Backpacks in children

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.

Effects of Postural Interventions on Physical and Psychological Aspects of Children in Terms of Secondary Sexual Characteristics

Children with secondary sexual characteristics who experience considerable physical, psychological, and social development are prone to physical and mental imbalances. The effects of postural intervention on physical and psychological aspects in junior high school students in terms of secondary sexual characteristics were investigated in this study. Of the 30 participants in this study, 21 (10 boys, 11 girls) with complete measurements were included. The postural intervention consisted of 1 month of direct muscle stretching for postural maintenance and breathing as well as activities to orient the spinal curvature. The participants’ body arrangement, spinal curvature, and General Health Questionnaire 30 (GHQ) scores were compared before and after the postural intervention. The intervention improved postural alignment (e.g., head−neck angle t20 = 2.33, p < 0.05, 95%CI [0.30, 5.36]) and GHQ scores (e.g., GHQ total t20 = 3.36, p < 0.01, 95%CI [0.79, 3.40]). The postural intervention improved the posture of the students as well as positively affected their mental health. This study showed that students with secondary sexual characteristics can receive physical and psychological care without the use of special facilities or techniques.

The impact of a school backpack's weight, which is carried on the back of a 7-year-old students of both sexes, on the features of body posture in the frontal plane

Background

The lifestyle of children has a significant impact on the future health of the whole society. Therefore, health education, prevention and monitoring of health determinants is important at every stage of ontogenesis. This requires a thorough knowledge of the schoolchild's environment, perceived as a wide set of stressors, including not only genetic but also epigenetic factors. One of them is the issue of the correct and abnormal body posture at school and on the way there. The goal of the study was to show the influence of the weight of the back carried container with school supplies on body posture.

Method

The research was carried out as part of a project that examined the impact of carrying weights, which are school supplies, by children on their posture. The research material consisted of data obtained from a group of 65 students (35 girls, 30 boys) aged 7 years. Body posture tests were carried out, using the projection moiré method in 4 positions: 1-habitual posture, 2-posture after 10-min of asymmetric axial load, 3-a posture after 1 min of the load removal, 4-a posture after two minutes of the load removal. Physical fitness was measured with the Sekita test. The obtained data were statistically analyzed.

Results

The significance of differences between the 1st and 2nd measurements was analyzed to determine the impact of the backpack load and the correlation with physical fitness, and to study its influence on the value of the differences in posture features. Considering the differences in the volume of posture features among boys between the 1st and 2nd measurement, the Wilcoxon’s rank test showed a statistically significant difference in the range of all analyzed variables, except for the torso bend angle to the right (KNT+), where no statistically significant change was noted. A statistically significant difference in the volume of all analyzed variables was observed among the girls.

Conclusions

Carrying school supplies on the back induces significant changes in the value of the features describing the body posture in the frontal plane. The greater weight of the container and carrying time, and intensity of physical effort is the greater the changes will be. Physical fitness has a various and sex-dependent influence on the value of changes in body posture features because of carrying school supplies. Among boys it significantly affects the asymmetry of the torso bend, shoulder height, the waist triangles height and width, whereas among girls it affects the asymmetry of the shoulders and the distance of the angles of the lower shoulder blades from the line of the spinous processes of the spine. Among boys the changes in the value of posture features are mostly influenced by endurance and speed, but strength, power and agility are of lower influence, whereas among girls only agility matters.

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.

Association between the Use of Backpack and Static Foot Posture in Schoolchildren with Static Pronated Foot Posture: A 36-Month Cohort Study

Background: Schoolchildren often spend a lot of time carrying a backpack with school equipment, which can be very heavy. The impact a backpack may have on the pronated feet of schoolchildren is unknown. Aims: The objective of this study was to evaluate the association of the backpack use on static foot posture in schoolchildren with a pronated foot posture over 36 months of follow-up. Methods: This observational longitudinal prospective study was based on a cohort of consecutive healthy schoolchildren with pronated feet from fifteen different schools in Plasencia (Spain). The following parameters were collected and measured in all children included in the study: sex, age, height, weight, body mass index, metatarsal formula, foot shape, type of shoes, and type of schoolbag (non-backpack and backpack). Static foot posture was determined by the mean of the foot posture index (FPI). The FPI was assessed again after 36 months. Results: A total of 112 participants used a backpack when going to school. Over the 36-month follow-up period, 76 schoolchildren who had a static pronated foot posture evolve a neutral foot posture. Univariate analysis showed that the schoolchildren using backpacks were at a greater risk of not developing neutral foot (odds ratio [OR]: 2.09; 95% CI: 1.08–4.09). The multivariate analysis provided similar results, where the schoolchildren using a backpack (adjusted OR [aOR]: 1.94; 95% CI: 1.02–3.82) had a significantly greater risk of not developing a neutral foot posture. Conclusions: A weak relationship was found between backpack use and schoolchildren aged from five to eleven years with static pronated feet not developing a neutral foot posture over a follow-up period of 36 months.

