Schoolbag weight limit: can it be defined?

Comparison of muscle activity in school students while carrying backpacks and trolley bags

BACKGROUND

Trolley bags have gained popularity among students, but there is limited research comparing them to backpack-style school bags.

OBJECTIVE

This study aimed to compare how carrying a backpack versus a trolley bag affects the activity of trunk and lower limb muscles in secondary school students.

METHODS

Electromyographic activity was measured in 25 students (13.4±1.1 years) as they walked on level ground and up/down stairs while carrying both types of bags. The activity of the gastrocnemius, tibialis anterior, semitendinosus, rectus femoris, lumbar erector spinae, and rectus abdominis muscles was assessed on both the dominant and non-dominant sides.

RESULTS

The study found significantly reduced muscle activation in most of the targeted muscles when walking on level ground with the trolley bag and when going up/down stairs with the backpack.

CONCLUSIONS

Lifting a trolley bag depends on the slope of the walking surface and is more efficient on level ground, while carrying a backpack is more efficient when going up and down stairs. Since it is not practical to switch bags when encountering stairs in schools, a bag with a mixed model design incorporating features of both trolley and backpack may be more beneficial and practical for students to use. Students, parents, and teachers should be aware of the injury risks associated with carrying different types of bags.

Clinical examination and imaging resources in children and adolescent back pain

Back pain is a relatively common complaint in children and adolescents. The pediatric patient presenting with back pain can often be challenging, and there are many well-known organic diagnoses that should not be missed. In younger children, an organic cause of back pain can often be found. However, back pain in older children and adolescents is often "non-specific." The differential diagnosis of back pain in children includes neoplasms, developmental, and inflammatory conditions. Basic steps should include an in-depth anamnesis, a systematic physical examination, and standard spine radiographs (anteroposterior and lateral). Nevertheless, advanced diagnostic imaging and laboratory studies should be included when indicated to avoid missing or delaying a serious diagnosis. If other types of imaging tests are necessary (magnetic resonance imaging, computed tomography, bone scan, or single photon emission computed tomography), they should be guided by diagnostic suspicion.

The Influence of the Weight of the Backpack on the Biomechanics of the Child and Adolescent: A Systematic Review and Meta-analysis With a Meta-Regression

PURPOSE

To evaluate and explore the influence of the weight of a backpack on standing posture and gait in children and adolescents.

METHODS

We conducted a search of MEDLINE (PubMed), Cochrane Library, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Web of Science, with the last search in July 2021. Standardized mean differences (SMD) and 95% confidence intervals were calculated for relevant outcomes and were pooled in a meta-analysis using the random-effects model. The participants were healthy children or adolescents. The outcomes were postural variables, spatiotemporal gait variables, gait kinematics, and muscle activity. We analyzed the influence of a loaded backpack on posture while standing and spatiotemporal and kinematic variables while walking. We used GRADE, Risk of Bias 2, ROBINS-I, MINORS, and PEDro scales to rate the quality, certainty, and applicability of the evidence.

RESULTS

Wearing a loaded backpack induces a significant increase of the craniohorizontal angle while standing and a decrease of walking speed and stride length while walking. Only the craniovertebral angle had a significant relationship with the weight of the backpack.

CONCLUSIONS

Wearing a backpack induces postural changes while standing and affects gait in children and adolescents; however, almost all the changes are not related to the backpack weight.

Influence of School Backpack Load as a Variable Affecting Gait Kinematics among Seven-Year-Old Children

This article investigates schoolchildren's ability to carry an additional load using a backpack (BP). According to scientific research, there is no precise limit to the maximum backpack load, which varies from 10% to 15% of body weight (BW). The purpose of this study was, therefore, to evaluate the influence of an additional external load carried using a backpack on gait kinematics among seven-year-old children in Poland, including assessment of the gender differences. The study was conducted among 26 (13 boys and 13 girls) primary school children aged seven years. The children walked at their preferred speed, under four conditions: with no load (0% BW) and with 10%, 15% and 20% BW. Spatiotemporal parameters were measured using the 2 m Footscan® platform system and photocell Sectro timing system. The children walked more slowly under an additional load. Their step length and single support time decreased. Their base of support, step time and double support time increased. There was no significant effect on their stride length or gait cycle time. The gait kinematic changes were most evident between 10% BW and greater loading. The results highlight how children's gait is affected by carrying additional external loads, which should not exceed 10% BW. That limit is appropriate for both genders.

