School bags and associated back pain

Abstract

Introduction: The most common health problem associated with the negative effect of heavy school bags is back pain, and non-specific back pain is frequently observed in childhood. The prevalence of back pain in schoolchildren varies from 12% to 92%, depending on the age and affected region of the back. To prevent the occurrence of back pain in schoolchildren, the weight of school bag should not exceed 10% of the child’s body mass.
Methods: This was a descriptive, cross-sectional study conducted in April 2017. We included 79 students of the fifth and sixth grade from the elementary school in Sarajevo. Information on the weight and type of school bag, method of carrying a school bag, and feelings of pain and tiredness due to school bag were obtained by questionnaire.
Results: In the total sample, the majority of the students (64.6%) reported occasional back pain while carrying the bag, 20.3% of students reported no back pain, and 11.4% of students experienced frequent back pain. The mean school bag weight in the fifth grade was 4.01 ± 0.57 kg, and it was significantly higher (4.61 ± 0.86 kg) in the sixth grade. About 48.5% of the students in the fifth and 50% in the sixth grade carried school bags weighing more than 10% of the body mass. A higher mean weight of school bag was significantly more frequent in students who reported always feeling tired (11.03 ± 2.74%) compared to those who did not feel tired while carrying the school bag (8.41 ± 2%).
Conclusions: Overall, more frequent occurrence of back pain and tiredness in schoolchildren was associated with heavier school bags (>10% of the body mass), and the occurrence of back pain due to school bag was related to gender (i.e., back pain was more common in girls compared to boys).

Full text

Journal of Health Sciences XXXX;X(X):1-10 http://www.jhsci.ba
Journal of Health Sciences
RESEARCH ARTICLE Open Access
Schoolbags and associated back pain
Amra Mačak Hadžiomerović¹*, Amila Jaganjac¹, Dijana Avdić¹, Emira Švraka¹, Arzija Pašalić¹,
Eldad Kaljić¹, Danijela Domljan2, Edita Omerović¹
¹Faculty of Health Studies, University of Sarajevo, Bolnička 25, 71000 Sarajevo, Bosnia and Herzegovina,
2Faculty of Forestry, University of Zagreb, Svetosimunska 25, 10000 Zagreb, Croatia
ABSTRACT
Introduction: The most common health problem associated with the negative effect of heavy schoolbags
is back pain, and non-specific back pain is frequently observed in childhood. The prevalence of back pain
in schoolchildren varies from 12% to 92%, depending on the age and affected region of the back. To
prevent the occurrence of back pain in schoolchildren, the weight of schoolbag should not exceed 10%
of the child’s body mass.
Methods: This was a descriptive, cross-sectional study conducted in April 2017. We included 79 students
of the fifth and sixth grade from the elementary school in Sarajevo. Information on the weight and type
of schoolbag, method of carrying a schoolbag, and feelings of pain and tiredness due to schoolbag were
obtained by questionnaire.
Results: In the total sample, the majority of the students (64.6%) reported occasional back pain while
carrying the bag, 20.3% of students reported no back pain, and 11.4% of students experienced frequent
back pain. The mean schoolbag weight in the fifth grade was 4.01 ± 0.57 kg, and it was significantly
higher (4.61 ± 0.86 kg) in the sixth grade. About 48.5% of the students in the fifth and 50% in the
sixth grade carried schoolbags weighing more than 10% of the body mass. A higher mean weight of
schoolbag was significantly more frequent in students who reported always feeling tired (11.03 ± 2.74%)
compared to those who did not feel tired while carrying the schoolbag (8.41 ± 2%).
Conclusions: Overall, more frequent occurrence of back pain and tiredness in schoolchildren was associ-
ated with heavier schoolbags (>10% of the body mass), and the occurrence of back pain due to school-
bag was related to gender (i.e., back pain was more common in girls compared to boys).