Physical and psychological effects of postural educational intervention for students experienced school refusal

Poor posture has been shown to decrease both visceral and respiratory/circulatory function as well as to increase neuro-musculoskeletal system stress. Improper postures of children at school and in daily life can affect their physical and psychological development. In particular, many children who refuse to go to school or who have experienced school refusal have physical and mental problems. Given that posture is closely related to one’s psychological state, modifying one’s posture can improve both physical and psychological health problems. This study examined the changes to school-refusing students’ physical and psychological condition after attending an intervention to improve their posture. The participants were 65 high school students who have experienced school refusal and were attending a program to modify their posture for 2 months. Their posture and psychological states were recorded both pre- and post-intervention with the following measurements: postural alignment and spinal curve according to a sagittal plane, the General Health Questionnaire 30 (GHQ), and the Subjective Adjustment Scale (SAS). Post-intervention, most of the participants saw improvement in their postural alignment (e.g., trunk inclination in standing position, P < 0.001, 95%CI [2.00, 4.00]). Participants with improved standing posture post-intervention had higher SAS scores (e.g., feeling of acceptance and trust, P < 0.05, 95%CI [−3.00, −0.00]). We found that easy-to-implement postural interventions have a positive effect on students’ mental health. Furthermore, it was suggested that their adjustment to school would also improve as their posture improved. The contribution of this study shows that it is possible to care for the physical and mental health of students without using special facilities and techniques. It is hoped that the findings of this study will lead to an improved adjustment to both school or novel environments, as well as prevent health-based school refusal.

Effects of School Backpacks on Spine Biomechanics During Daily Activities: A Narrative Review of Literature

OBJECTIVE

The purpose of this narrative review is to summarize the effects of carrying school backpacks on spine and low-back biomechanics as a risk factor for low back pain in young individuals.

BACKGROUND

Backpacks constitute a considerable daily load for schoolchildren. Consistently, a large number of children attribute their low back pain experience to backpack use.

METHOD

A literature search was conducted using a combination of keywords related to the impact of carrying backpacks on lower back biomechanics. The references of each identified study were further investigated to identify additional studies.

RESULTS

Twenty-two studies met inclusion criteria. A total of 1,159 people aged 7 to 27 years were included in the studies. The added load of a backpack and the changes in spinal posture when carrying a backpack impose considerable demand on internal tissues and likely result in considerable spinal loads. The findings included results related to the effects of backpack weight and position on trunk kinematics and spine posture as well as trunk muscle activity during upright standing, walking, and ascending and descending stairs.

CONCLUSION

Backpack-induced changes in trunk kinematics for a given activity reflect alterations in mechanical demand of the activity on the lower back that should be balanced internally by the active and passive responses of lower back tissues. Although the reported alterations in trunk muscle activities and lumbar posture are indications of changes in the active and passive response of the lower back tissues, the resultant effects on spinal load, that is, an important causal factor for low back pain, remains to be investigated in the future. A knowledge of backpack-induced changes in spinal loads can inform design of interventions aimed at reduction of spinal load via improved backpack design or limitation on carrying duration.

APPLICATION

This narrative review is intended to serve as an educational article for students and trainees in ergonomics and occupational biomechanics.

School bag weight and the occurrence of back pain among elementary school children

Background: Children in primary schools use school bags to carry study material, although the heavy bags are often associated with musculoskeletal problems, especially back pain. This practice requires strength, which significantly changes the body posture and walking pattern, subsequently leading to the incidence of back pain as a side effect. The aim of this study, therefore, is to analyze the differences in bag loads between elementary school children in urban and suburban area, and also analyze the relationship with the occurrence of back pain.

Design and methods: This was a cross sectional study, which used stratified random sampling to choose 2 elementary schools each representing the urban and suburban areas. Furthermore, a total sample of 164 students were selected, whose school bag weight were measured for 5 consecutive days, particularly in the morning on respondents arrival at school. Moreover, the occurrence of back pain was evaluated using a modified Nordic map, and data analysis required the use of independent sample analysis t test and χ² test.

Results: The results showed the presence of highly significant differences in the school bags weight of respondents in the urban and suburban areas, as well as between schools using the 2013 curriculum and otherwise.

Conclusions: In conclusion, there is a correlation between the weight measured and the occurrence of back pain, hence the 2013 curriculum is recommended to be adopted by all elementary schools. Also, the use of lockers to store items used at school repeatedly by children is also highly encouraged.

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.

The Impact of Backpack Loads on School Children: A Critical Narrative Review

Background: Backpack loads of school students during school days have been suggested to range from 10% to as high as 25% of their body weight and may have a negative impact on their body. The aim of this review was to identify and review studies that have examined impacts of contemporary backpack loads on school children. Methods: A systematic search was conducted of the literature using key search terms. After relevant studies published in recent years were selected using strict inclusion and exclusion criteria, the studies were critically appraised and relevant data were extracted and tabulated prior to conducting a critical narrative synthesis of findings. Results: Twenty-one studies were included, ranging in methodological quality from poor to good (critical appraisal scores 22% to 77%). Students carried on average over 15% of their own body weight, which caused biomechanical and physiological adaptations that could increase musculoskeletal injury risk, fatigue, redness, swelling and discomfort. Conclusion: Considering the limited methodological quality and variations in foci across studies, further research is needed to elucidate: (1) the loads students carry around on a school day in their school backpacks and; (2) the biomechanical, physiological and physical effects of load carriage on students.