School Bag-Related Factors and Their Implications for Walking and Cycling to School among New Zealand Adolescents

Excessive school bag weight may be a modifiable barrier to active transport to school. This study examined correlates of school bag weight and adolescents’ perceptions of excessive school bag weight for walking and cycling to school among New Zealand adolescents living in diverse settlement types. Adolescents (n = 1512; 15.0 ± 1.3 years) completed a questionnaire and had their bag weight (n = 1190) and body weight (n = 1038) measured. Adolescents using active transport and rural adolescents had lighter school bags compared to their counterparts. One-third of adolescents reported excessive school bag weight for walking (31.2%) and cycling (37.2%) to school. Positive correlates of relative school bag weight were female gender (regression coefficient (95% CI): 0.53 (0.13, 0.93)), and underweight (2.21 (1.39, 3.02)), whereas negative correlates were Māori ethnicity (−0.87 (−1.41, −0.32)), overweight (−1.84 (−2.35, −1.34)) and obesity (−3.57 (−4.26, −2.87)), and school location in small urban areas (−2.10 (−4.19, −0.01)), and rural settlements (−3.58 (−5.66, −1.49)). Older adolescents, females, those with greater relative school bag weight, and those experiencing school bag-related pain symptoms and/or fatigue were more likely to report excessive school bag weight for both walking and cycling to school. Future initiatives should target reducing excessive school bag weight, particularly in female and urban adolescents.

Prevalence of Musculoskeletal Pain and Its Relation With Weight of Backpacks in School-Going Children in Eastern India

Background: Recently, heavy school backpacks have become a significant concern among parents and health professionals, as well as the media, but evidence for the same is limited in the Indian context.

Aim: To find the prevalence of musculoskeletal pain among school-going children and its relationship with backpack weight.

Design: Cross-sectional study.

Method: This study was carried out among school-going children from grade 6 to 10 with age of 10 to 16 years from an urban and rural location. Schools were selected randomly from all enlisted schools in the district of Khurdha, Odisha state of India. A structured questionnaire was administered to assess symptoms of musculoskeletal pain. Anthropometric measurements along with backpack weight were taken.

Statistical Analysis: Chi-square test was performed for categorical variables and Student's t-test for continuous variables. Multivariate regression analysis was performed to identify factors with maximum effect on musculoskeletal pain.

Results: The prevalence of musculoskeletal pain was 18.8% in the preceding year. Backpacks weights were higher among children of urban schools as compared with rural areas. Children from urban schools were more likely to have pain than those from rural schools (OR 1.88, 95% CI 1.41–2.49). Those children with a backpack weight more than 10% of body weight had almost twice the risk of musculoskeletal pain compared to backpack weight less than 10% (OR 1.91, 95% CI 1.4–2.6) in univariate analysis where as no significant association was found on multivariate analysis.

Conclusion: The prevalence of musculoskeletal pain was high in school-going children. In children, carrying higher backpack weight, and a higher percentage of the backpack to bodyweight had a significant association with musculoskeletal pain. Gender, height, body mass index, and backpack weight to body weight > 10% had no association with musculoskeletal pain.

Prevalence and factors associated with low back pain in schoolchildren in Cameroon, sub-Saharan Africa

BACKGROUND

Data on the prevalence and factors associated with low back pain (LBP) in schoolchildren are scarce in Africa, particularly in sub-Saharan Africa.

OBJECTIVES

To assess the prevalence and factors associated with LBP in schoolchildren in Cameroon.

PATIENTS AND METHODS

We performed a cross-sectional study in 10 randomly selected schools (public and private) in Douala, Cameroon. Using a self-administrated questionnaire, sociodemographic, usual physical activity, and clinical data were collected and all the schoolbags were weighted. Informed consent was obtained from the parents. Statistical significance was established at P < .05. Logistic regression was performed to identify factors associated with LBP.

RESULTS

We included 1075 schoolchildren (543 boys, 50.5%). The prevalence of LBP was 12.3% (132 children: 81 girls and 51 boys). The mean age was 11 ± 1 years (range, 8-14 years). Body mass index was normal in 110 schoolchildren (83.4%). Sixteen schoolchildren had already met a physician for LBP. Among the factors evaluated, those associated with LBP were female gender, doing competitive sport, sitting position, and LBP in at least 1 parent. The mean weight of the schoolbags was 4.9 ± 1.9 kg. We had 99 children with LBP and a schoolbag weight ≥10% of their body weight. No association was found between the weight of schoolbag and LBP.

CONCLUSION

LBP is common in Cameroonian schoolchildren, where 12.3% suffer from it. The weight of schoolbags was not associated with LBP. However, female gender, competitive sport, sitting position, and parental history of LBP were significantly associated with its occurrence.

Altered cervical posture kinematics imposed by heavy school backpack loading: A literature synopsis (2009-2019)

Background

Habitual school backpack carriage causes neuro-musculoskeletal vertebral, shoulder and hand pain; deviated posture compromised cardiopulmonary function and proprioception.

Objective

Present a novel literature summary of the influence of backpack carriage associated with deviated cervical posture and compromised pulmonary function.

