine the chair height [23].
Seat width discrepancy occurs when hip breadth is greater than the width of the seat
[38]. The seat width should be large enough
to accommodate users with the largest hip breadth [31, 35] and therefore is designed for the 95th percentile of the hip width
distribution or the largest hip width [37, 39–41]. Gouvali and Boudolos [12] recommend that the seat width should be at
least 10% (to accommodate hip breadth) and at the most 30% (for space economy) larger
than the hip breadth, which is shown in Equation
(3):
Where: SW - is seat width and HB - is hip breadth.
According to Panero [23], 5th percentile of data should be used. These will accommodate the greatest number of users: those with shorter buttock-popliteal lengths as well as those with greater lengths. If 95th percentile of data are used, the design will accommodate the users with the larger measurements only, but not those with smaller measurements [23].
The discrepancy is determined when the seat depth is >95% or <80% of the
buttock-popliteal length [8]. Gouvali and
Boudolos [12] have other opinions regarding
seat depth criteria. Thus, the match criterion was determined by Equation (4):
Where: SD is seat depth and BPL is buttock popliteal length.
It is considered appropriate when it is below scapula [39, 42] to facilitate mobility of the trunk and arms [43]. As a result, the equation recommends keeping
the backrest lower than the scapula, or at most on the upper edge of the scapula (60–80%
of shoulder height). Thus, the match criterion was determined by Equation 5 [12]:
Where: BH - is backrest height, and SH - is the shoulder height.
The minimum and maximum value of the desk height was determined according to Gliem et
al. [8]. To determine acceptable desk height
is used the Equation (6).
Where: hE - acceptable elbow rest height with shoulder flexion and abduction [8], hEv - the vertical elbow height, U = hS - hEv - is the upper arm length, θ - is shoulder flexion, β - is shoulder abduction, hS - the shoulder height.
According to Chaffin et al. [44], the minimum
and maximum acceptable angle of the shoulder during writing is 0–25 degree for shoulder
flection and 0–20 degrees for shoulder abduction. For flexion angles, the corresponding
cosines are 1 (0 degrees) and 0.9063 (25 degrees) and for abduction angles, the
corresponding cosines are 1 (0 degrees) and 0.9397 (20 degrees). Given that the cosines
are monotone functions of the angles, a student’s minimum desk height is determined by
the vertical elbow height alone, Equation
7.
The maximum desk height is determined by Parcells et al. [8]:
The maximum and minimum height of the table is calculated from the surface of the floor.
The furniture in all schools that were the focus of this study have approximately the same design and dimensions. Statistical data for grades I–V, including minimum values, maximum, standard deviation, and the percentages of anthropometric data (5th, 50th, 95th) for different parts of the children’s bodies are shown in Tables 6 and 7.
Anthropometric measures of primary school pupils (cm)
Anthropometric measures of primary school pupils (cm)
Calculation of anthropometric data (5th; 50th; 95th centile)
As can be seen in Fig. 4, there is an absolute discrepancy between the anthropometric dimensions of the first graders and the height of the seat. In the second grade, it is seen that only 0,7 % of children have anthropometric dimensions which correspond to the dimensions of the seat height. 99,3% of them do not match the seat height. In the third grade, it is seen that 2,8% of children have anthropometric dimensions which fit the dimensions of the seat height, while 97,2% of children do not fit these dimensions. In the fourth grade, 9,0% of children fit to the dimensions of the chair height, while 91,0% of these children have smaller popliteal buttock dimensions compared to seat height. The seat height dimensions are slightly more proportional to the measurements of fifth graders, where 28,5% of them have dimensions that fit the height of the seat, while 71,5% of them have inconsistencies of anthropometric dimensions. In general, only 8,2% of children in grades I–V have dimensions that fit the dimensions of the seat height.
Mismatch percentage for seat height according to grades I–V.
Referring to data from the scientific literature [23], the height of the seat should be such as to accommodate 5% of the population considered. Recommendation for chair height of children attending schools in the Republic of Kosovo are as follows: for first grades 25,1–28,9 (2,8) cm, for second grades 26,6–30,6 (2,9) cm, for third grades 29,6–34,0 (2,4) cm, for fourth grades 29,4–33,9 (3,0) cm, for fifth grades 33,1–38,0 (2,3) cm.
As can be seen in Table 4, the depth of the chair ranges between 38,0–40,0 mm. In Fig. 5, it is shown that only 2,8% of first graders have a body size that’s appropriate to the dimensions measured in the field. The remaining 97,2% of children do not fit into these dimensions because the depth of the seat is too large. 4,9% of second graders have appropriate body dimensions, while 94,4% of the dimensions do not fit the depth of the chair due to it being too large. 12,7% of third grade children have appropriate dimensions, while 87,3% of them mismatch the dimensions in terms of large chair depth. 16,2% of fourth grade children fit the dimensions, while 83,8% of children learn in seats that have high depth. 38,7% of fifth grade pupils have anthropometric dimensions, which fit the depth of the seat, 61,3% of them have smaller dimensions compared to the depth of the seat.
Mismatch percentage for seat depth according to grades I–V.
Referring to scientific data [23], the depth of the seat should be such as to accommodate 5% of the population considered. Recommendations for the depth of the seat for children attending schools in the Republic of Kosovo: for the first grade 23,4–27,8 (2,2) cm, for the second grade 25,6–30,4 (2,4) cm, for the third grade 27,2–32,3 (2,1) cm, for the fourth grade 28,8–34,2 (2,1) cm, for the fifth grade 29,4–35,0 (2,6) cm.