The effects of backpack type on lumbo-pelvic coordination during trunk bending and return tasks

Backpacks with ergonomic features are recommended to mitigate the risk of developing low back pain due to carrying a heavy school backpack. A repeated measure study was conducted on 40 college-age students to investigate the immediate changes in magnitude and timing aspects of lumbo-pelvic coordination when carrying an ergonomically modified vs. a normal backpack relative to no backpack condition during trunk forward bending and backward return tasks. We found a smaller reduction in the thoracic range of rotation, an increase vs. a decrease in pelvic range of rotation and a larger reduction in lumbar flexion for a modified vs. a normal backpack. Furthermore, during the forward bending, a less in-phase motion for the modified backpack was observed. Our results suggest that participants have likely experienced larger spinal loads with the modified backpack; a conclusion that should be investigated in future to determine whether ergonomic backpacks can reduce the risk of low back pain in children. Practitioner summary: Research participants performed trunk bending and return closer to their habitual way under modified versus normal school backpack. From an equilibrium point of view, therefore, individuals are likely experiencing larger spinal loads during activities of daily living with a modified backpack. However, such a conclusion may change when considering stability requirements.

Backpack weight and back pain reduction: effect of an intervention in adolescents

BACKGROUND

To assess if an educational intervention is effective to reduce backpack weight and back pain in schoolchildren.

METHODS

We designed an intervention study in schoolchildren aged between 12 and 16 years aimed to reduce the weight of backpacks and back pain. The intervention was multifaceted, including an educational intervention with practical examples, advising on performing sports, postural habits, leaflets, stickers, and so on. The comparison group did not receive any intervention.

RESULTS

A total of 1668 schoolchildren took part in the study. We observed a high prevalence of carrying heavy backpacks, with 66-80% of schoolchildren carrying backpacks surpassing 10% of their body weight. Back pain prevalence was 30%. We observed that the intervention was significant in reducing the backpack weight in first-year schoolchildren but not in second-year. The intervention was also significant in reducing back pain in third-year schoolchildren but only in girls.

CONCLUSION

This study shows that an inexpensive intervention directed to reduce the backpack weight and back pain might have a positive effect in schoolchildren.

Ergonomics evaluation of school bags in Tehran female primary school children

BACKGROUND

More than 90% of the elementary school students in the world and most of the Iranian students use backpacks. Heavy school bags, failure to apply ergonomics standards in student's backpacks, and also mismatch between anthropometrics dimensions and schoolbag size are important issues for children's health.

OBJECTIVE

The purpose of this study was to gather baseline information on the average weight carried by female primary students. It also aimed to evaluate ergonomics standards for student backpacks.

METHODS

A cross-sectional study was conducted on 212 Iranian girl students aged 6- 11 years. Body weight and bag weight were measured with electronic scales and body mass index calculated with WHO software 2007. A questionnaire was constructed to gather information about the backpacks. Body dimensions were measured with VICON motion Analyze system (460). Ergonomics factors were recorded using a checklist.

RESULTS

80.8% of the students used a backpack at a higher weight than recommended by the standards of 10% of body weight. The most common type of schoolbag used was double strap packs (92.5%). The majority of the students carried packs on their backs; however, most of them did not make any adjustments (79.8%). The results have shown a mismatch between the anthropometric measures and the student's backpack dimensions.

CONCLUSIONS

Parents, students and school staff should be informed about these critical issues as well as suitable controls should be implemented in buying and using the bags.

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.

Effect of variable backpack load and strap option on the pulmonary function of children: A simulation using treadmill walking

BACKGROUND

The restrictive effect of backpack loads on chest expansion has been widely reported but little is known whether pulmonary function in children is affected by the placement of the straps of the backpack.

OBJECTIVE

To determine the effects of strap configuration and backpack loads on pulmonary function among school age children.

METHODS

Eighteen children (mean age of 12±1.68 years) participated in this study. Pulmonary functionwas assessed using spirometryat baseline and during five test conditions. Two strap configurations were compared: double straps with the backpack worn midline on the back with one strap over each shoulder and single strap with the backpack worn laterally with one strap over the shoulder.

RESULTS

A marginal increase was shown in all measures of pulmonary function during standing and walking, and as the backpack weight increased. However, all the marginal changes in pulmonary function tests across different weights and strap patterns were not statistically significant.

CONCLUSION

Variable backpack loading and strap options appear to influence changes to the pulmonary function of children. Although the observed changes are marginal, it could not be determined if they have a long term effect. Further investigations of larger sample size are required to inform practice.

EPIDEMIOLOGY OF MUSCULOSKELETAL DISORDERS IN PRIMARY SCHOOL CHILDREN IN BOSNIA AND HERZEGOVINA

Introduction:

Musculoskeletal disorders represent a significant problem of modern society which are more pronounced in young people and school children. Etiology of these disorders is found in inadequate ergonomic conditions, too heavy school bag, school furniture inadequate to age, poor posture, sedentary lifestyle, reduction of physical activity and lack of exercise.

Material and methods:

This cross-sectional study included 1315 pupils aged 8- 12 years. As a method was used “cluster sample” in the selection of subjects. The survey was conducted by questionnaire containing information on the demographic and individual characteristics of participants (age, gender, class), the manner and style of life and the performance of school tasks, followed by standardized Nordic questionnaire. The following parameters were measured: body height and weight for each student, and the weight of full and empty school bag that students that day brought to class.