Key words: Schoolbag weight; back pain; tiredness
INTRODUCTION
Non-specic back pain is a common symptom in
childhood, and it may occur more frequently in
some cases. Considering the potential eect of recur-
rent non-specic back pain, which is experienced
by children and adolescents during their everyday
activities at home and school, health professionals,
teachers as well as parents and guardians should pay
close attention to this issue (1,2).
Pain associated with musculoskeletal disorders is a
condition caused by the load of the musculoskeletal
system over a longer period. is load does not only
aect the tendons and muscles but also the cervical
*Corresponding author: Amra Mačak Hadžiomerović, Faculty
of Health Studies, University of Sarajevo, Bolnička 25, 71000
Sarajevo, Bosnia and Herzegovina.
E-mail: amramacak@yahoo.com
Submitted: 25 February 2018/Accepted: 30 March 2018
DOI: https://doi.org/10.17532/jhsci.2017.510
© 2018 Amra Mačak Hadžiomerović,
et al.
licensee University of Sarajevo - Faculty of Health
Studies. This is an Open Access article distributed under the terms of the Creative Commons
Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted
use, distribution, and reproduction in any medium, provided the original work is properly
cited.
81,9(56,7<2)6$5$-(92
)$&8/7<2)+($/7+678',(6

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nerves and joints, upper and lower back, thorax,
shoulders, arms, and hands. According to epidemio-
logical studies on non-specic back pain in children
and adolescents, the prevalence rate increases with the
age of respondents, ranging between 12% and 92%.
Some studies showed a higher prevalence of back
pain in girls compared to boys, while other studies
reported that boys are at greater risk to develop back
pain or they found no statistically signicant gen-
der dierence in the prevalence of back pain (3-6).
According to the National Health and Nutrition
Examination Survey Series II, non-specic back
pain occurs before the age of 20 in approximately
11% of the general population (7).
Although certain types of behavior and sociode-
mographic factors are assumed to aect the onset
of musculoskeletal changes and back pain, the most
important causative factors remain unclear (2).
Factors that are commonly associated with non-spe-
cic back pain in schoolchildren are: Age and gender,
schoolbags (heavy schoolbags, method of schoolbag
carrying, and improperly packed schoolbags), poor
lifestyle habits (watching TV for long hours, exces-
sive computer use, and playing video games), poor
posture while sitting for long periods, furniture that
does not t the body proportions of a child, lack of
physical activity, obesity, etc. (2,5,6,8).
Schoolbags are the most common means of carry-
ing books and school supplies among schoolchil-
dren (9). e problem of heavy schoolbags is a
global problem, and a number of studies addressed
this problem in dierent countries. e most com-
mon health problem related to heavy schoolbags is
back pain. Other consequences of heavy schoolbags
include bad posture, fatigue, exhaustion, and con-
sequently concentration problems and poor school
performance (10,11). Moreover, heavy schoolbags
can aect the bone growth, cause stress injuries,
and shift the center of gravity of a body in the same
direction as the load (12).
According to the World Health Organization rec-
ommendations, the weight of schoolbags should not
exceed 10% of child body mass (13). Schoolbags
with a load exceeding 10% of the body mass increase
energy consumption, increase the neck and trunk for-
ward lean, and result in decreased pulmonary volume
and increased cardiorespiratory parameters (14).
If a schoolbag is worn incorrectly, it may cause strain
or injury to the back and abdominal muscles. To pre-
vent this, the shoulder straps of schoolbag should be
adjusted, as well as the hip belt if it is present, thus
ensuring that the load to the lower back is reduced
(15). When a schoolbag is well designed and posi-
tioned properly to the back and abdominal muscles,
which are among the strongest muscles in the body,
they can support the weight of schoolbag. In this way,
the load is evenly distributed over the body, reducing
the risk of back pain and musculoskeletal disorders
(11). e proper method of carrying a schoolbag
and the recommended weight are based on the body
mass index (BMI) and age of the child (16).