In Fig. 6, 100% of first graders have a body size smaller than the width of the seat, only 1,4% of second graders have dimensions larger than seat width. Amongst third graders it can be noted that 0,7% of pupils have body dimensions which fit the width of the seat, while 97,9% of them have smaller dimensions compared to the width of the seat, 1,4% of pupils have larger body dimensions than the seat width. 2,1% of fourth graders have body dimensions that fit the width of the seat, 95,1% of them have smaller body dimensions than the width of the seat and 2,8% of them have dimensions higher than the width of the seat. 2,8% of fifth graders have body dimensions that fit the width of the seat, 91,0% have a body width less than the width of the seat and 6,3% have body dimensions larger than the width of the seat.
Mismatch percentage for seat width according to grades I–V.
Ansari et al. [45] recommend that the width of the seat should be such as to accommodate 95% of the population considered. Recommendations for the width of the seat for children attending schools in the Republic of Kosovo: for the first grade 32,9–38,9 (3,6) cm, for the second grade 34,0–40,2 (3,4) cm, for the third grade 36,3–42,9 (3,7) cm, for the fourth grade 38,3–45,2 (3,8) cm and for the fifth grade 41,5–49,1 (4,3) cm.
In general, there is agreement between researchers that the primary purpose of the backseat of chair is to provide lumbar region support [46, 47]. Adequate lumbar support is the most crucial element of a backrest. Inadequate lumbar support places excess pressure on the spine. Figure 7 shows that 6,3% of children fit the backrest height, while 93,8% of first graders do not fit the backrest height because it is too high. Amongst second-grade pupils, it is noted that 10,4% of children fit the dimensions of the backrest height, while 89,6% have smaller dimensions compared to backrest height. The third graders fit 24,3% of dimensions, while the inconsistency to the backrest height is 75,7%. The fourth graders fit 46,5% of dimensions, while the inconsistency to the backrest height is 53,5%. 79,9% of fifth graders have dimensions that fit the height of the backrest, while 20,1% of them have dimensions smaller than the backrest height.
Mismatch percentage for backrest height according to grades I–V.
Previous studies recommend that the height dimension of the backrest should be 5% [48] of population of the study. Recommendations for backrest height for first grade pupils are 20,9–27,8 (2,4) cm, for the second graders 22,1–29,4 (2,3) cm, for third graders 23,5–31,3 (2,1) cm, for the fourth graders 24,6–32,8 (2,0) cm, for the fifth graders 25,6–34,1 (2,6) cm.
As one of the most important pieces of furniture, the desk height should be appropriate for children to feel comfortable while working on it. Field measurements show that the desk height is 76,0 cm. The definition of the 95th percent of the desk height is taken according to the recommendations of Rosyidi et al. [36]. Figure 8 shows that the height of the desk exceeds all the heights of the measurements, consequently there is no pupil who has body dimensions that fit the current dimensions of the school desks (Table 8, Fig. 9).
Mismatch percentage for table height according to grades I–V.
Comparison of stature according to data for countries: Kosovo, The Netherlands, Chile.
Comparisons of average stature between children of the same ages in Chile, Belgium and Kosovo (F-Female; M-Male)
Recommendations for student desk heights are: for the first grades 56,5–66,9 (3,2) cm, for the second grades 58,5–67,7 (3,0) cm, for the third grades 61,2–68,2 (2,9) cm, for the fourth grades 64,0–69,4 (3,0) cm, for the fifth grades 67,4–71,2 (3,3) cm.
The main purpose of this study is to analyze the discrepancy between anthropometric dimensions of children and dimensions of school furniture in the Republic of Kosovo.
The data in this research show results obtained from 720 children of grades 1–5 (ages 6–11 years). Although the study included 144 children for each grade, the good sample distribution (divided into the 4 largest regions of the country) allows us to consider that the paper represents an inclusiveness and that it can be a good indicator and can be regarded as a general study for all countries.
The results speak of a noticeable discrepancy between the anthropometric dimensions of the children and the dimensions of the furniture (chair and table) in which they sit during their classes. High mismatching was found in the height and depth of the chair and in the height of the work desk, which are considered critical dimensions when sitting on them. Also, significant discrepancies were found in the width of the chair and at the height of the chair backrest.
The use of poorly designed school furniture increases the possibility of pupils’ health problems. Moreover, this phenomenon affects pupils of young ages more.
Based on anthropometric measurements made of pupils, new dimensions have been recommended that primary schools in Kosovo should use. Based on data from other researchers who point out the importance of matching school furniture dimensions to children’s body size and given the other design requirements and financial limitations for 1058 (Ministry of Education, Science, Technology and Innovation, Statistical Notes 2020/21; https://masht.rks-gov.net/statistikat) primary schools of Kosovo, we consider that where it is possible, these data should be considered to improve school facilities continuously.
Future research
The results presented in this paper are a good starting point to continue with further research in the future. The impact of furniture discrepancy in children’s health problems in primary schools and the role of ergonomic furniture in improving the quality of learning in primary schools would be of particular interest to society in general. Also, it would be interesting to review the standard SK EN 1729-1:2015 / AC: 2019, which defines the dimensions of school furniture for primary school students in Kosovo and harmonize it with the research findings.
Conflict of interest
None to report.
Ethical approval
Ethical approval was obtained from the University of Applied Sciences in Ferizaj Ethics Commission (no. 1992/22/UASF, date 6/6/2022).
Informed consent
Not applicable.
Footnotes
Acknowledgments
The authors are thankful for the support received from the University of Applied Sciences in Ferizaj.
Funding
Not applicable.