Method

An electronic literature appraisal adopting the Preferred Reporting Items for Systematic Reviews, using Google Scholar, Science Direct, EMBASE, AMED, OVID, PubMed and Sabinet search engines, was instituted during 2009–2019. Key search words: schoolbag, backpack, carriage, cervical posture and children. The quality of the studies was assessed using the Downs and Black Appraisal Scale.

Results

583 records were initially identified which was reduced to 14 experimental and observational studies. A total of 1061 participants were included across the 14 studies, with an average age of 11.5 ± 1.3 years, body mass of 37.8 ± 6.6 kilograms (kg), height of 1.41 ± 0.05 meters (m), backpack mass of 5.2 ± 0.9 kg and percentage backpack mass to child’s body mass of 13.75%. The studies mean rating according to the Downs and Black Appraisal Scale was 76.3%. The average craniovertebral angle (CVA) was 53.9° ± 14.6° whilst standing without carrying a backpack was reduced to 50.4° ± 16.4° when loaded (p < 0.05). Backpack loads carried varied from 5% – 30% of the participant’s body mass that produced a mean CVA decline of 3.5°.

Conclusion

Backpack carriage alters cervical posture, resulting in smaller CVA and compromised pulmonary function. There is no consensus of the precise backpack mass that initiates postural changes. Girls’ posture begin changes when carrying lighter backpacks as compared to boys of the same age strata.

Ergonomic factors of school bags and their adaptation to the weight of students

BACKGROUND

Students use a school bag to carry their school supplies which may not have the required standards and ergonomic factors.

OBJECTIVE

This study was aimed to examine the ergonomic factors of schoolbags and their adaptation to the weight of elementary school students.

METHODS

This cross-sectional study was carried out on 721 primary schoolchildren. To collecting data a checklist, which its final version was approved by the experts, was designed by researchers. Data were analyzed by using SPSS ver. 22 and Chi-square test, One-Way ANOVA, and univariate and multivariate logistic regression models.

RESULTS

In this study, about 90.1% of students used a backpack to carry their items and most students carried backpacks with a weight up to 10% of their body weight. In 43.5% of the students, waist width was appropriate with backpack width at the bottom, and in 96.6% shoulder width was appropriate with backpack width at the top. Multivariate logistic regression showed that girls in compared to boys were more likely tolerated ratio of backpack weight to body weight, and also had more likely proportion of waist width and the backpack width at the bottom. The grades of the first, second, and fourth used more heavy backpacks. Students who their mothers were employee compared to housewives, carried heavier backpacks and had more likely proportion of waist width and the backpack width at the bottom. As the mother's age increased, the proportion of waist width and the backpack width at the bottom is diminished.

CONCLUSION

The schoolbags weight of many students was more than the standard weight, and their schoolbags did not have the required standards. Educational interventions can increase the knowledge of students and parents about the ideal weight of a schoolbag and the criteria for choosing a proper school bag.

Relationship between School Backpacks and Musculoskeletal Pain in Children 8 to 10 Years of Age: An Observational, Cross-Sectional and Analytical Study

Back pain in children is a reality and various factors are involved in its etiology. The study’s aim was to analyze the relationship between the use and type of backpack and pain in children. An analytical observational cross-sectional study was conducted among 123 schoolchildren between 8–10 years. Data on the participants’ weight and height and their backpacks were collected, as well as the way of travel to school and their physical activity during the week. The results indicated that all backpacks were large because the backpack’s height is longer than torso length. Participants who studied in a traditional educational system (62.60%) carried backpacks that exceeded 10% of their body weight. Additionally, 31.7% of the students presented pain. There is no significant correlation between the weight or type of backpack and the pressure pain threshold collected from shoulders muscles. Participants who carried backpacks heavier than 10% of their body weight did not have more musculoskeletal pain or a lower pressure pain threshold than the others, although they did report greater fatigue. All these topics should be debated considering the student’s social environment and the backpack’s discomfort to the children, even though no relationship was found between musculoskeletal pain and backpack weight.

Factors associated with non-specific low back pain in children aged 10-12 from Bucaramanga, Colombia: A cross-sectional study

BACKGROUND

There are no Colombian studies published that assess non-specific low back pain (NSLBP) risk factors in children.

OBJECTIVE

To determine the factors associated with NSLBP in 73 children (19.2% girls) aged 10-12 years in one military school in Bucaramanga, Colombia.

METHODS

A questionnaire was used to obtain information of risk factors. Subsequently, children's weight and height were measured. The backpack was weighed at the beginning of each day from Monday to Friday. Crude and adjusted prevalence ratios were calculated, with their respective 95% confidence interval (CI).

RESULTS

The one-month prevalence of NSLBP was 39.7% (95% CI 28.4-51.9). In the multivariate analysis, carrying backpacks wearing between 12% and 20% of body weight, having a perception that the backpack is very heavy, and being a passive smoker increase the likelihood of NSLBP, while being 11-year-old compared to 10-year-old decreases the likelihood of having NSLBP, adjusted for gender, body mass index, and history of LBP in parents.

