Mwaka ES, Munabi IG, Buwembo W, Kukiriza J, Ochieng J. Anatomy Department Makerere University, School of Biomedical Sciences

Introduction Schoolbag are important for carrying scholastic materials and lunch packs. Children carry heavy bags loaded with books. Recommended safe load limits 10%-15% of body weight. Low back pain prevalence between 30%-50%. Taimela,1997 Schoolbags associated with back pain Grimmer, 2000

No studies describing the actual current use of schoolbags by pupils in Uganda No data against which guidelines for weight limits can be set and for designing injury prevention programs.

Objectives The main objective of the study was to determine the prevalence of back pain and describe its relationship with schoolbag use in children. Specific objectives To determine the prevalence of low back pain in school children. To determine the average schoolbag load carried by school children and investigate its association with back pain. Comparisons were made between rural and urban school children. To investigate schoolchildren’s subjective perceptions of their daily schoolbag loads, to ascertain whether an association exists between these sensations or the load itself and back pain.

Methods Cross-sectional descriptive study design 532 children from 3 rural and 3 urban primary school Parental informed consent and pupil assent were sought. Questionnaire was used. Weight with and without the schoolbag was taken and the difference recorded

Variables Outcome variable was low back pain was operationally defined as pain or discomfort in the low back region, from the lower rib curvature to the lower part of the seat region. Predictor variables included: body weight, schoolbag weight, schoolbag weight as % of body weight, type of schoolbag, how the bag was carried, pupil perception of bag weight and comfort while wearing the bag, and activities done after school.

Analysis Data imported into Stata 10.0 Responses were analyzed using frequency distributions and descriptive statistics. Chi-square cross tabulations Nonparametric tests for trend Two- sample t test with equal variances Regression analysis P<0.05 was significant.

Results Females =294 (55.4%) and males = 237 (44.6%). Mean age 13.6 years (range years ). The mean age of children from the urban schools was compared with for the rural schools. The overall mean weight of the school children was kg + 9.1(range kg). (Males , females ).

Mean schoolbag weight was 3.78 kg (range kg). Mean bag weight as a percentage of the body weight was 8.46% (range %). Urban pupils were carrying significantly heavier bags (mean 10.58% ) than rural school children (mean 6.59% ) (p<0.0001). Schoolbag weight as a percentage of body weight plotted against age

12 year old carrying a bag 23.5% of his body weight 164/532 pupils (30.8%) carrying bags which were more than 10% of their body weight 122 (74.4%) pupils were from urban schools and 42 (25.6%) from rural schools.

Schoolbag use Type of bagUrban (n= 254)Rural (278) Backpack203 (79.9)102 (36.7) Shoulder bag45 (17.7)78 (28.1) Rack suck0 (0)20 (7.2) Other No bag 6 (2.4) 0 (0) 35(12.6) 43 (15.5) Bag features Padded shoulder straps237 (44.5) Adjustable Shoulder straps 304 (57.1) Chest strap19 (3.6) Waist belt38 (7.1) Padded back144 (27.1) Method of carriagen= 509 Both shoulder straps264 (51.9) One shoulder strap146 (28.7) Use of hip belt3 (0.6) Other method38 (7.5) Do not use bag58 (11.4) Type of school bag safety and comfort features, and method of bag carriage. Only 24/532 (4.5%) routinely Used all the bag features. All had scholastic materials in the bags, 28.3% had lunch Packs/ water bottles

Mode of transport Urban (n= 251) Rural (276) Walking137 (54.6)240 (87) Bicycle1 (0.4)9 (3.2) Car64 (25.4)7 (2.5) Taxi/ Bus36 (14.3)18 (6.5) Motorcycle13 (5.2)2 (0.7) Time spent carrying bag to school n= 252n= 276 <5 minutes71 (28.2)37 (13.4) minutes75 (29.8)57 (20.7) minutes34 (13.5)22 (8) minutes31 (12.3)42 (15.2) >30 minutes41 (16.6)118 (42.7) Time spent carrying bag from school n= 252n= 276 <5 minutes67 (26.6)30 (10.9) minutes41 (16.3)34 (12.3) minutes37 (14.7)29 (10.5) minutes37 (14.7)51 (18.5) >30 minutes70 (27.8)132 (47.8) Mode of transport and time spent carrying the school bag 77.7% walked to school 57.4% carried bags for <20 mins Duration of school bag carriage between urban and rural pupils p<

Only 101/532 (19%) had lockers

Body pain 448/532(88.2%) had pain or discomfort in the body over the previous 2 weeks. Pain greatest in the neck (24.5%), shoulders (42.1%), upper back (35.7%) and the lower back. 201/532 (37.8%) had low back pain. Females were more significantly affected (odds ratio 0.54, 95% CI ).

Urban(n= 253) Rural (n= 278) Odds ratio95% CI Sitting for long18 (7.1%)26 (9.4%) Walking for long33 (13)16 (5.8) Carrying the bag92 (36.4)96 (34.5) Writing1 (0.4)3 (1.1) Sports/ playing13 (5.1)11 (4.0) Comparison by sexBack pain No back pain Male66 (27.8)171 (72.2) Female135 (45.9)159 (54.1) Significant associations with LBP Walking for long periods (z= 6.95, r= 0.30, p< ). Type of school bag carried (z= -3.39, 95% CI to -0.20, P= 0.01). Method of schoolbag carriage (95% CI , p< ). Factors associated with low back pain

Low back pain cont’d Activities done after school did not have a significant effect on back pain. (p= 0.37). 212/523 (40.5%) on average spent between 2- 4 hours seated every evening and this significantly affected the occurrence of low back pain (z=-3.063, r= p= 0.02). 48/532 (9.3%) had ever missed school 148/518 (28.6%) had ever had to rest or not play sports 36 / 520 (6.9%) had ever been taken to the doctor because of back pain.

Pupils perceptions 119/305 (38.5 %) did not like their bags Medium (242/532, 49.9%) Heavy (193/532, 39.8% (p<0.0001) 49.8% felt uncomfortable ( pupils with pbw >10% p< Rural pupils twice as likely to complain of LBP Odds ratio % CI ).

Discussion Pain in the neck, shoulders and back is associated with carrying heavy loads. Heavy school bags result in postural changes at the head and trunk leading to repetitive strain injuries to the growing body. Professional bodies put limits at 10%- 15% of body weight.

What sort of bag should school children carry? Backpack Wide, padded shoulder straps for comfort and greater distribution of weight across the shoulders. Adjustable straps to allow varied placement of the backpack on the user’s back Padded back for comfort and protection Multiple compartments for distribution of load. Proper use: Two straps

How you recognize a heavy schoolbag? Key signs that bag is heavy: struggling to put on or take off the schoolbag, postural mal-alignment (forward head and/or trunk flexion or lateral listing), and pain and/or paresthesia associated with wearing the schoolbag. When a child complains that the bag is heavy take him/her seriously! Parents seldom check the weight and contents of children’s schoolbags.

Conclusion A significant number of pupils in the urban schools had school bags that were more than 10% of their body weights and significantly heavier than the school bags of older pupils in rural schools. The prevalence of LBP was 37.8%. Association was observed between low back pain and; type of schoolbag, method of bag carriage, and the time spent sitting after school.

Recommendations Parents remain the best advocates for safety promotion and should represent the group most likely to help to significantly reduce the number of schoolbag related injuries by checking backpack weights and contents Provision of lockers and functional libraries. Recommended schoolbags should be backpacks with ergonomic features designed to improve safety and comfort.