Results:

The incidence of musculoskeletal pain regardless of localization was 48%. There is a statistically significant correlation between acute pain in the right shoulder and total weight of school bags, duration of caring the bag in school and time of wearing bag from school to home but not with the manner in which school bag was carried. Acute pain in the right shoulder and acute neck pain were significantly associated with the duration of sitting in school or in front of a computer at home. Acute pain in the shoulder negatively correlated with BMI percentile value of the respondents. Acute pain in the neck is also significantly associated with the weight of a full school bags, as well as time spent sitting at home doing homework. Acute back pain is statistically significantly correlated with the weight of school bags and duration of sitting periods in school.

Conclusion:

The prevalence of musculoskeletal pain, particularly chronic pain in school children aged 8-12 years is high. Weight of school bags, manner in which the bag is carried to and from school, duration of carrying bags, time spent sitting in the school and in front of the computer, duration of sitting and posture during homework, body mass index are ergonomic reasons for the development of musculoskeletal pain.

Evaluation and Diagnosis of Back Pain in Children and Adolescents

Although traditionally it has been accepted that back pain in young children and adolescents most often has an organic etiology, nonorganic back pain in this population is becoming more common. The most common identifiable clinical entities responsible for such pain are spondylolysis, spondylolisthesis, Scheuermann kyphosis, overuse syndromes, disk herniation, apophyseal ring fracture, spondylodiscitis, vertebral osteomyelitis, and neoplasm. Appropriate clinical workup leads to earlier diagnosis and management of back pain and avoids unnecessary cost. Knowledge of the most common diagnoses associated with back pain in children and adolescents and the use of a systematic method to select the appropriate diagnostic tests can help the clinician to minimize costs and maximize the likelihood of making the correct diagnosis and providing appropriate treatment.

Influence of the Weight of a School Backpack on Spinal Curvature in the Sagittal Plane of Seven-Year-Old Children

The aim of the paper was to determine a correlation between the weight of a child's backpack, their body weight, and certain features of their body posture. Material and Methods. The study group consisted of 109 children, all aged seven years. The parameters of body posture were determined using the Zebris Ultrasonic System. Results. The number of children carrying a school backpack in accordance with recommendations was 44 subjects (40.37%). Statistically significant changes were found in the total length of the spine (Z = 2.223, p = 0.026) and between backpack weight and changes in the following parameters: the total length of the spine (r_s = −0.3999, p = 0.017), the length and the angle of the lumbar lordosis (r_s = −0.3352, p = 0.049), the angle of the lumbar lordosis (r_s = −0.5065, p = 0.002), and the sacral angle (r_s = −0.4279, p = 0.010). Conclusions. Wearing a backpack heavier than 10% of one's body weight can cause shallowing of the lumbar lordosis and a tendency towards a vertical position of the sacrum. Monitoring the weight of children's school backpacks and enabling them to leave books and notebooks at school would probably be beneficial in reducing the daily burden put on children's spines.

Effects of carrying a backpack in an asymmetrical manner on the asymmetries of the trunk and parameters defining lateral flexion of the spine

OBJECTIVE

The aim of this study was to examine changes in the body posture parameters defining asymmetry of the trunk and lateral flexion of the spine in children while carrying a backpack weighing 10% of a child's weight.

BACKGROUND

Carrying a backpack may negatively affect the posture of schoolchildren and contribute to spinal pain.

METHOD

The study involved 162 primary school students ages 11 to 13 years. The parameters describing body posture were assessed with a backpack carried on the right or left shoulder as well as without a load. To assess the predefined parameters, we used the CQ Elektronik System, employing the photogrammetric method.

RESULTS

Trunk inclination shifted significantly in the opposite direction to the shoulder the backpack was carried on, and an increase in shoulder asymmetry was also found. We also observed a more pronounced right-side lateral flexion of the spine when the backpack was carried on the right shoulder and an analogous relationship for the left side.

CONCLUSION

The results of this study show that carrying a backpack in an asymmetrical manner negatively affects spine, even if the backpack weight constitutes 10% of the child's weight, which has been previously recommended as a safe load for a child's shoulders.

APPLICATION

We suggest that the issue of safe backpack weight be reassessed and that students be taught basic ergonomic principles on how to carry loads. Changes to the management pattern of carrying textbooks to and from school also should be considered.

Altered disc compression in children with idiopathic low back pain: an upright magnetic resonance imaging backpack study

STUDY DESIGN

This study is a repeated measures design to measure the lumbar spine's response to common backpack loads in children with idiopathic low back pain (ILBP) using upright magnetic resonance imaging (MRI).

OBJECTIVE

The purpose of this study is to analyze the lumbar spine's response to backpack loads with upright MRI in children with ILBP to compare their results with previously published normal child data under the same conditions. We hypothesize that typical backpack loads will have a different effect on the lumbar spine of normal children and children with ILBP.

SUMMARY OF BACKGROUND DATA

Research in normal children shows that backpack loads compress the lumbar intervertebral discs (IVDs), increase lumbar coronal deformity, and increase pain.

METHODS

Fifteen pediatric and adolescent patients with ILBP were selected. Patients were excluded if a spinal deformity, an underlying pathology, or known injury was identified. A 0.6-T upright MRI scanner imaged the subjects while in supine and standing positions wearing 0-kg, 4-kg, and 8-kg backpacks. IVD height, lumbar lordosis, lumbar coronal deformity, and pain score were recorded after each condition and compared using analysis of variances. We compared the above-mentioned variables between ILBP and normal subjects using generalized least squares models.

RESULTS

The cohort's mean age was 13 ± 3 years. The 4-kg and 8-kg backpacks only compressed the L5-S1 IVD relative to upright with no load. Subjects experienced increasing pain with increasing load. Load had no effect on lumbar lordosis or lumbar coronal deformity. Compared with normal children, children with ILBP experience significantly less disc compression at T12-L1 to L4-L5, less lumbar lordosis, and more pain with increasing load.

CONCLUSION

In children with ILBP, increasing backpack load compresses only the L5-S1 IVD. Compared with normal children, children with ILBP experience less lumbar IVD compression, less lumbar lordosis, and more pain due to increasing load suggesting altered mechanisms for load tolerance in children with ILBP.

LEVEL OF EVIDENCE

3.

Postural compensations and subjective complaints due to backpack loads and wear time in schoolchildren

PURPOSE

This study investigated the effects of carrying weighted backpacks of up to 20% of body weight on the posture and pain complaints of elementary-school children.

METHODS

Craniovertebral, forward trunk lean and pelvic tilt angles were measured from sagittal photographs of 62 children (8-11 years old) before and after walking while carrying backpacks containing 10%, 15%, or 20% of body weight. Pain severity after a 6-minute walk with the loaded backpack was recorded. Subjective complaints of pain were assessed using a visual analog scale after walking.

RESULTS

Repeated-measures ANOVA revealed statistically significant differences in postural angles and increased complaints of pain after walking with increased backpack loads.

CONCLUSION

These results indicate that typical backpack loads create worsening postural changes due to backpack loads and time spent carrying those loads, putting children at increased risk for injury and pain, the latter of which is a strong predictor for back pain in adulthood.

Awareness of Parents about Characteristics of a Healthy School Backpack

BACKGROUND

The issue of knowledge on school backpacks among parents has received little attention. The objectives of this study were to assess school backpack carriage and its consistency with parents' knowledge about children friendly school backpacks.

METHODS

This was a randomized cross-sectional study. Totally 307 elementary school children and 250 parents were recruited to assess parental knowledge about standard school backpacks in 2010. Data collection were carried out on an unscheduled day in order to, children and their par¬ents prepared school backpacks based on their own previous habits and behaviors. All statistical analyses were performed using version 16.0 of the statistical software package SPSS Results: Approximately, 132 (51.6%) of the parents were not aware of the recommended weight limit for carrying school backpacks and 144 (56.3%) were not aware that the size of the backpack must be proportionate to the upper back region. Significant difference was found for the mean score of awareness of a safe and standard school backpack between fathers and mothers: fathers had more knowledge about school backpack carriages in comparison with mothers (P<0.001).

CONCLUSION

Children, parents and teachers should be educated about the characteristics of a standard backpack, different strategies. Parents are the best advocates for safety promotion and should represent the group most likely to help to significantly reduce backpack related injuries among school children by selecting safe school backpacks, supervising school backpack carrying and checking backpack weights.

Postural assessment of lumbar lordosis and pelvic alignment angles in adolescent users and nonusers of high-heeled shoes

OBJECTIVE

The aims of this study were (1) to analyze the influence of wearing high-heeled shoes on lumbar lordosis and pelvic inclinations among adolescents aged between 13 and 20 years were users and nonusers of high-heeled shoes and (2) to correlate these postural angles with age.

METHODS

Fifty adolescents from the nonuser group (NUG) of high-heeled shoes and 50 from the user group (UG) were evaluated. Postural assessments were obtained by photogrammetry under 2 conditions-barefoot and with high-heeled shoes-and analyzed using the evaluation postural software. The measured angles included lumbar lordosis and the horizontal alignment of the pelvis. Descriptive analyses were carried out, with a significance level of 5%.

RESULTS

With high-heeled use, the NUG demonstrated rectification of the lumbar spine and pelvic retroversion, whereas the UG demonstrated hyperlordosis and pelvic anteversion. When barefoot, smaller lumbar lordosis angles for both groups were observed. However, the pelvic angles were lower for the UG group and higher for the NUG. The studied angles showed high reliabilities. Age was correlated with lumbar lordosis angles for the NUG in the barefoot condition and with pelvic alignments in both conditions for the UG.

CONCLUSION

For the subjects in this study, the use of high-heeled shoes is correlated with increased lumbar lordosis and pelvic anteversions. Lumbar lordosis angles are correlated with age for the NUG when barefoot.