CONCLUSIONS

High prevalence of low back pain was found in children between 10 and 12 years old. The study of the decisive factors of low back pain is important to identify children at risk, as well as to develop efficient primary prevention programs.

Effects of Backpacks on Ground Reaction Forces in Children of Different Ages When Walking, Running, and Jumping

Backpacks for transporting school loads are heavily utilized by children, and their mechanical advantages have been allowing children to transport heavy loads. These heavy loads may increase ground reaction forces (GRFs), which can have a negative effect on joints and bone health. The aim of this study was to investigate the effect of backpacks on the GRFs generated by children during walking, running, and jumping. Twenty-one children from the fifth (G-5, n = 9) and ninth (G-9, n = 12) grades walked, ran, and jumped over a force plate. When walking, the G-5 had GRF increments in the first (17.3%; p < 0.001) and second (15.4%; p < 0.001) peak magnitude, and in the total integral of the vertical force (20%; p < 0.001), compared to the control condition (i.e., no backpack), and the G-9 had increments of 10.4%, 9%, and 9% (p < 0.001), respectively. The G-9 did not prolong their total stance time (p > 0.05), unlike the G-5 (p = 0.001). When running, total stance time increased 15% (p < 0.001) and 8.5% (p < 0.001) proportionally to the relative load carried, in the G-5 and G-9, respectively. Peak GRF did not increase in any group when running or landing from a jump over an obstacle. It was found that GRF was affected by the backpack load when walking and running. However, when landing from a jump with the backpack, schoolchildren smoothed the landing by prolonging the reception time and thus avoiding GRF peak magnitudes.

Normative values for relative schoolbag weight in primary school children aged 6-14 from Czech Republic: A pilot study

Little evidence from observational studies has been provided regarding ‘optimal’ relative schoolbag load during primary education. Also, no study to date has provided reference-based standards for relative schoolbag weight. Therefore, the main purpose of the study was to establish normative values of relative schoolbag weight in a sample of children. In this cross-sectional study, we recruited 584 primary school students aged 6–14 (mean_age±SD = 9.6±2.4 yrs, mean_height±SD = 1.4±0.2 m, mean_weight±SD = 37.5±13.3 kg, mean_{body-mass index}±SD = 17.6±3.1 kg/m², 44.4% girls) chosen from five schools in the city of Brno. Schoolbag weight and child’s body weight were objectively measured by using digital scale. Relative schoolbag weight was calculated by dividing schoolbag weight with child’s body weight and the result was expressed in percentage. Lambda, Mu and Sigma (LMS) method was used to create sex- and age-percentile curves. Boys carried slightly heavier schoolbag, compared with girls (mean difference 0.2 kg, p = 0.020). No significant differences between sexes in relative schoolbag weight were observed (p = 0.240). Median values (P50) for boys and girls were similar and the largest observed between ages 6–9 in boys (15–17%) and 6–8 in girls (16–18%). The percentage of children carrying relative schoolbag weight beyond 10% of their body weight was very high, especially between ages 6–10 in boys (85.1–100%) and 6–11 in girls (86.8–95.4%). This study provides first sex- and age- relative schoolbag weight normative values in primary school children. Future studies should use similar methods for generating comparable data.

Schoolbag weight carriage in Portuguese children and adolescents: a cross-sectional study comparing possible influencing factors

BACKGROUND

Schoolbags and the consequences of carrying them, particularly those associated with overload, are often studied as a health concern. Modifications in gait and posture were reported when children carried loads that corresponded to more than 10% of their body weight (BW). The aims of this study were to verify the load that is carried by Portuguese students and how it is influenced by factors such as school grade, school schedule, lunch site, physical education, sex and body mass index (BMI). Acquiring a more specific knowledge of the Portuguese context and understanding the influence of these factors may allow us to generate proposals to control them in ways that benefit students.

METHODS

The load carried by students in the 5th grade (10.6 ± 0.4 years) and 9th grade (14.7 ± 0.6 years) were weighed with a luggage scale on all days of the week, resulting in 680 evaluations. Data related to the school day were also collected, such as the student's lunch site, how he or she got to school and his or her school schedule for that day. Individual height and weight were also assessed.

RESULTS

The 5th grade students carried greater loads than the 9th grade students, resulting in a substantial difference relative to their BW. The school loads of the 5th grade students were mostly greater than 10% of their BWs. Girls tended to carry heavier loads than boys, and overweight students also tended to carry heavier loads. Students who could eat lunch at home carried less weight, and on physical education days, the total load carried increased, but the backpacks of the 5th grade students were lighter.

CONCLUSIONS

The results of the current study describe excessive schoolbag weight among Portuguese students and expound on some of the factors that influence it, which can help researchers and professionals design a solution to decrease children's schoolbag loads.

