Medical
Communication
Biosci. Biotech. Res. Comm. 11(3): 402-408 (2018)
Effect of school bags on body mechanics among
Saudi children
Fayz S Al Shahry,
1
Hind Abdulrahman Almahmoud
2
, Razan IbrahimAlhujairy
2
and Khalood
Khalid Aljohi
2
1
Assistant Prof. CAMS, KSAU-HS, Consultant Neurorehabilitation Service, King Abdulaziz Medical City, Riyadh
2
Student, Occupational Therapy, CAMS, KSAU-HS, Riyadh Saudi Arabia
ABSTRACT
It is well known that school bag has effects on the posture of early school students. Therefore, lack of data about
the impact of school bags on body mechanics of children from Saudi Arabia.This study aimed to assess the effect of
heavy school bag on the student’s body mechanics at elementary school in Riyadh. We conducted this observational
cross-sectional study by observing the posture, palpation meter (PALM), interview, and examining school bag con-
tent, of primary school students across the Riyadh. Total of 200 students was included in our study. Less than half
of the students reported pain (41.5%). Students who reported pain (n=83) most of them had inappropriate school bag
weight (85.5%), whereas (14.5%) school bag weight was appropriate and (67%) students had tilted in the shoulders.
Our nding suggested that heavy school bags contributed to the presence of pain and shoulder tilt, whereas long
duration of carrying school bag did not affect shoulder tilt. Thus, in future, education for parents must be conducted
to make sure to prevent students from carrying bags exceeding the acceptable standard limit.
KEY WORDS: SCHOOL BAG, ELEMENTARY SCHOOL, POSTURE, PAIN
402
ARTICLE INFORMATION:
*Corresponding Author: shahryf@hotmail.com
Received 17
th
Aug, 2018
Accepted after revision 29
th
Sep, 2018
BBRC Print ISSN: 0974-6455
Online ISSN: 2321-4007 CODEN: USA BBRCBA
Thomson Reuters ISI ESC / Clarivate Analytics USA and
Crossref Indexed Journal
NAAS Journal Score 2018: 4.31 SJIF 2017: 4.196
© A Society of Science and Nature Publication, Bhopal India
2018. All rights reserved.
Online Contents Available at: http//www.bbrc.in/
DOI: 10.21786/bbrc/11.3/8
INTRODUCTION
It is well known that schoolbag has effects on the pos-
ture of early school students. Studies have revealed that
the prevalence of musculoskeletal issues in school chil-
dren due to heavy school bags is increasing; therefore, it
has become a concern, (Chow etal. 2010, Shamsoddini,
et al. 2010).
Earlier studies have shown that carrying
heavy school bags has harmful effects on the children’s
musculoskeletal systems such as increasing in postural
sway, and trunk muscle activity levels, Dianat et al.
2013). Students cannot carry heavy loads due to their
Fayz S Al Shahry etal.
size and weight. Thus, carrying heavy school bags leads
to schoolbag-related injuries for children, Watson etal.,
(2003). According to doctors and physical therapists, the
schoolbag weight should not exceed 10-15% of the stu-
dents’ body weight to avoid musculoskeletal problems,
Several workers ( Murphy etal.2007, Dockrell etal. 2013,
Al-Saleem etal. 2016 and Dowshen, 2017) have found
the prevalence of back pain among school students by
evaluating the school bags weight about their weight.
Out of 2567 school students, 1860 (72.46%) were carry-
ing schoolbags more than the acceptable standard. The
results have shown that female student’s school bags
are more substantial than male student school bags, and
42% of the school students reported back pain.
Body mechanics education depends on the researcher
that assesses the effects of mechanical loading or stress
on controlling and supporting the spine. The mechanism
of loading could be compression, torque, bending, shear,
and tension or a summation of these forces to perform
functional tasks from the dynamic nature, Lieber etal.
(2000).
Excessive forces working on the spine can cause
a dynamic deformation of the spine structure the human
body can reduce pain stimulation by lowering mechani-
cal stress thus contribute to pain management Lieber
et al.2000
.