Assessing non-specic back pain at school age may
provide a closer insight into the possible develop-
ment of related disorders in adulthood. To avoid
the adverse eects of back pain, early prevention is
required (17,18). Early childhood and adolescence is
the period when a child develops basic healthy hab-
its and related behavioral characteristics. erefore,
a child should be able to develop its physical abilities
from an early age, to acquire new skills and knowl-
edge, and most importantly, to learn how to take
care of the body (19).
Our aim was to investigate the prevalence of back
pain in fth- and sixth-grade students of the ele-
mentary school as well as to analyze whether school-
bag weight and method of carrying schoolbag lead
to tiredness and back pain in children. We have also
analyzed the BMI in relation to the occurrence of
back pain in the fth-and sixth-grade students.
METHODS
Study groups
e sample consisted of the fth-and sixth-grade
students of the Elementary School Izet Šabić in
Sarajevo. Atotal of 79 students were included, of
which 39 students were enrolled in the fth grade
and 40 students in the sixth grade.
is descriptive, cross-sectional study was conducted
in April 2017. We included those students who were
present in the school at the time of investigation and
for which parental consent was obtained. e students
who were not present in the school at the time of
investigation as well as students diagnosed with mus-
culoskeletal conditions were excluded from the study.

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e study was approved by the Ministry of
Education, Science and Youth of Sarajevo Canton
and the management of the elementary school.
Research instruments
Measurement of schoolbag weight
We measured schoolbag weight for ve consecutive
days during a work week (Monday to Friday), using
the transtheoretical model scale, model M 130. e
ratio of mean schoolbag weight to body weight was
determined for each student and used to calculate
the percentage weight of schoolbag in relation to the
body weight.
Measurement of the BMI
We measured the BMI in the fth-and sixth-grade
students of the Elementary School Izet Šabić in
Sarajevo. e BMI is an anthropometric measure of
body composition (fat) in relation to age and gender
and is calculated by dividing body mass in kilograms
by the square of the height in meters (BMI = kg/m2).
e BMI is used as an indicator of malnutrition,
obesity, and risk of developing obesity in children
and adolescents (20).
e questionnaire for assessing schoolbag type,
method of carrying schoolbag, items included in
the bag, and subjective perception of the school-
bag load, described in the study of Kellis and
Emmanouilidou(21), was adapted and used in this
study, with permission of the authors: e ques-
tionnaire included questions related to the age and
gender of students, weight, and type of schoolbag,
method of carrying schoolbag, sport activities, dis-
tance from school to home, as well as means of com-
muting to school (21).
Statistical analysis
e database including all survey data was created
using Microsoft Excel 2013. After data integrity
was conrmed, statistical analysis was performed
using IBM SPSS Statistics for Windows, Version
20.0 (IBM Corp., Armonk, NY). Data were pre-
sented using dierent measures of descriptive sta-
tistics, including arithmetic mean, standard devi-
ation, median, interquartile range [the 25th and
75thpercentile], absolute frequency (N), and relative
frequency (%).
Normal distribution of continuous variables was
assessed graphically (histogram and quantile plot)
and by the Kolmogorov–Smirnov test. Categorical
variables were analyzed using Pearson’s Chi-squared
test or Fisher’s exact test. Data with normal distri-
bution were compared using analysis of variance
(ANOVA) and Dunnett’s test, while data without
normal distribution were analyzed using ANOVA
with a Bonferroni correction. e results are pre-
sented in the forms of tables (with 3 decimal places)
or graphs. e level of signicance was set at p < 0.05.