Adolescent idiopathic scoliosis for the primary care physician: frequently asked questions

PURPOSE OF REVIEW

Provide primary care physicians with the best available evidence to support answers to frequently asked questions by caregivers of patients with adolescent idiopathic scoliosis (AIS).

RECENT FINDINGS

A review of best available evidence shows that schoolbag design and weight are not associated with higher odds of developing AIS. However, patients with AIS are more prone to balance problems with asymmetric backpack carrying and with rising weights. In patients with AIS, the backpack should be worn in a symmetric way and should never exceed 10% of the child's body weight. Although no relationship was found between systematic exercising in general and development of AIS, classical ballet and professional swimming in skeletally immature adolescents were associated to higher odds of having AIS. Since AIS affects adolescent girls mainly, women health issues are of paramount importance in this disease. Except for limited sexual activity and higher need for infertility treatment, patients with AIS perform similar to controls in marriage rates, age at first pregnancy, gestational age, offspring, labor and delivery. Best available evidence shows that adults with AIS diagnosed during adolescence have similar physical activity level compared with controls. In patients with AIS, adults with surgically treated idiopathic scoliosis have slightly lower physical activity level than previously braced and untreated patients.

SUMMARY

Although schoolbag weight isn't associated with higher odds of developing AIS, classical ballet and professional swimming in adolescents are. Except for limited sexual activity, patients with AIS perform similar to controls in remaining women health issues. Adults with AIS diagnosed during adolescence have similar physical activity level compared with controls.

Intervention Study for Reducing Schoolbag Weights in Two Rural Schools in Maharashtra

Context

Heavy schoolbags are reported worldwide including India. The prescribed safe upper limit was 10% of student bodyweight.

Aims

This intervention study explored (a) impact of awareness measures among stakeholders and (b) any systemic constraints for reducing bag loads.

Settings and Design

This is a two-stage intervention study following a 2016-2017 baseline study of schoolbag weights in two rural schools.

Subjects and Methods

The study involved 175 students (male: 79 and female: 96) from 8^th to 9^th standards. The intervention consisted of sharing the baseline findings of schoolbag weight, guidelines, and necessary measures for the same. Thefirst intervention involved creating awareness among teachers regarding the harmful effects and the second intervention involved students. Bag weights were recorded on digital luggage scale in prelunch sessions in the following weeks after the intervention.

Statistical Analysis

The impact of interventions was tested with (a) Paired t-test for mean bag weights and (b) Chi-square test for the proportion of heavy schoolbags.

Results

The mean baseline bag weight of 3.77 kg declined statistically significantly after successive interventions to 3.4 and 3.2 kg. The baseline proportion of 51% of heavy bags (>10% of body weight) declined to 38% and 29%. Despite interventions, 19% students in 8^th carried heavier bags than the 3.4 kg cap set by Government guidelines. Subjects taught in 8^th standard were above 6/day.

Conclusions

Awareness programs for stakeholders only partially succeeded in reducing bag weights. Hence, reducing the daily subject load is necessary.

School Bag Weight as a Barrier to Active Transport to School among New Zealand Adolescents

Background: Excessive school bag weight is a barrier to active transport to school (ATS). This study examined parents’ and adolescents’ perceptions of school bag weights and actual school bag weights for adolescents in New Zealand. Methods: Parents (n = 331; 76.7% women) completed a survey. Adolescents (n = 682; age 15.1 ± 1.4 years; 57.3% boys) completed a survey, underwent anthropometry, and had their school bags weighed. Results: Overall, 68.3% of parents perceived that adolescents’ school bags were too heavy to carry to school. This parental perception differed by adolescents’ mode of transport to school (active/motorized/combined: 35.1%/78.4%/68.8%, p < 0.001). Adolescents perceived that their school bags were too heavy to carry to walk (57.8%) or cycle (65.8%) to school. Adolescent perceptions differed by mode of transport to school (for walking (active/motorized/combined): 30.9%/69.2%/55.9% agree, p < 0.001; for cycling: 47.9%/72.8%/67.7%; p < 0.001). Actual school bag weight was, on average, 5.6 ± 2.1 kg. Relative school bag weight (% of body weight) was higher for boys and underweight adolescents compared to their counterparts. Neither absolute nor relative school bag weight differed by mode of transport to school. Conclusions: School bag weight was perceived a barrier to ATS and was a greater perceived barrier among users of motorized versus active transport. Perceptions of school bag weights should be considered in future ATS interventions.

Do schoolbags cause back pain in children and adolescents? A systematic review

OBJECTIVE

To investigate whether characteristics of schoolbag use are risk factors for back pain in children and adolescents.