The majority of the studies focused on the
schoolbag weight as the most important factor affecting
the musculoskeletal system, while there are also other
factors such as duration and method of carrying school-
bags affecting the musculoskeletal system, (Dianat etal.
2013, Dockrell etal. (2015) and Patil etal. 2016).
Carrying the school bag over one shoulder makes
the student lean to one side due to the extra weight
which harms the student by causing back pain, shoulder
and neck strain. If the school bag is placed in a wrong
way over the shoulders, it could lead to back, shoul-
der and neck pain because the student tries to resist the
weight’s force that pulls backward by bending forward
which causes compression to the spine. Also, carrying
school bag incorrectly causes bad posture Pascoe etal.
(1997). Dianat etal. (2014) reported that musculoskel-
etal symptoms prevalent for 307 primary school students
were caused by school bags. Results have shown that
the shoulders were most affected body region among
the sample with (70%), then wrists/hands (18.5%), upper
back (13.6%) and low back (8.7%), while no symptoms
were noted for the lower limbs, (Dianat etal. 2013) .
The basic assumption based on the biomedical model
is that the maturing spine cannot handle the mechanical
load of the backpack suf ciently Reneman etal. (2006).
A previous study has shown that head, cervical spine
and shoulder alterations in posture throughout gait ter-
minations in student due to load carriage. Carrying more
than the standard limit for schoolbag weight has effects
on the posture of the head, cervical spine, and shoulder
throughout gait terminations. The posture of the head
became more forward, while it affected the shoulder to
be more rounded and tilted Reneman etal. 2014, Mwaka
etal. (2014). Center of gravity has a signi cant effect on
schoolbag weight and in consideration of proper carry-
ing techniques. Different carrying bag techniques is one
of the signi cant factor on posture and gait of students
aged between 11 ± 13 years old, there is no difference in
the lateral spinal deviation between two-strap backpack
and students without the bag, Nevertheless, two-strap
school bag reduced carrying stress on the student back,
neck and shoulders, (Pascoe et al.1997, Skoffer et al.
2007, Mwaka etal. 2014). Moreover con rmed the mus-
culoskeletal pain as result of the heavy backpack.
The literature has demonstrated the detrimental effects
of carrying heavy school bags on school students. Stud-
ies have revealed that the prevalence of musculoskeletal
issues in school students due to heavy school bags is
increasing. There was a lack of data about the effect
of school bags on body mechanics of children at Saudi
Arabia. So, we this study aimed to assess the effect of
heavy school bag on the student at elementary school
body mechanics in Riyadh. In this study, we took in con-
sideration factors that contribute in heavy bags and the
duration of carrying the bag.
MATERIALS AND METHODS
This study was carried out in primary schools in Riyadh,
Saudi Arabia between Augusts to November 2017. It was
an observational cross-sectional study. The sample size
(n=200) divided equally for each gender as 100 males
and 100 females. The sample included primary school
students between 9-11 years old (third grade to fth
grade). We excluded students with congenital deformity,
history of accident, students younger than 9 years, and
older than 11 years, obese students. Multistage cluster
sampling was used, thus we divided Riyadh into regions
or clusters.
The schools were selected from eastern region, and
students were chosen randomly. The participants in each
school were waiting in a classroom and numbers were
distributed to them randomly so we called them by the
number then they came to do the assessment. One asses-
sor measured the student weight and their bag weight,
and examined student bags whether it was one/two
strap, loose/tight, width of strap, and its contents. Sec-
ond assessors were interviewed by self-designed ques-
tionnaire, and the other assessors were measured with
Palpation Meter (PALM).
The questionnaire was developed to cover the areas we
wanted to collect in this study. There were 22 questions
about demographic details, pain, duration of carrying
the school of bag, and whether they are educated about
BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS EFFECT OF SCHOOL BAGS ON BODY MECHANICS AMONG SAUDI CHILDREN 403
Fayz S Al Shahry etal.
the topic. The measurement tool that has been used in
this study is valid and reliable tool called palpation meter
(PALM) Petrone etal. (2003), Kellis etal. (2010). This tool
allows to determine skeletal asymmetry and then locate
the point of asymmetry by making measurements at var-
ious landmarks in the body. Also, we used scale to weigh
the students and their bags. Before visiting schools, we
contacted the school principal to permit the conduct of
the study. Informed consent form was sent to the parents
of the student for signed consent. All details of the study
delivered to the parents before the start of the study.