RESULTS
e study included 79 students enrolled in the
Elementary School Izet Šabić in Sarajevo, who met
the inclusion criteria. Out of the total number, 39
students attended the fth grade and 40 attended
the sixth grade. ere were 45.6% boys and 54.4%
girls in the total sample. In the fth grade, there
were 46.2% males and 53.8% females, and similar
distribution was observed in the sixth grade (45%
males and 55% females). No signicant dierence
was observed in the gender distribution between the
grades (χ2 = 0.010; p = 0.549; Table1).
e mean age in the total sample was
11.04 ± 0.85years. In the fth grade, the mean age
TABLE 1. Gender distribution in fth‑ and sixth‑grade
elementary school students
Grade
n
(%) Total
n
(%)
Fifth Sixth
Gender
Males 18 (46.p2) 18 (45.0) 36 (45.6)
Females 21 (53.8) 22 (55.0) 43 (54.4)
Total 39 (100.0) 40 (100.0) 79 (100.0)
χ
2=0.010; p=0.549
TABLE 2. Age distribution in fth‑ and sixth‑grade elementary
school students
Grade N X SD SEM Minimum Maximum
Fifth
grade
39 10.31 0.46 0.07 10 11
Sixth
grade
40 11.75 0.43 0.06 11 12
Total 79 11.04 0.85 0.09 10 12
F=200.095; p=0.001; SD: Standard deviation; SEM: Standard
error of the mean

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was 10.31 ± 0.46years, while in the sixth grade, it
was 11.75 ± 0.43years (Table 2). We observed no
statistically signicant dierence in the BMI between
the students of the fth and sixth grade (χ2 = 0.574;
p = 0.449). e BMI <18kg/m2 (indicating malnutri-
tion) had 54.1% of the students in the fth grade and
42.1% of the students in the sixth grade. e BMI
19–25 kg/m2 (normal weight) had 43.2% of fth-
grade students and 57.9% of sixth-grade students. In
the overweight category (BMI 26-30 kg/m2), there
was only one student from the fth grade and no stu-
dent from the sixth grade (Figure1).
e mean schoolbag weight in the fth grade was
4.01 ± 0.57kg, while it was 4.61 ± 0.86kg in the
sixth grade, with a signicant dierence between
the two groups (F = 12.931; p = 0.001). Asigni-
cant dierence in schoolbag weight between the two
groups was also observed in relation to the work-
ing days of the week, except for Friday (F = 2.224;
p = 0.140).
On Monday, the mean schoolbag weight in the
fth grade was 4.39 ± 0.94kg, and it was 4.93 ±
0.70kg in the sixth grade (F = 8.237; p = 0.005).
On Tuesday, the mean schoolbag weight was 4.21 ±
0.81kg in the fth grade vs. 4.95 ± 1.12kg in the
sixth grade (F = 11.168; p = 0.001); on Wednesday,
75 ± 0.93kg in the fth grade versus 4.41 ± 1.39kg
in the sixth grade (F = 6.005; p = 0.017); and on
ursday, 3.97 ± 0.93 kg in the fth grade ver-
sus 4.64 ± 1.25kg in the sixth grade (F = 7.196;
p = 0.009) (Table3).
We also observed a signicant dierence in the
method of carrying schoolbag between the fth-and
sixth-grade students (χ2 = 6.344; p = 0.002). Among
the students in the fth grade, 94.9% carried the
bag on the shoulders, 2.6% on one shoulder and
2.6% across the body. In the sixth grade group,
62.5% students carried the bag on the shoulders,
30% on one shoulder, and 7.5% on the side of the
body. No student in the sixth grade carried the bag
across the body (Figure2).
Overall, most students (50.6%) reported sometimes
feeling tiredness while carrying the schoolbag. is
feeling was reported by 64.1% of fth-grade students
and 37.5% of sixth-grade students, with no signi-
cant dierence between the two groups (χ2 = 3.001;
p = 0.083). Frequent, schoolbag-related tiredness
was reported by 25.6% of students in the fth and
32.5% of students in the sixth grade. Among the
fth-grade students, 5.1% reported that they never
felt tired while carrying the schoolbag, and the same
percentage of students was always tired. In the sixth-
grade group, 10% of students never felt tired and
20% always felt tired while carrying the schoolbag
(Table4).
In the total sample, the majority of the participants
(64.6%) reported occasional back pain while carrying
the bag in the last 4weeks, and no signicant dier-
ence was observed between the two groups (χ2 = 0.671;
p = 0.413). In the fth grade, 23.1% of students and in
the sixth grade17.5% of students reported no school-
bag-related back pain. Frequent schoolbag-related
FIGURE 1. Groups of fth‑ and sixth‑grade elementary school students according to the body mass index.

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FIGURE 2. Methods of carrying schoolbag among fth‑ and sixth‑grade students of elementary school.
TABLE 3. Mean schoolbag weight (kg) in relation to workdays of the week
Day of week NX (kg) SD SEM Minimum Maximum
Monday
Fifth 39 4.39 0.94 0.15 2.50 6.25
Sixth 40 4.93 0.70 0.11 3.50 6.50
F=8.237; p=0.005
Tuesday
Fifth 39 4.21 0.81 w0.13 2.50 6.75
Sixth 40 4.95 1,12 0.17 3.00 7.00
F=11.168; p=0.001
Wednesday
Fifth 39 3.75 0.93 0.14 1.75 6.50
Sixth 40 4.41 1,39 0.22 2.25 7.50
F=6.005; p=0.017
Thursday
Fifth 39 3.97 0.93 0.14 2.25 6.25
Sixth 40 4.64 1,25 0.19 2.50 7.00
F=7.196; p=0.009
Friday
Fifth 39 3.73 0.98 0.15 2.00 5.75
Sixth 40 4.09 1,13 0.18 2.00 6.00
F=2.224; p=0.140
Total
Fifth 39 4.01 0.57 0.09 2.79 5.70
Sixth 40 4.61 0.86 0.13 2.90 6.04
F=12.931; p=0.001
SD: Standard deviation; SEM: Standard error of the mean

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back pain was experienced by 10.3% of fth grade
and 12.5% of sixth-grade students (Table5).
e mean schoolbag weight/body mass ratio was
9.94 ± 2.70% (4.8–16.3%) in the overall sample,
with no signicant dierence in the ratio between
the two groups (9.67 ± 2.72% in the fth and 10.21
± 2.68% in the sixth grade; F = 0.765; p = 0.384).
While there was no signicant dierence in the body
mass of students between the fth-and sixth-grade
groups (p = 0.304), there was a signicant dierence
in schoolbag weight (p = 0.001), i.e.,the weight of
schoolbag was higher in sixth grade (Table6).
e students from the fth and sixth grade were
compared in relation to schoolbag weight according
TABLE 4. Feeling of tiredness related to schoolbag
Grade n (%) Total n (%)
Fifth Sixth
Feeling of schoolbag‑related tiredness
Never 2 (5.1) 4 (10.0) 6 (7.6)
Sometimes 25 (64.1) 15 (37.5) 40 (50.6)
Often 10 (25.6) 13 (32.5) 23 (29.1)
Always 2 (5.1) 8 (20.0) 10 (12.7)
Total 39 (100.0) 40 (100.0) 79 (100.0)
χ
2=3.001; p=0.083
TABLE 5. Occurrence of schoolbag ‑related back pain in the last 4 weeks
Grade n (%) Total n (%)
Fifth Sixth
Occurrence of back pain due to schoolbag
Never 9 (23.1) 7 (17.5) 16 (20.3)
Sometimes 25 (64.1) 26 (65.0) 51 (64.6)
Often 4 (10.3) 5 (12.5) 9 (11.4)
Always 1 (2.6) 2 (5.0) 3 (3.8)
Total 39 (100.0) 40 (100.0) 79 (100.0)
χ
2 =0.671; p=0.413
TABLE 6. Schoolbag weight (absolute and relative) in relation to the body mass of students
Parameters N X SD SEM Minimum Maximum
Schoolbag weight (kg)
Fifth grade 39 4.01 0.57 0.09 2.79 5.70
Sixth grade 40 4.61 0.86 0.13 2.90 6.04
Total 79 4.32 0.73 0.11 2.90 6.04
F=12.931; p=0.001
Child body mass (kg)
Fifth grade 39 44.36 11.62 1.86 29 80
Sixth grade 40 46.73 8.49 1.34 31 66
Total 79 45.56 10.16 1.14 29 80
F=1.071; p=0.304
Schoolbag weight (%)
Fifth grade 39 9.67 2.72 0.43 4.80 16.30
Sixth grade 40 10.21 2.68 0.42 5.80 15.80
Total 79 9.94 2.70 0.30 4.80 16.30
F=0.765; p=0.384. SD: Standard deviation; SEM: Standard error of the mean

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Amra Mačak Hadžiomerović et al. Journal of Health Sciences XXXX;X(X):1-10 http://www.jhsci.ba
to the body mass, i.e.,≤10% or >10% of the body
mass of the student. ere was no signicant dif-
ference between the fth-and sixth-grade students
(p = 0.546) with regard to the schoolbag weight
(%), and in both groups, about half of the students
(48.5% in the fth grade and 50% in the sixth
grade) carried heavier schoolbags (>10% of body
mass) (Figure3).