DATA SOURCES

Electronic searches of MEDLINE, EMBASE and CINAHL databases up to April 2016.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Prospective cohort studies, cross-sectional and randomised controlled trials conducted with children or adolescents. The primary outcome was an episode of back pain and the secondary outcomes were an episode of care seeking and school absence due to back pain. We weighted evidence from longitudinal studies above that from cross-sectional. The risk of bias of the longitudinal studies was assessed by a modified version of the Quality in Prognosis Studies tool.

RESULTS

We included 69 studies (n=72 627), of which five were prospective longitudinal and 64 cross-sectional or retrospective. We found evidence from five prospective studies that schoolbag characteristics such as weight, design and carriage method do not increase the risk of developing back pain in children and adolescents. The included studies were at moderate to high risk of bias. Evidence from cross-sectional studies aligned with that from longitudinal studies (ie, there was no consistent pattern of association between schoolbag use or type and back pain). We were unable to pool results due to different variables and inconsistent results.

SUMMARY/CONCLUSION

There is no convincing evidence that aspects of schoolbag use increase the risk of back pain in children and adolescents.

Effects of backpack load and position on body strains in male schoolchildren while walking

Data regarding the effects of backpack carriage on children’s body strains while walking are limited. This study measured the body posture, muscle activation, and subjective discomfort scores of 12 male schoolchildren (age: 12.3 (range 12.1–13.0) y, height: 151.3 (range 144.2–154.6) cm, weight: 46.6 (range 43.6–49.7) kg) carrying backpacks weighing 5%, 10%, and 15% of their respective body weights (BWs) and walking for 10 min on a treadmill. For each load, three positions along the spinal column (T7, T12, and L3) were examined. Participants carrying a backpack weighing 15% of BW exhibited higher head flexion, trunk flexion, and corresponding muscle activation, and a lower lumbosacral angle compared with those carrying loads of 5% and 10% of BW. The waist received the highest discomfort scores when the backpacks were carried at the L3 position. Conversely, the discomfort rating for the neck and shoulders where the highest when the backpack was at the T7 position; this high backpack position also caused more head flexion than the other two positions. For the musculoskeletal health of children, the findings suggest that carrying a school backpack weighing 15% of BW should be avoided, and carrying at the T12 position may be recommended for schoolboys.

Parental awareness of schoolbag carriage: A comparative study of Irish and United States parents

BACKGROUND

Given the global nature of schoolbag carriage, there has been extensive research on schoolbag weight and use with resultant guidance on many aspects of carrying a schoolbag. However, there is limited evidence of knowledge translation or parents' awareness of schoolbag carriage.

OBJECTIVE

This study investigated parental awareness of factors related to schoolbag carriage.

METHOD

A cross-sectional survey using an anonymous 30-item questionnaire and purposive sampling was used. Questionnaires were distributed to parents of primary school children through the schools. Descriptive statistics of frequencies and percentages were used and associations were tested using Chi-square analysis in SPSS v23.

RESULTS

A total of 700 parents in Ireland (Ire) and the United States (US) participated in the study (n = 444 [Ire] and n = 256 [US]). Generally, parents had satisfactory awareness of appropriate schoolbag type and carriage. The majority of children owned a backpack (89.9% [Ire] vs. 93.7% [US]), although fewer parents considered this to be the most suitable bag for their child (69.6% [Ire] vs. 88.2% [US]). More Irish parents (29.2%) favoured a wheeled schoolbag compared to US parents (6.2%) (p < 0.001). The majority (70.8% [Ire] vs. 55.7% [US]) wanted more information. The preferred platforms for receiving information were a handout (78.1% [Ire] vs. 71.6% [US]) and on-line (44.6% [Ire] vs. 53.9% [US]).

CONCLUSIONS

Despite gaps identified, parents had good awareness of factors relating to schoolbag carriage, but this study shows that they would like more information. The preferred platform for knowledge translation was a handout. Parents are the best advocates for safety promotion and represent the group most likely to improve schoolbag carriage among children.

Guidelines for schoolbag carriage: An appraisal of safe load limits for schoolbag weight and duration of carriage

BACKGROUND

There is no global agreement on a schoolbag weight limit and little assessment of its utility. The duration of carriage is another factor yet there is no previous systematic assessment of the utility of cut-off values for it in identifying schoolbag-related discomfort.

OBJECTIVES

The objectives were to establish if there was a threshold for musculoskeletal discomfort based on (i) percentage bodyweight (% BW) of the schoolbag; (ii) duration of carriage; or (iii) combined % BW and duration.

METHODS

Using data from 462 primary school children, a novel experimental approach was used to explore the utility of conventional schoolbag weight limit guidelines and duration of carriage. A receiver operating characteristic (ROC) curve was constructed to examine the predictive performance of schoolbag weight and duration of carriage.

RESULTS

The mean schoolbag weight (4.8±1.43  kg) represented a mean 12.4±4.18% BW. Only 30.7% of the sample carried schoolbags that were ≤10% BW. The majority (76%) carried schoolbags to school for ≤10 minutes. No % BW, duration of carriage or mechanical burden criterion provided a threshold cut-off point for accurately predicting schoolbag-related discomfort.