The effect of school bag design and load on spinal posture during stair use by children

Thirteen male children ascending and descending stairs with loads that equalled 0%, 10%, 15% and 20% of their body weight were the subject of our research: the boys were wearing an asymmetrical single-strap athletic bag or a symmetrical double-strap backpack during our experiments with them. The maximum spinal tilt to the loading side and to the support side, and the range of spinal motions, were obtained by using a motion analysis system. Our results showed that symmetry of spinal posture was observed both when they ascended staircase with all loads and descended in a backpack. When carrying an athletic bag with 15% and 20% of their body weight while ascending the staircase, the lateral spinal tilt to the supporting side was significantly increased. We concluded that a symmetrical backpack with a load not exceeding 20% or an asymmetrical single-strap athletic bag with a load not exceeding 10% should be recommended for school children in order to promote safer staircase use. STATEMENT OF RELEVANCE: Children carrying heavy school bags may develop spinal problems. This study suggested that when they are using stairs, a symmetrical backpack with a load within 20% body weight is acceptable for them. When they are carrying an asymmetrical single-strap athletic bag, the bag's weight should not exceed 10% of the body weight in order to avoid excessive spinal tilt.

The effects of age and gender on the weight and use of schoolbags

PURPOSE

To examine age and gender differences in schoolbag use and to compare findings in Greece with those of other countries.

METHOD

Schoolbag weight and carrying characteristics were assessed in 703 boys and girls aged 6 to 14 years.

RESULTS

Multinomial logistic regression models showed that younger students (6-8 years) were almost 5 more times more likely to carry heavier schoolbags than older students (p < 0.05). Similarly, more girls than boys carried heavier bags, and girls were twice more likely to experience fatigue symptoms when carrying schoolbags compared with boys (p < 0.05). The mean schoolbag weight was 12.4% of the student's body weight and moderately heavier than that reported for other countries.

CONCLUSIONS

Younger children are in greater need for education about schoolbag weight compared with older ones. There is also evidence that girls might experience more problems when carrying their schoolbag compared with boys.

The effect of backpacks on the lumbar spine in children: a standing magnetic resonance imaging study

STUDY DESIGN

This study is a repeated measures design to measure the lumbar spine response to typical school backpack loads in healthy children. The lumbar spine in this setting was measured for the first time by an upright magnetic resonance imaging (MRI) scanner.

OBJECTIVE

The purpose of this study is to measure the lumbar spine response to typical school backpack loads in healthy children. We hypothesize that backpack loads significantly increase disc compression and lumbar curvature.

SUMMARY OF BACKGROUND DATA

Children commonly carry school backpacks of 10% to 22% bodyweight. Despite growing concern among parents about safety, there are no imaging studies which describe the effect of backpack loads on the spine in children.

METHODS

Three boys and 5 girls, age 11 +/- 2 years (mean +/- SD) underwent T2 weighted sagittal and coronal MRI scans of the lumbar spine while standing. Scans were repeated with 4, 8, and 12 kg backpack loads, which represented approximately 10%, 20%, and 30% body weight for our sample. Main outcome measures were disc compression, defined as post- minus preloading disc height, and lumbar asymmetry, defined as the coronal Cobb angle between the superior endplates of S1 and L1.

RESULTS

Increasing backpack loads significantly compressed lumbar disc heights measured in the midline sagittal plane (P < 0.05, repeated-measures analysis of variance [ANOVA]). Lumbar asymmetry was: 2.23 degrees +/- 1.07 degrees standing, 5.46 degrees +/- 2.50 degrees with 4 kg, 9.18 degrees +/- 2.25 degrees with 8 kg, and 5.68 degrees +/- 1.76 degrees with 12 kg (mean +/- SE). Backpack loads significantly increased lumbar asymmetry (P < 0.03, one-way ANOVA). Four of the 8 subjects had Cobb angles greater than 10 degrees during 8-kg backpack loads. Using a visual-analogue scale to rate their pain (0-no pain, 10-worst pain imaginable), subjects reported significant increases in back pain associated with backpack loads of 4, 8, and 12 kg (P < 0.001, 1-way ANOVA).

CONCLUSION

Backpack loads are responsible for a significant amount of back pain in children, which in part, may be due to changes in lumbar disc height or curvature. This is the first upright MRI study to document reduced disc height and greater lumbar asymmetry for common backpack loads in children.

Effects of sex and mode of carrying schoolbags on ground reaction forces and temporal characteristics of gait

The aim of this study was to examine the effects of different modes of carrying schoolbags on children. Ten girls and eight boys walked without a bag (NO-BAG), with a bag placed low at the back (LBACK), with a back placed high at the back (HBACK) and carrying the bag using the handle (HANDBAG). Ground reaction forces and temporal characteristics were recorded. When carrying a schoolbag, children walked with shorter strides, at lower speeds, with higher double support phase and increased vertical ground reaction forces compared with the NO-BAG condition (P<0.01). Compared with normal walking biomechanics, the HANDBAG condition showed the highest alterations, whereas the LBACK the least. Carrying the schoolbag by the handle has the largest effect on gait characteristics. Wearing backpacks by adjusting the shoulder straps to a loose position may reduce schoolbag effects.

Spinal postural alignment variance according to sex and age in 7- and 8-year-old children

PURPOSE

Children's postural alignment undergoes many adjustments due to the changes in body proportions during the stages of growth. The objective of this study was to quantitatively characterize and analyze spinal postural standards in 7- and 8-year-old children to verify which of the differences found were correlated to age and sex.

METHODS

Two hundred thirty public school students (Amparo, São Paulo, Brazil) aged 7 to 8 years were divided into groups according to postural alignment, which were further subdivided by sex and age, for comparison. Digital photos of upright subjects were analyzed to evaluate posture. Lumbar and thoracic curvature, pelvic inclination, head posture, and lateral spine deviation were measured using CorelDraw (Ottawa, Canada) software guidelines and bone landmarks. Descriptive statistics and analysis of variance data analysis were utilized to verify differences among the groups. This was a cross-sectional, descriptive study.

RESULTS

Mean values for the variables analyzed were calculated. For lumbar lordosis, 7-year-old boys showed 38.49 degrees +/- 15.32 degrees in comparison to all other groups (42.29 degrees +/- 7.13 degrees ). For thoracic kyphosis, the 7-year-old children presented 28.07 degrees +/- 7.73 degrees , and the 8-year-olds 30.32 degrees +/- 7.73 degrees . Pelvic inclination presented a mean value of 15.82 degrees +/- 5.46 degrees and single lateral spine deviation mean value of 3.48 degrees +/- 2.12 degrees .

CONCLUSION

For the sample studied, differences based on sex and age were found for some of the body segments analyzed. The values found in this study may contribute to improved physiotherapeutic treatment when associated with other aspects of the clinical assessment and symptomatology.

Evaluation of the effect of backpack load and position during standing and walking using biomechanical, physiological and subjective measures

Recommendations on backpack loading advice restricting the load to 10% of body weight and carrying the load high on the spine. The effects of increasing load (0%-5%-10%-15% of body weight) and changing the placement of the load on the spine, thoracic vs. lumbar placement, during standing and gait were analysed in 20 college-aged students by studying physiological, biomechanical and subjective data. Significant changes were: (1) increased thorax flexion; (2) reduced activity of M. erector spinae vs. increased activation of abdominals; (3) increased heart rate and Borg scores for the heaviest loads. A trend towards increased spinal flexion, reduced pelvic anteversion and rectus abdominis muscle activity was observed for the lumbar placement. The subjective scores indicate a preference for the lumbar placement. These findings suggest that carrying loads of 10% of body weight and above should be avoided, since these loads induce significant changes in electromyography, kinematics and subjective scores. Conclusions on the benefits of the thoracic placement for backpack loads could not be drawn based on the parameter set studied.

Barriers to and Facilitators of Walking and Bicycling to School: Formative Results From the Non-Motorized Travel Study

Barriers to and facilitators of walking and bicycling to school were explored through 12 focus groups made up of fourth- and fifth-grade students and their parents who lived near their respective schools. The barriers and facilitators reported by parents and children generally fell into one of three categories: intrapersonal and interpersonal characteristics of parents and children, environmental characteristics of the neighborhood, and environmental and policy characteristics of the school. Findings indicate that a supportive environment is a necessary but insufficient condition to increase walking and biking to school. Initiatives to increase active school travel may need to include multiple levels of intervention to be effective.

Changes in gait kinematics and posture with the use of a front pack

The objective of this study was to determine if posture during gait can be affected by position of the load. It was hypothesized that the front pack would result in postural changes in the gait cycle, compared to a similarly loaded backpack. Thirteen healthy adults, free of any injury, volunteered to participate in this study. Two dimensional video data were collected at 50 Hz using a MacReflex video system. A backpack and a front pack were compared using loads of 10 and 15% of body weight. Markers were placed on the ear, acromion, greater trochanter and lateral joint line of the knee, lateral malleolus and fifth metatarsophalangeal joint. Data were collected while the participants walked at 0.75 stride/s. The data were used to calculate joint angles and displacements during each gait cycle. There was a significant difference noted in angles of the hip flexion, with the backpack condition demonstrating a greater flexion in each stride than either the control or front pack. Both backpack and front pack conditions demonstrated a significant change in neck motion compared to the control condition. The results of the position analysis over time also revealed an increase in the forward head position when participants were wearing the backpack compared to either the control or the front pack condition. It was concluded that the use of a front pack results in a more upright posture in gait, when compared to a backpack carrying the same load.

Bone scan as a screening tool in children and adolescents with back pain

Retrospective review of 142 patients from 2 teaching hospitals, investigated for persistent backache. The inclusion criteria were to be up to 18 years, to have no known associated diseases, and to have had a bone scan as a part of their work up. Other tests were also used to reach the final diagnosis. The utility of the bone scan to detect underlying pathology was assessed. On the whole, 75 patients were found to have pathology while only 52 children had a positive bone scan. We also looked for associated findings that could indicate the presence of pathology. The age of the patients, the duration of symptoms, and the presence of night pain seemed to be irrelevant on predicting underlying pathology. The sensitivity of the bone scan was low, 0.613 (95% CI: 0.549-0.654), although it proved to be highly specific, 0.91 (95% CI: 0.83-0.95). A careful analysis of the data and the different diagnosis suggests that Technetium bone scan still holds a place in the study of these patients; however, there is a big concern by the fact that some primary malignancies went undetected on the scan.