DATA ANALYSIS
The calculated data entered into Microsoft Excel. Cat-
egorical variables represented in frequencies and per-
centage. Mean and Standard Deviation used for continu-
ous variables. The data analysis used Chi-square test to
compare proportion the difference for various variables.
A statistical package was SPSS version 22 used for sta-
tistical analysis of the data. The P-value <0.05 was con-
sidered the level of signi cance. Appropriate diagrams
have also been used.
RESULTS AND DISCUSSION
A total of 200 students from 4 different schools par-
ticipated in the study. The average age was 9.58 years
and the SD was 0.711. There were (100) 50% male and
(100) 50% female. There were 110 (55%) third grade (9
years), 64 (32%) fourth grade (10 years), and 26 (16%)
fth grade (11 years). The study found that 83% of the
students had inappropriate schoolbag weight and 17%
appropriate as seen in (Fig 1).
It was found that female had more inappropriate
school bag weight (54.2%), while this was 45% for stu-
dents. The percentage of students with inappropriate
school bag weight of each age group was highest for
students with 10 years (90.6%), then 9 years (80%) and
lowest in 11 years (76.9%) see Table 1. Students who
were educated about the effects of school bag on body
mechanics were less (32.5%) than who were not edu-
cated (57.5%). All the students had backpack and car-
ried their backpacks over two shoulders and most of the
bags had wide strap (91.5%) and loose strap (67.5%),
whereas (8.5%) of their bags had thin strap and (32.5%)
tight strap. The mean weight of school bags was 4.82
±1.536 kg (Table 2). It was found that students who car-
ried books according to their daily schedule were (84%)
while (16%) did not. The majority of male students (66%)
and female students (78%) had extra bag content. Less
than half of the students reported pain (41.5%), and the
rest (58.5%) of them did not. The students who reported
pain (n=83) most of them had inappropriate school bag
weight (85.5%), whereas (14.5%) school bag weight had
appropriate school bag (Table 1).
The most area of pain reported was shoulder (70%),
then (18%) in back. and the least reported was in their
neck (12%). Among the students who reported pain, the
majority felt pain while carrying the bag (79.5%), after
carrying the bag (14.5%), and 6 % had felt it all the time
FIGURE 1. Appropriateness of Weight of school bag of subjects
(n= 200)
404 EFFECT OF SCHOOL BAGS ON BODY MECHANICS AMONG SAUDI CHILDREN BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS
Fayz S Al Shahry etal.
Table 1. School bag weight effects
Chi square P-value
Appropriate Not appropriate
When do you feel the pain? (n=83) While carrying the bag 7(58.3%) 59(83.1%) 9.224 0.010
After carrying the bag 2(16.7%) 10(14.1%)
All the time 3(25.0%) 2(2.8%)
What is the level of your pain?
(n=83)
Mild 2(16.7%) 36(50.7%) 12.813
0.002
Moderate 5(41.7%) 30(42.3%)
Severe 5(41.7%) 5(7%)
Gender
(n=200)
Female 5(20%) 46(42.2%) 4.252
0.039
Male 20(80%) 63(57.8%)
Educated about this topic before
(n=200)
Yes 13(38.2%) 52(31.3%) 0.614 0.433
No 21(61.8%) 114(68.7%)
Tilt
(n=200)
Yes 25(18.7%) 109(81.3%) 0.790
0. .374
No 9(13.6%) 57(86.4%)
Tilt side
(n=134)
Right 17(68.0%) 69(63.3%) 0.195 0.659
Left 8(32.0%) 40(36.7%)
Where do you feel pain exactly?
(n=83)
Neck 1(8.3%) 9(12.7%) 2.236 0.327
Shoulder 7(58.3%) 51(71.8%)
Back 4(33.3%) 11(15.5%)
Do you feel any pain?