A higher mean weight of schoolbag (%) was signi-
cantly more frequent in students who reported always
feeling tired (11.03 ± 2.74%) compared to those
who did not feel tired while carrying the schoolbag
(8.41 ± 2%) (p = 0.034), thus conrming the associ-
ation between the weight of schoolbag and the occur-
rence of tiredness in children of school age (Table7).
Similarly, back pain was more common in students
with a higher mean weight of schoolbag (%)
compared to those with lower schoolbag weight
(p = 0.042). e mean schoolbag weight was
10.90 ± 3.81% in students who reported persistent
back pain while carrying the bag (Table8).
ere was also a signicant dierence in the occur-
rence of back pain in relation to gender, where back
pain was more frequent in female compared to male
students (p = 0.005). In our study group, the BMI
was not associated with the occurrence of back pain
while carrying schoolbag (p = 0.457) (Table9). e
type of schoolbag and method of carrying schoolbag
were also not associated with the occurrence of back
pain in our group (p > 0.05) (Table10).
DISCUSSION
Our study group comprised 45.6% boys (46.2%
males in the fth grade and 45% in the sixth) and
54.4% girls (53.8% females in the fth grade and
55% in the sixth). e average age in the total sam-
ple was 11.04 ± 0.85years.
e BMI <18kg/m2 had 54.1% of the students in
the fth grade and 42.1% in the sixth grade. e
BMI 19–25kg/m2 had 43.2% of the fth-grade stu-
dents and 57.9% of the sixth-grade students. Only
one student from the fth grade had BMI 26–30kg/
m2, and no student from the sixth grade was in that
FIGURE 3. The percentage of students in each grade in relation
to the weight of schoolbag (%), i.e., ≤10% or >10% of the body
mass.
TABLE 7. Schoolbag weight (%) in relation to feeling of tiredness
Schoolbag‑related feeling of tiredness N X (%) SD SEM Minimum Maximum
Never 6 8.41 2.00 0.82 4.80 10.50
Sometimes 40 10.06 2.78 0.44 5.80 16.30
Often 23 9.67 2.62 0.54 6.40 15.80
Always 10 11.03 2.74 0.86 7.90 15.70
Total 79 9.94 2.70 0.30 4.80 16.30
F=8.142; p=0.034. SD: Standard deviation; SEM: Standard error of the mean
TABLE 8. Schoolbag weight (%) in relation to back pain
Schoolbag‑related back pain N X (%) SD SEM Minimum Maximum
Never 16 9.66 2.66 0.66 4.80 14.30
Sometimes 51 9.95 2.75 0.38 5.80 16.30
Often 9 10.07 2.53 0.84 7.70 15.80
Always 3 10.90 3.81 2.20 6.50 13.20
Total 79 9.94 2.70 0.30 4.80 16.30
F=7.041; p=0.042. SD: Standard deviation; SEM: Standard error of the mean

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category. ere was no statistically signicant dier-
ence in the BMI between the students of the fth
and sixth grade.
Zaidi et al. (22) investigated association of musculo-
skeletal pain with heavy bag packs in schoolchildren.
In their group consisting of 56% girls and 44%
boys of average age of 12years, 48% of students had
BMI lower than normal (BMI <18kg/m²) indicat-
ing malnutrition in those children, 52% had nor-
mal BMI, between 19kg/m² and 25kg/m², and no
student was overweight (BMI 26–30kg/m²) (22).
ese results are in agreement with ours.
In our group, the mean schoolbag weight in the
fth grade was 4.01 ± 0.57kg, and it was signi-
cantly higher (4.61 ± 0.86 kg) in the sixth grade
(F = 12.931; p = 0.001). Asignicant dierence in
schoolbag weight between the fth-and sixth-grade
students was also observed in relation to the work-
ing days of the week, except for Friday (F = 2.224;
p = 0.140).
Paušić et al. investigated the eects of schoolbag
weight on back pain in students from the rst to
fourth grade of elementary school. ey showed that
a higher weight of schoolbag was signicantly asso-
ciated with higher grades, i.e.,in the rst grade, the
mean schoolbag weight was 4.92kg, in the second
5kg, in the third 4.54kg, and in the fourth, it was
5.28 kg (23). Considering that Paušić et al. (23)
used a similar methodology as in our study, we can
conclude that the results of the two studies are in
agreement.
Moreover, in the study of Kellis and Emmanouilidou
(21), which provided the questionnaire used in
our study, the mean schoolbag weight was 5.30 ±
1.25kg, in 703 boys and girls from Greece, aged
6 to 14years. ey also showed that the weight of
schoolbag was signicantly higher in groups with
older students compared to groups with younger
students (21).
Most of our students carried the bag on both shoul-
ders, i.e., 94.9% students in the fth grade and
62.5% in the sixth grade. In the study of Paušić
et al. (23), 93.1% of the students wore the bag on
both shoulders. Similar results were reported by two
other studies that investigated back pain in school-
children (24,25). On the other hand, El-Nagar and
Mady reported that the majority of students who
felt back pain in their study carried the schoolbag
on one shoulder or in one hand (6), which is not in
agreement with our results.
TABLE 9. Gender and BMI in relation to back pain
Parameters Occurrence of schoolbag‑related back pain in the last 4 weeks p
Never Sometimes Often Always
Gender (%)
Male 11 (68.8) 24 (47.1) 0 (0.0) 1 (33.3) 0.005
Female 5 (31.3) 27 (52.9) 9 (100.0) 2 (66.7)
BMI (kg/m2) 19.79±4.32 18.43±3.07 19.77±3.40 18.84±3.41 0.457
BMI: Body mass index
TABLE 10. Type of schoolbag and method of schoolbag carrying in relation to back pain
Parameters Occurrence of schoolbag‑related back pain in the last 4 weeks (%) p
Never Sometimes Often Always
Type of schoolbag
Backpack 16 (21.3) 48 (64.9) 7 (9.5) 3 (4.1) 0.166
Single‑trap bag 0 (0.0) 3 (60.0) 2 (40.0) 0 (0.0)
Method of carrying schoolbag
On both shoulders 12 (19.4) 39 (62.9) 8 (12.9) 3 (4.8) 0.384
On one shoulder 3 (23.1) 9 (69.2) 1 (7.7) 0 (0.0)
Across the body 1 (100.0) 0 (0.0) 0 (0.0) 0 (0.0)
On one side of the body 0 (0.0) 3 (100.0) 0 (0.0) 0 (0.0)

9
Amra Mačak Hadžiomerović et al. Journal of Health Sciences XXXX;X(X):1-10 http://www.jhsci.ba
Most of the students from both of our groups
(50.6%) reported that they sometimes felt tiredness
while carrying the schoolbag (64.1% of fth-grade
students and 37.5% of sixth-grade students), with
no signicant dierence between the two groups.
Frequent tiredness was reported by 29.1% of stu-
dents in the total sample (25.6% in the fth and
32.5% in the sixth grade). Similar results were
reported by Kellis and Emmanouilidou (21),
i.e.,most of their participants (28.2%) felt tiredness
often or sometimes, while carrying the schoolbag.
e majority of the students in our group (64.6%)
reported occasional back pain while carrying the
bag in the last 4weeks (64.1% in the fth grade
and 65.0% in the sixth grade). In the total sample,
20.3% of students reported no back pain (23.1%
of fth-grade students and 17.5% of sixth-grade
students). Frequent back pain was experienced by
11.4% of students (10.3% of fth grade and 12.5%
of sixth-grade students). In a cross-sectional study
on 586 Iranian schoolchildren aged 12–14 years,
Dianat et al. (26) showed that the students of higher
grades reported feeling of pain while carrying the
schoolbag signicantly more frequently than the
lower grades students (26). eir results correlated
with ours to some extent.
In our study, the mean schoolbag weight/body mass
ratio was 9.94 ± 2.70% (4.8-16.3%) in the over-
all sample, with no signicant dierence in the
ratio between the fth- and sixth-grade groups.
Furthermore, there was no signicant dierence in
the body mass of students between the fth-and
sixth-grade groups, but schoolbag weight was sig-
nicantly higher in the sixth-grade group. is
may be explained by the fact that schoolbag weight
depends on class schedule, where students of higher
grades usually have more school subjects and con-
sequently more books and other school items to
carry. In general, the weight of schoolbag should not
exceed 10% of the child body mass (13).
We observed no signicant dierence between the
fth- and sixth-grade students in relation to the
schoolbag weight (≤10% or >10% of child body
mass), and in both groups, about half of the stu-
dents (48.5% in the fth and 50% in the sixth
grade) carried schoolbags weighing more than
10% of the body mass. Two other studies on the
association between schoolbag weight and back
pain in children showed that majority of students
carried heavier schoolbags (>10% of the body
mass) (27,28). Overall, these results indicate that
schoolchildren are often required to carry school-
bags that are heavier than recommended.
A higher mean weight of schoolbag (%) was signi-
cantly more frequent in students who reported feel-
ing tired constantly compared to those who did not
feel tired while carrying the schoolbag, conrming
the relationship between the weight of schoolbag
and the occurrence of tiredness in schoolchildren.
is is probably because the body tries to compen-
sate for the load on the spine caused by a heavy
schoolbag, leading to higher levels of tiredness.
Consistently, back pain was more common
in our students with a higher mean weight of
schoolbag (%) compared to those with lower bag
weight. e mean schoolbag weight was 10.90 ±
3.81% in the students who reported persistent back
pain. In agreement with our ndings are the results
of Adeyemi et al. (28) who also demonstrated the
signicant eect of heavy schoolbag on the degree
of feeling back pain in 615 schoolchildren aged
between 7 and 12years.
In our group, the occurrence of back pain was related
to the gender, and back pain was more frequent in
female compared to male students. Comparably
to our results, Aprile et al. (29) demonstrated, in
a group of 5318 healthy students aged 6-19years,
that schoolbag-related pain was signicantly
more frequent and more severe in girls compared
to boys (29).
CONCLUSION
Almost two-thirds (64.6%) of fth-and sixth-grade
schoolchildren experience occasional back pain due
to the weight of the schoolbag, while 11.4% experi-
ence frequent back pain. Half of the schoolchildren
carry the schoolbags weighing more than 10% of the
student’s own weight and heavy schoolbags are more
frequently associated with tiredness and back pain.
Back pain associated with weight of the schoolbag
occurs more frequently in female students. No asso-
ciation was observed between the method of carry-
ing the schoolbag and back pain.

10
http://www.jhsci.ba Amra Mačak Hadžiomerović et al. Journal of Health Sciences 2018;X(X):1-10
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