The effect of backpack load on the gait of normal adolescent girls

Concerns regarding the effects of load carriage have led to recommendations that backpacks be limited to 10?-?15% of body weight, based on significant changes in physical performance. However, gait responses to backpack loads are not entirely consistent and there is a particular lack of data regarding load-bearing gait in adolescent females. Gait patterns of 22 normal adolescent girls were recorded at backpack loads of 0, 7.5, 10.0, 12.5 and 15.0% body weight. Temporal-distance, ground reaction force and joint kinematic, moment and power parameters were analysed by repeated measures ANOVA with factors of backpack load and side (left or right). Walking speed and cadence decreased significantly with increasing backpack load, while double support time increased. Kinematic changes were most marked at the proximal joints, with a decreased pelvic motion but a significant increase in the hip sagittal plane motion. Increased moments and power at the hip, knee and ankle showed increasing demand with backpack load. Parameters showed different responses to increasing load, and those that suggested a critical load indicated this to be approximately 10% body weight. While this may be due to a change in gait due to increased demand, further work is required to verify this and also to examine the cumulative effects of backpack load on the musculoskeletal system, which may be more appropriate in determining recommended load limits.

Backpacks, back pain, sagittal spinal curves and trunk alignment in adolescents: a logistic and multinomial logistic analysis

STUDY DESIGN

Cross-sectional study using logistic and multinomial logistic analysis.

OBJECTIVES

To investigate the influence of backpack carrying on spinal profile shoulder and trunk.

SUMMARY OF BACKGROUND DATA

No similar investigations.

METHODS

A randomly selected sample of 1263 students aged 12-18 years were asked for dorsal (DP) and low back pain (LBP) during the school period and holidays. Debrunner's Kyphometer and Scoliometer were used to measure craniocervical angle (CCA), thoracic kyphosis, lumbar lordosis, and shoulder shift (BL). Upper trunk shift from plumbline were recorded.

RESULTS

Girls suffer from DP more often and of much more intensity pain than boys in school period and in holidays. Backpack carrying decreased CCA and changed shoulder and upper trunk shift. Asymmetrically backpack carrying increased DP and LBP. BL-shift increased DP. DP and LBP increased with coronal trunk shift. Sagittal trunk shift increased LBP. Asymmetrically carrying of backpacks increased back pain and shoulder shift in holidays. Coronal trunk shift while carrying backpacks asymmetrically increased back pain in holidays. Asymmetric backpack carrying is associated with high intensity pain. Frontal trunk shift is associated with high intensity pain.

CONCLUSION

Backpack carrying, particularly asymmetrically, results in shift of upper trunk and shoulder and cervical lordosis, which furthermore seem to increase back pain in school period and holidays. Symmetric backpack carrying is recommended.

Low back pain prevention's effects in schoolchildren. What is the evidence?

Given the high prevalence rates of back pain, as early as in childhood, there has been a call for early preventive interventions. To determine which interventions are used to prevent back problems in schoolchildren, as well as what the evidence is for their utility, the literature was searched to locate all investigations that used subjects under the age of 18 and not seeking treatment. Included investigations were specifically designed as an intervention for low back pain (LBP) prevention. Additionally, a literature search was performed for modifiable risk factors for LBP in schoolchildren. The literature-update search was performed within the scope of the "COST Action B13" of the European Commission, approved for the development of European guidelines for the management of LBP. It was concluded that intervention studies in schoolchildren focusing on back-pain prevention are promising but too limited to formulate evidence-based guidelines. On the other hand, since the literature shows that back-pain reports about schoolchildren are mainly associated with psychosocial factors, the scope for LBP prevention in schoolchildren may be limited. However, schoolchildren are receptive to back-care-related knowledge and postural habits, which may play a preventive role for back pain in adulthood. Further studies with a follow-up into adulthood are needed to evaluate the long-term effect of early interventions and the possible detrimental effect of spinal loading at young age.

Cartable et pathologie rachidienne

Back pain has become a real public health concern both for adults and children. In general, patients complain of moderate pain. While the topic was long ignored by the scientific community, the number of publications has increased over the last three Years. We reviewed the literature to separate real evidence from speculations. Recognized risk factors for spinal pain are: female gender, poor general status, family history of back pain, particular psychological patterns, time spent sitting watching television, history of spinal trauma, intense physical activity, practicing competition sports, and age (more frequent in adolescents than children). Several recent papers have drawn attention to the role of the weight of the school backpack in children, particularly when its weight exceeds 20% of the child's body weight. Many children carry heavy backpacks which for some may weigh 30% to 40% of their body weight. Several groups have estimated that the maximum should be 10% of the body weight. It appears that time spent carrying the backpack as well as its weight is an important factor favoring back pain. Backpacks can injury the head or face, as well as the hands, the elbow, the wrist, the shoulder, the foot and the ankle. Back trauma is observed as the sixth most common injury. The 'weak point' is the shoulder and not the back. A poorly positioned backpack can modify posture and gait. Carrying the backpack with two shoulder straps affects posture and gait less than carrying it on one shoulder. The posture of the spine changes when the weight of the backpack increases. This is probably one of the reasons why many parents who consult believe that there is a relationship between the weight of the backpack and scoliosis or kyphosis, observed in many of their children. It is proven that adolescents who suffer from back pain will probably have chronic back pain as adults, but there is not evidence to our knowledge demonstrating a relationship between the development of spinal deviation and the weight of the backpack. Recent studies have been conducted to design backpacks allowing a better weight distribution and comfort. This type of backpack appears to have a limited benefit. Furthermore, the question of mode must not be ignored for children and adolescents. Backpacks with one sack in front and one in back certainly provide better weight distribution but are they acceptable for children and adolescents?