(n=200)
Yes 12(14.5%) 71(85.5%) 0.650
0.420
No 22(18.8%) 95(81.2%)
Age in years
(n=200)
9 22(64.7%) 88(53.0%) 4.019 0.134
10 6(17.6%) 58(34.9%)
11 6(17.6%) 20(12.0%)
Table 2. The mean of school bag weight
N Minimum Maximum Mean Std. Deviation
Schoolbag Weight 200 2 14 4.82 1.536
Table 3. Carrying school bag during morning line * pain
Do you feel any pain?
Yes No Total
Do you carry your bag while
standing in the school morning
line?
Yes 22(26.6%) 22(18.8%) 44(22%)
No 61(73.4%) 95(81.2%) 156(78%)
Total 83(100.0%) 117(100.0%) 200(100.0%)
(6%). Also, among those students who reported pain
most of them had mild level of pain (46%), then mod-
erate pain (42%) and very few had severe pain (12%).
According to the age group, pain was highest among
student who age 11 years (n=26) 13(50%) and lowest
in 9 years (n=110) 41(37.2%). There was no signi cant
difference between the prevalence of pain between male
(49.4%) and female (50.6%). We found that carrying
the bag in morning line increase the incidence of pain
as (50%) who have answered yes to carrying it in the
morning have pain whereas (3.87 %) who have not carry
the bag in the morning line have pain see Table 3.
Students who had pain and tilt were 52 (26%), 19
(45.2%) of them were female, and 33 (80.5%) were male
see Table 4. 134 (67%) students had tilt in the shoul-
ders and 67 (33%) of them did not have any tilt. From
the students who had tilt in their shoulders 19% had
schoolbag weight appropriate while 81% had inappro-
BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS EFFECT OF SCHOOL BAGS ON BODY MECHANICS AMONG SAUDI CHILDREN 405
Fayz S Al Shahry etal.
priate bag weight (Figure 2). There was variety in the
degrees of shoulders tilt from 1 to 4 degrees. Out of the
students with shoulder tilt (n=134) the majority were
male (61.9%), whereas (38.1%) of them were female. We
investigated the link between the school bag weight and
the presence of tilt in shoulders in each gender. It was
found that out of the male with shoulder tilt (n=83) most
of them carried school bag with inappropriate weight
(75.9%), also in female (n=51) the majority of them car-
ried school bag with inappropriate school bag weight
(90.1%) see Table 1.
In this study, we investigated the school bag weight
concerning the student body weight. 83% of the stu-
dents had school bag weight exceeding the standard
limit range (10%) the highest limit according to the Ire-
land Republic, European and Health Promotion Board
of Singapore guidelines and only 17% had an appropri-
ate bag weight, Al-Saleem etal. (2016). Alsaleem study
found that 72.46% of their sample size had inappro-
priate school bag weight. Approximately the percent-
age was similar between our study and theirs, Al-Sal-
eem et al. (2016). We found that female bags weight
FIGURE 2. Appropriateness of Weight of school bag of subjects with shoulder tilt (n= 134)
Table 4. Gender comparison
Female 100 (50%)
Gender (n=200) Chi square P-value
Male 100
(50%)
Is the schoolbag weight appropriate
(10% of the student’s body weight)
(n=200)
Appropriate 5(20%) 20(80%)
0.650 0.420
Not appropriate 46(42.2%) 63(57.8%)
Pain and tilt (n=83)
Yes 19(45.2%) 33(80.5%)
11.017
0.001
No 23(54.8%) 8(19.5%)
Tilt (n=200)
Yes 49(74.2%) 17(25.8%)
23.157
0.001
No 51(38.1%) 83(61.9%)
Bag Content (n=200)
Necessary things 22(22.0%) 34(34%)
3.571 0.059
Extra things 78(78%) 66(66%)
406 EFFECT OF SCHOOL BAGS ON BODY MECHANICS AMONG SAUDI CHILDREN BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS
Fayz S Al Shahry etal.
is slightly higher than male. Likewise, Alsaleem et al.
results have shown that female student’s school bags are
heavier than male student’s school bags. Also, a study
found that female carried heavier schoolbags than male,
Kellis etal. (2010).