CONCLUSIONS

Guidelines for safe schoolbag carriage that are based on mechanical factors alone could not be upheld. The association between duration of carriage and back discomfort warrants further investigation.

Interaction of body mass index and age in muscular activities among backpack carrying male schoolchildren

BACKGROUND

The complex and limited understanding of the interactions among multiple factors associated with back pain occurrence among schoolchildren might explain the current inconclusive and contradictory findings on the issue. The global increase in the prevalence of childhood overweight and obesity, which reportedly affects children's physical abilities, calls for concern among school/children ergonomists and other stakeholders.

OBJECTIVE

The study investigated the interaction of body mass index (BMI) and age on the muscular activities, backpack height and perceived level of pain arising from carrying different weight of backpacks.

METHODS

Surface electromyography analysis of erector spinae and trapezius muscular activities was conducted on 47 primary schoolchildren aged between 8 and 11 years. Repeated measure ANOVA were carried out on the data.

RESULTS

There was significant difference in all the measures of muscular activities, backpack height and pain rating at different levels of backpack weight. However, the children were only significantly fatigable in the erector spinae muscles of the lower back and not in the trapezius of the upper back. The interactive effect of BMI was more pronounced than the children's age.

CONCLUSIONS

The study shows that it is not appropriate for all schoolchildren to have the same backpack weight limit and obese schoolchildren should carry a lower bag-to-body ratio of backpack weight. The younger children also need an appropriate bag surface-to-trunk ratio size of backpack as they were more affected by the position of the backpack.

Multi-objective analysis for assessing simultaneous changes in regional spinal curvatures under backpack carriage in young adults

Change in sagittal spinal curvature from the neutral upright stance is an important measure of the heaviness and correctness of backpack use. As current recommendations, with respect to spinal profile, of backpack load thresholds were based on the significant curvature change in individual spinal region only, this study investigated the most critical backpack load by assessing simultaneously the spinal curvature changes along the whole spine. A motion analysis system was used to measure the curvature changes in cervical, upper thoracic, lower thoracic and lumbar regions with backpack load at 0, 5, 10, 15 and 20% of body weight. A multi-objective goal programming model was adopted to determine the global critical load of maximum curvature change of the whole spine in accordance with the maximum curvature changes of the four spinal regions. Results suggested that the most critical backpack load was 13% of body weight for healthy male college students. Practitioner Summary: As current recommendations of backpack load thresholds were based on the significant curvature change in individual spinal region only, this study investigated the backpack load by considering simultaneously the spinal curvature changes along the whole spine. The recommendation, in terms of the global critical load, was 13% of body weight for healthy male college students.

The relationship between back pain and schoolbag use: a cross-sectional study of 5,318 Italian students

BACKGROUND CONTEXT

Back pain at a young age is considered to be predictive of chronicity. Several studies have investigated the relationship between the use of a schoolbag and back pain, although some aspects are still unclear.

PURPOSE

The aim of this study was to evaluate back pain due to schoolbag use in terms of (1) prevalence and intensity, (2) differences between male and female pupils, and (3) predisposing factors.

STUDY DESIGN

This is a cross-sectional study.

PATIENT SAMPLE

The sample was composed of 5,318 healthy pupils aged 6 to 19 years (classified according to three age groups: children, younger adolescents, and older adolescents).

OUTCOME MEASURES

Schoolbag-related pain was assessed by means of an ad hoc questionnaire. The intensity of pain was assessed using the Wong scale.

METHODS

Subjects underwent a face-to-face interview using an ad hoc questionnaire. The intensity of pain was assessed using the Wong scale. On the basis of the prevalence and intensity of back pain, we divided our population into two groups: (1) no or mild pain group and (2) moderate or severe pain group. The "schoolbag load" (ratio between schoolbag and pupil weight multiplied by 100) was calculated for each subject.

RESULTS

More than 60% of the subjects reported pain. Although the schoolbag load decreased from children to young and older adolescents, schoolbag-related pain significantly increased (p<.001). Girls reported significantly more frequent and more severe pain than boys. The logistic model confirmed that adolescent girls are the group at greatest risk of suffering from intense pain. The schoolbag load had a weak impact on back pain, whereas the schoolbag carrying time was a strong predictor.

CONCLUSIONS

Adolescent girls have the highest risk of experiencing severe back pain, regardless of schoolbag load. This suggests that other factors (anatomical, physiological, or environmental) might play an important role in pain perception. These aspects should be investigated to plan appropriate preventive and rehabilitative strategies.

Schoolbag carriage and schoolbag-related musculoskeletal discomfort among primary school children

Schoolbag carriage is a common occurrence and has been associated with musculoskeletal discomfort in children. The current study investigated the relationship between schoolbag-related musculoskeletal discomfort and individual, physical and psychosocial risk factors in primary school children in Ireland. A cross-sectional survey and pretest-posttest quasi-experimental design was used. The site and intensity of musculoskeletal discomfort was assessed before and after schoolbag carriage to provide a dose-response assessment of schoolbag-related discomfort for the first time. Objective measurements of the children, schoolbags and other additional items were made, and a researcher assisted questionnaire was completed on arrival at school. A total of 529 children (male 55.8%: female 44.2%) with a mean age of 10.6 years ± 7.14 months were included. The majority had backpacks (93.8%) and 89.7% (n = 445) carried the backpack over 2 shoulders. The mean schoolbag weight (4.8 ± 1.47 kgs) represented a mean % body weight (%BW) of 12.6 ± 4.29%. Only 29.9% carried schoolbags that were ≤10%BW. A significantly greater proportion of normal weight children carried schoolbags that were >10%BW compared to overweight/obese children (p < 0.001). The mean %BW carried was 18.3 ± 5.03 for those who had an additional item. The majority (77.5%) carried schoolbags to school for ≤10 min. The prevalence of baseline musculoskeletal discomfort was high (63.4%). Schoolbag-related discomfort was reported more frequently in the shoulders (27.3%) than in the back (15%). The dose-response assessment indicated that both statistically and meaningfully significant increases in discomfort were observed following schoolbag carriage. Multiple logistic regression models indicated that psychosocial factors and a history of discomfort were predictors of schoolbag-related back discomfort, while gender (being female) and a history of discomfort were predictors of schoolbag-related shoulder discomfort. None of the physical factors (absolute/relative schoolbag weight, carrying an additional item, duration of carriage, method of travel to school) were associated with schoolbag-related discomfort. This study highlights the need to consider the multi-factorial nature of schoolbag-related discomfort in children, and also the need to identify background pain as its presence can inadvertently influence the reporting of 'schoolbag-related' discomfort if it is not accounted for.

Impact of backpack type on respiratory muscle strength and lung function in children

We examine the influence of backpack type on lung function and respiratory muscle strength in children. Thirty-seven children were assessed for lung function and inspiratory and expiratory muscle strength under four randomly determined conditions: unloaded erect standing and three conditions carrying 15% of the child's body weight. In these three conditions, children carried the weight on a backpack with bilateral shoulder straps carried over both shoulders, on a backpack with bilateral shoulder straps carried over one shoulder and on a backpack with a mono shoulder strap. Significantly lower forced vital capacity, forced expiratory volume in one second and maximal expiratory pressure were observed when children carried a backpack with a mono shoulder strap compared to the unloaded standing position. In conclusion, the restrictive effect and the decrease in expiratory muscle strength were more pronounced for the backpack with a mono shoulder strap, suggesting that a double strap backpack is preferable to a mono shoulder strap backpack. Practitioner summary: There is little known about the effect of schoolbags on respiratory muscle function. We investigated the influence of backpack type on lung function and respiratory muscle strength. A backpack with a mono shoulder strap created a restrictive effect and a decrease in strength, suggesting that a double strap backpack is preferable to a mono shoulder strap backpack.

No kidding: low back pain and type of container influence adolescents' perception of load heaviness

PURPOSE

The relationship between low back pain (LBP) and the lifting/carrying of loads is still a matter of great discussion. In teenagers, the weight of the school bag has been considered to play a pathogenic role in LBP but the relationship between the actual weight of the school bag and LBP symptoms does not seem to be a straightforward one. Numerous factors have been identified that influence the perception of weight. This study aimed to evaluate the influence of low back pain and the type of container on the perception of load heaviness by healthy teenagers.

METHODS

A convenience sample of 80 healthy teenage males (mean ± SD age 13.9 ± 2.1 years) was recruited from the members of two local sports clubs. The volunteers were evaluated during one of their training sessions. Information about a history of consequential LBP was gathered by questionnaire. Subjects were invited to estimate the weight of three bags (a typical school bag, a sports bag with the logo of a well-known brand, and a neutral bag) containing two different loads (total weights approximately 3 and 5 kg).

RESULTS

Consequential LBP (i.e., LBP requiring medical attention and/or interfering with usual sports activities) was reported by 26.2% of them. The majority of the LBP episodes occurred ≥3 months before the tests. Overall, teenagers significantly (p ≤ 0.05) underestimated the weight of the sports bag compared with the school bag and the neutral bag. Compared with those with no LBP, subjects with a history of LBP overestimated the weight of the heavier load.

CONCLUSIONS

Our results suggest that several subjective variables significantly influence the perception of load heaviness. Until we have a better understanding of the mechanical role of the backpack weight versus the perception of its weight in the aetiology of LBP, any recommendations about the schoolbag weight limit should be viewed with caution.