Association of Backpack Loads and Wearing Time with Musculoskeletal Disorders in School Children of Wah Cant Pakistan: Correlational study

Background: Young children are carrying heavy bags to and from their schools. The use of backpacks increases recently because of several factors, including decreased availability of school lockers, increased homework, text books & other belongings being carried to school. All these factors amplify backpack weight which have drastic effects on young students’ musculoskeletal system. Methods: This was a correlational study. Data collection was done between Septembers to December 2018. The inclusion criteria were healthy young boys and girls of school children, with no known history of any musculoskeletal disorder or any other deformity or pathology. Survey was done through self-structured questionnaire and Nordic Musculoskeletal questionnaire. SPSS 21.0 was used for data analysis. Results: A total of 1104 students were included in the study, mean age of the students was 11.90 ± 2.2 (range 8-15) years. There were 48.4% males while 51.6% were females. Frequency of fatigue due to heavy backpack was 61.6%.Neck pain was common in 40.2% students, shoulder pain in 47.4% and the frequency of low back pain was 46.6% .According to BMI 33.2% students had normal BMI and 32.6% students were very severely underweight which is an alarming situation. The correlation of bag pack weight with students BMI was weak positive(r=0.25, p<0.05) Conclusion: This study concluded that the frequency of musculoskeletal pain was high due to carrying heavy backpacks. Upper and low back pain were the most common type. Maximum students carry >16% ratio of backpacks load. Wearing time of backpack was more than 10 minutes. A study was conducted by Brewer JM et al which revealed that ergonomic mismatch had limited impact on the body discomfort. It appears that other factor such as backpack weight and time carrying may contribute more to the discomfort of students.(15) Musculoskeletal pain, fatigue and tiredness has negative effects on children’s quality of life (QOL) and on their academic performances (16). This study aimed to find the association of backpack loads and wearing time with musculoskeletal disorders in school children.

malnutrition and imbalanced diet in young children.(1) T he heavy backpack problem in young students and its correlation to different types of bad posture, as well as pain in particular parts of the back, has been an important issue over the last few years (2). Young children are developing irreversible back deformities because of the weight of the bags they carry to school (3). Half of children suffer back pain by the age of 14 and doctors are reporting a rise in cases of spinal abnormalities in pupils, including disfiguring curvatures known as scoliosis (4). Overloaded school bags that are up to double the size of those carried ten years ago are contributing to the surge, it is feared (5). Children's skeletons are still growing so carrying heavy bags can cause lasting damage to spine (6).
Many students are carrying their bags on one shoulder or are increasingly carrying them on the crook of their elbow, so are placing a great strain on the spine (7). A lot of the bags being used are bulky sports bags, which are twice the size of backpacks used a decade ago (4).
In developing countries like Pakistan there is no emphasis on health care of adolescent and effects of heavy loads on the back of children (8). Backpacks are commonly used by children in Pakistan and no remedial measures have been taken to solve this problem.
Back problems are becoming an increasing issue among schoolchildren and schools no longer have adequate desk space for pupils to store heavy books (9). The use of backpacks increases recently because of several triggers, including decreased availability of school lockers, increased homework, larger text books & other belongings being carried to school (10). All these factors amplify backpack weight. Literature confirms that postural compensations and subjective complaints due to backpack loads and wear time in schoolchildren shows that typical backpack loads create worsening postural changes due to backpack loads and time spent carrying these loads (11,12). Carrying backpacks increases the risk of back pain and possibly the risk of back pathology (13). The prevalence of school children carrying heavy backpacks is extremely high. Preventive and educational activities should be implemented in this age group. (14) A study was conducted by Brewer was filled by the researchers after inquiring all the questions from the students. Each participant took almost 5-10 minutes to complete the survey. All data collected from them was coded in order to protect the identity of the students. For data analysis SPSS 21 was used. The frequency, percentages, mean and standard deviation of different variables were calculated. Independent sample T test was applied to find the difference among males and females, when comparison was made between different variables. One way ANOVA was performed for the statistics of backpack weight and BMI with grades of students. For correlation analysis Spearman was used for ordinal variables and Pearson's for continuous variables.

Results
Total 1104 school children were included in sample. The mean age of students was 11.1±2.2 years. 534 (48.4%) were male students and 570(51.6%) females participated in this study. Out of these students 540(48.9%) students were from public institutes and 564(51.1%) were from private institutes. The number of students who carry backpacks on both shoulder were 934 (84.6%) and those who carry backpacks on one shoulder were 170(15.4%). About 555(50.3%) students use to walk, 268(24.3%) use bike, 158(14.3%) use car and 123(11.1%) use bus as a means of transport to school. The mean BMI (kg/m 2) of students was 16.7±0.49 and mean weight (kg) of bag packs was 5.3±2.1. The Duration of carriage of Backpack (min) was 13.2±2.1.     (26). The limitations of this study was its crosssectional nature which does not permit cause and effect interpretation of its findings proper postural analysis of students was not done. It is recommended that the results from this study will help in suggesting and supporting improvements to be taken regarding heavy school bag issue. The findings of this study depicted that majority of students were having low body mass which is an alarming situation and badly affected their quality of life. Bag packs weight and student's weight should be in equal ratio for good health of students. Schools should provide lockers. In this way the weight of school bag will remain in safe range.

Conclusions
The frequency of musculoskeletal pain was high due to carrying heavy backpack. Upper and low back pain were the most common type of pain. Maximum students carry >16% ratio of backpack and wearing time of backpack was more than 10 minutes, that is an alarming issue for parents and it will cause musculoskeletal disorders in future. Way of carrying bag, heavy schedule and method of transport were the defining factors among school children