The mean weight of school bags was 4.82 ±1.536 Kg,
ranging from 2 kg to 14 kg, statistically signi cant at
0.05. All the students had a backpack and carried their
back packs over two shoulders. Likewise, in Dockrell,
Simms, and Blake study the mean schoolbag weight (4.8
± 1.43 kg) and the majority (85%) carried their school
bag over two shoulders. According to the age group, the
percentage of students with inappropriate school bag
weight was highest for students with ten years (90.6%).
Inconsistent with another study, the relative bag weight
was signi cantly heavier in the younger age group (ages
6–8 years), Kellis etal. (2010). Pain was highest among
student with 11 years’ students (n=26) 13 (50%) and
lowest in 9 years (n=110) 41 (37.2%).
According to the measurement ndings (PALM) we
found that out of the students with shoulder tilt (n=134)
51(38%) of them were female while 83 (61.9%) of the
male. We concluded that males have more shoulder tilt
than female. Thus, the shoulder tilt correlated with the
schoolbag weight (n=134), as a male with shoulder tilt
and carried inappropriate school bag weight 63(57.8%)
were more than female with shoulder tilt and carried
inappropriate school bag 46(42.2%). The percentage of
students who had shoulders tilt with inappropriate bag
weight (81%) was higher than those with appropriate
school bag weight (19%).this goes in line with the obser-
vations and recommendations of Dockrell et al.(2015)
and Patiletal.(2016)
.
The majority of male (66%) and female (78%) had extra
bag items such as coloring books, and toys. In the Dock-
rell etal. study, it was also found that the students’ bags
had additional details such as sports items and musical
instrument. These extra stuff increased the load carriage
on students. Inappropriate school bag increased the inci-
dence of pain and tilt in the shoulders. Carrying school
bag during morning line increased the incidence of pain
as most of the students who took their bags during morn-
ing line reported pain (50%). However, it did not show
any evidence of increasing the shoulder tilt see Table 5.
The most area of pain reported was a shoulder (70%)
this is matched the ndings in Reneman et al.(2006),
then (18%) in back. And the least reported was in their
neck (12%). Similarly, in the study of Dockrell et al.
(2015), the shoulders and the back were the most fre-
quently reported areas of schoolbag-related discomfort.
Students who reported pain (n=83) the majority felt pain
while carrying the bag (79.5%), then after carrying the
bag (14.5%), and the least had felt it all the time (6%).
Students who reported pain (n=83) Most of them had a
mild level of pain (46%), then moderate pain (42%) and
very few had severe pain (12%) this matched the result
of Spiteri etal. 2017. education for (32.5%) were made
about the effect of heavy school bags on their body
mechanics, but it was re ected negatively as we saw
that (80%)of them had inappropriate school bag weight
this indicated the poor response of the student to the
education, may due to habitual attitude witch need long
observation and correction by the family and the school
teachers.
The students who had both pain and tilt were 52 stu-
dents whom 19 (45.2%) female and 33 (80.5%) male stu-
dents with a P-value 0.001. Thus, not every student with
tilt was reported pain and vice versa. The presence of
shoulders tilt was higher than the incidence of pain this
goes in line with the ndings of Ghousia etal. (2018).
Limitations of this study was it is only conducted in
one region and Strengths of this study were that it con-
sidered other factors besides the bag’s weight; the books
should be uni ed from Ministry of Education for both
public and private schools.
CONCLUSION
This study provided evidence that school bag weight has
an effects on body biomechanics which causes shoulders
tilt, and it also increased the incidence of pain. So, in
future, education for parents must be conducted to make
sure to prevent students from carrying bags exceeding
the acceptable standard limit. The percentage of students
with inappropriate school bag weight is high, so further
research should investigate in depth the reasons for car-
rying heavy bags among primary school students.
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408 EFFECT OF SCHOOL BAGS ON BODY MECHANICS AMONG SAUDI CHILDREN BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS