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

Examining the Backpack Weight Relative to Students' Body Weight Among Urban and Rural Schoolchildren: A Cross-Sectional Study

Background Schoolbags or backpacks have been an essential part of the education system for a long time. However, a hefty backpack causes the child to arch the back excessively or bend their head and trunk forward to withstand the weight of the schoolbag. If the student carries the backpack on one shoulder, he/she bends to the opposite side to compensate for the extra weight, which may damage the shoulders and spine. Considering these factors, the main aim of this study was to investigate the percentage of backpack weight in proportion to the student's body weight regarding the new guidelines among urban and rural schoolchildren aged 12 to 15 years in Bangalore, Karnataka. Methodology In southern India, over a year, a cross-sectional study was conducted with 500 students who voluntarily participated after providing written consent. They completed a questionnaire, underwent vital and anthropometric measurements, and had their weights measured, including the weights of their backpacks. Sample bags were inspected to determine contributing weight factors and evaluate adherence to timetables. Results The average weight carried by children of all ages was 6.53 kg, averaging 13.53% of their body weight. Among males, the percentage carrying backpacks weighing over 10% of their body weight was 80.9%, while among females, it was 85.7%. Of all the males carrying bags weighing more than 10% of their body weight, 67.7% attended government schools, while 32.3% attended private schools. Among females studying in government schools, 63.6% carried backpacks weighing more than 10% of their body weight, while among those in private schools, 36.4% carried bags exceeding that weight. Conclusions The study concluded that despite regulations being implemented on backpack weight for children, a significant number still carry bags exceeding 10% of their body weight among both urban and rural school children. This could elevate pressure on neck and back muscles, leading to excessive fatigue and potential damage to the skeletal system, ultimately contributing to spinal deformities.

The Acute Effects of Schoolbag Loading on Posture and Gait Mechanics in 10- to 13-Year-Old Children: A Cohort from the North West Province

Most schoolchildren carry schoolbags, of which a substantial proportion carry loads that exceed 15% of their body mass. Although the effects of loading have been investigated to varying degrees, the status of schoolbag loading and the acute affects thereof on gait and posture have not been thoroughly investigated within the South African context. A total of 60 participants in the 10-13-year age range volunteered for the present study. Significant differences were evident for relative load carriage (χ2(3) = 14.54, p < 0.001), forefoot and heel forces (Mdiff = 17.05-34.86 N, p < 0.001), force ratios (Mdiff = 0.02, p = 0.029), and gait speed (Mdiff = -0.18 km/hr, p = 0.016), but not for any postural angles (Mdiff = -3.37-6.08 deg, all p > 0.052). Those who exceeded 15% BM were ~9 times more likely to report pain than those below 15% BM. The children in the current study carried significantly heavier relative loads (p < 0.001) compared to similarly aged children from other countries. Loading leads to acute changes in posture and gait that are likely not meaningful. However, excessive loading (>15% BM) leads to significantly higher perceptions and reporting of pain in 10-13-year-old children.

Neck and Upper Extremity Musculoskeletal Symptoms Secondary to Maladaptive Postures Caused by Cell Phones and Backpacks in School-Aged Children and Adolescents

Technology is an essential part of our lives. Nowadays, it is almost impossible to leave the house without a cell phone. Despite the wide range of benefits of cell phones and handheld electronic devices, this evolution of technology has not come without a price. The pandemic of cell phone use among children and young adolescents has led to the emergence of a set of musculoskeletal (MSK) symptoms that have not been seen before in this age group. These symptoms can range from neck and shoulder discomfort to pain, peripheral neurological symptoms of the upper extremity, and long-term complications such as disk prolapse and degenerative disk disease of the cervical spine. This clinical presentation is known as “text neck syndrome.” In addition to MSK symptoms, text neck syndrome could also include eye and ear symptoms, psychological problems, peripheral neurological symptoms, and poor academic performance. Multiple mechanisms have been discussed by which cell phone use causes MSK symptoms. Maladaptive postures, a decrease in physical activity leading to obesity, and the direct effect of electromagnetic radiation are some of the mechanisms by which long-term use of cell phones leads to the clinical presentation of text neck syndrome and its long-term consequences. The purpose of this article is to review the literature, discuss the epidemiology of cell phone use and MSK symptoms associated with its use in children and adolescents, describe its clinical presentation, explain the pathophysiology behind it, and provide preventative guidelines that can be used by this age group to allow for the continued use of these electronics without harmful effects on their posture and long-term health.

Effect of Load Carriage Lifestyle on Kinematics and Kinetics of Gait

Backpacks are commonly worn by many people for multiple purposes. This study investigated the effects of habitual wearing of backpacks on lower limb kinematics and kinetics. Fourteen participants were recruited for analysis. All participants performed four randomly assigned scenarios, including running and walking at speeds of 3.5 and 1.5 m/s, respectively, with and without load carriage. The motion analysis system and force plate were used to investigate the lower limb kinematics and kinetics. A paired sample t-test was performed for statistical measurement with a significance level of α = .05. The results indicated that active force, breaking force, impact peak, loading rate, active peak, maximum braking, hip flexion, and hip range of motion were substantially higher under load carriage conditions than under walking condition, however, time to peak was lower. Conversely, during load carriage running, active force, braking impulse, time to peak, ankle plantarflexion, and ankle range of motion were all higher than those during running. Carrying a backpack weighing 10% of the body weight induced different foot strike patterns at both speeds; during load carriage walking, the hip tended to flex more; whereas, during load carriage running, the ankle tended to flex more. In conclusion, human body seems to adopt different gait strategies during load carriage walking and running. That is, the hip strategy is used during walking, while the ankle strategy is used during running.

Assessment of the elementary school students’ schoolbag weight in the urban environment in Poland: A cross-sectional study carried out as a part of the ‘Lightweight Schoolbag’ and ‘Let’s Get the Kids Moving’ projects

BACKGROUND: Carrying a properly weighted schoolbag is an important factor in preventing the occurrence of muscular skeletal disorder in early school age children. OBJECTIVE: The purpose of this cross- sectional observational study was to examine the schoolbag weight and to determine the percentage of children were carrying overloaded schoolbag. METHODS: The study group included pupils from five primary public schools in Wrocław, Poland. Anthropometrical measurements such body weight (BW) and height were conducted on 650 children (51.1% of boys). Children’s age, gender, Cole’s Index was juxtaposed with schoolbag weight. The mean age of the examined students was 8.7±0.8 years (range 7 to 10 years). RESULTS: The mean schoolbags weight was 3.7±0.92 kg, which represented 13.0±3.8% of pupils’ BW. The percentage of pupils carry the schoolbags weighing more than 10% of their BW was 77.9%. More than a quarter of Polish children carry school backpack above 15% of their BW. The majority (96.8%) had schoolbags which may be carried on both shoulders. A significant negative correlation was observed between relative schoolbag weight and Cole’s Index (rho = –0.44, p < 0.05). CONCLUSIONS: The problem of overloaded schoolbags among elementary school children was frequent. Pupils ought to be educated in the proper packing of their school backpacks. Additionally, parents and teachers should pay attention regarding the contents carried by children in their respective schoolbags.

Establishing minimal clinically important difference for effectiveness of corrective exercises on craniovertebral and shoulder angles among students with forward head posture: a clinical trial study

BACKGROUND

Previous studies have addressed the effects of different exercises and modalities on forward head posture (FHP), but the minimal clinically important difference (MCID) of the effect of exercises on FHP remains unclear. Therefore, this study aimed to investigate the effects of selective corrective exercises (SCEs) on the craniovertebral angle (CVA) and shoulder angle (SA) in students with FHP and to establish MCID for these angles.

METHODS

In this randomized clinical trial study, a total of 103 second-grade male students with FHP were enrolled. Participants were randomly assigned to experimental and control groups. CVA and SA of participants were measured before and after the 8-week selective corrective exercise program (including strengthening and stretching exercises). The photogrammetric method was used to measure CVA and SA. MCID value was calculated for CVA and SA using the distribution method.

RESULTS

The results showed that there was a significant difference between the experimental and control groups in terms of CVA (F = 89.04, P = 0.005, Effect size = 0.47) and SA (F = 18.83, P = 0.005, Effect size = 0.16). After eight weeks of selective corrective exercises, the MCID values of CVA and SA were 1.40° and 1.34°, respectively.

CONCLUSION

This study revealed that the selective corrective exercises might lead to postural correction of students having FHP problem. Results further indicated that a corrective exercise program would be considered beneficial if it increased CVA and SA values at least 1.40 and 1.34 degrees, respectively.

Neglected problem: Influence of school bag on lumbar segment in children

BACKGROUND AND OBJECTIVES

School bag (SB) load causes significant changes in the height and symmetry of the intervertebral discs at each level of the spine from T12-L1 to L5-S1. This study aims to determine the change in the size of the lumbar segment angle at a particularly critical point L3-L4 of the spine in relation to the load of the average weight of SB in healthy male children (students) at standing and after 2-minute gait.

METHODS

47 boys, aged 12.2 ± 0.92 years, underwent photogrammetric measurements in the sagittal plane in statics and dynamics, walking on a laboratory treadmill. Measurements were repeated with the weight of SB with a constant load of 6,251 kg, which represents 13.78% of the average body weight of our sample. The lumbar angle (LA) connecting the point of the big toe, the lumbar point L3-L4 and the processus spinosus C7 was measured. In gait, LA was measured in the phases of the middle support and the initial contact of the heel.

RESULTS

T-test of paired samples was used to estimate the change in LA at standing from 4.953° and walking phases from 6.295° to 7.332° in relation to the unloaded state, and the value of the effect size (ES) indicates that the impact of SB load is significant.

CONCLUSIONS

Cumulatively, microtraumas caused by SB load significantly affect the increase in intervertebral pressure at the L3-L4 point, which is susceptible to degenerative processes and which can be the cause of lumbar syndrome (LS). Preventive measures are needed in order to lighten SB in this population and introduce up to 10% of students' body weight into the safe zone.

Effects of School-Based Educational Program on Backpack Carrying Behavior in Teenage Students

One of the most serious issues is the growing prevalence of backaches among adolescent students as a result of carrying backpacks. The purpose of this study was to examine the impact of an education program (remedial information) on the school backpack carrying habits of adolescent students. The study sample consisted of 138 adolescent students aged 12 to 16 from 4 schools who were randomly assigned to either the experimental (N = 69) or control (N = 69) groups. The experimental group was subjected to a 6-week education program consisting of 6 sessions, whereas the control group received no educational intervention. During the pre-test and 3 months after the intervention, participants completed a questionnaire. The results (healthy items) were as follows: (1) carry as little as possible, (2) carry a school backpack on both shoulders, and (3) use lockers or something similar. After a 3-month follow-up, healthy items in the experimental group improved, but no significant changes were observed in the control group. When compared to the baseline, the experimental group’s healthy backpack usage habits improved significantly at the post-test (P = .001). The current study’s findings show that school-based education interventions on backpack behaviors improve the school-bag carrying habits of adolescent students.

Text neck: An adverse postural phenomenon

BACKGROUND

The excessive use of hand-held mobile devices (HHMD) leads to a postural phenomenon known as text neck.

OBJECTIVE

The aim of this paper is to discuss the anatomical, biomechanical and muscle activation changes within the cervical and thoracic regions associated with the sustained, forward, flexed neck posture, observed with excessive usage of hand-held mobile devices. Additionally, this paper examines the relationship of gender, as well as the effects of carrying backpack loads by youth, on this forward, flexed neck posture.

METHODS

Multiple aspects of the text neck position that occur when an individual uses a HHMD are described.

RESULTS

Prolonged use of hand-held mobile devices results in adverse anatomical and biomechanical changes in the cervical and thoracic spine, muscular imbalances, and postural compensations, all of which contribute to muscular overuse and fatigue resulting in pain.

CONCLUSIONS

Physical therapists must educate their patients about proper posture while using hand-held mobile devices. Proper posture includes: holding the device close to eye level, using the device while standing or sitting and holding the device with a line of sight perpendicular to the surface of the device, using a larger screen, and texting with both hands. Also, because children are using hand held mobile devices at younger ages, parents and teachers must be educated about the dangers of prolonged use of hand-held devices.

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.

[The influence of backpack weight in school children: gait, muscle activity, posture and stability]

Hintergrund

Das tägliche Tragen eines schweren Schulrucksacks kann möglicherweise Haltungsstörungen hervorrufen, die sich auf das Gangbild und die Standstabilität der Kinder und Jugendlichen auswirken.

Ziel der Arbeit (Fragestellung)

Ziel der vorliegenden Studie war es, den Einfluss einer Rucksacklast von 4 kg auf das Gangbild und die Standstabilität bei Grundschulkindern zu analysieren.

Material und Methoden

In der prospektiven Arbeit wurde ein Kollektiv von zwölf Grundschulkindern zwischen 7 und 10 Jahren ohne neurologische oder orthopädische Probleme untersucht. Die Messungen beinhalteten eine klinische Untersuchung, eine dreidimensionale Ganganalyse mit elektromyografischen Aufzeichnungen und die Prüfung des ruhigen Stehens auf einer Kraftmessplatte.

Ergebnisse

Die Rucksacklast von durchschnittlich 15 % des Körpergewichts führte zu reduzierter Ganggeschwindigkeit, verkürzter Schrittlänge und verlängerter Doppelunterstützungsphase. Zudem kam es zu einer erhöhten Oberkörpervorneigung, Beckenkippung und Hüftbeugung. Auch die Muskelaktivität und Stabilität der Kinder wurde durch die erhöhte Traglast beeinflusst.

Diskussion

Schulrucksäcke mit einem Gewicht von 4 kg führten bei Grundschulkindern zu Änderungen von Gang, Muskelaktivität, Haltung und Standstabilität. Das Gewicht des Rucksacks verlagert den Körperschwerpunkt nach hinten und führt zur Instabilität. Dies wird beim Gehen durch eine vermehrte Oberkörpervorneigung, Beckenkippung nach vorne und vermehrte Hüftbeugung kompensiert. Die verminderte Paraspinalmuskelaktivität deutet darauf hin, dass der Rucksack passiv getragen wird. Dies könnte sich im Langzeitverlauf negativ auswirken.

The effect of backpack load position on photographic measures of craniovertebral posture in 150 asymptomatic young adults

BACKGROUND

Altering the horizontal position of the weight in a backpack will influence the magnitude of the external torque it creates but the effect on posture is unclear.

OBJECTIVE

To use photogrammetry to determine if changes in the horizontal position of a fixed backpack weight affect external measures of craniovertebral posture in 150 asymptomatic young adults.

METHODS

A backpack was attached to a steel frame with a bar protruding posteriorly. A fixed load (5% body mass) was placed at three distances along the bar -0 m, 0.20 m, and 0.40 m. Sagittal and frontal plane photogrammetry was used to measure the craniovertebral angle (CVA), upper cervical gaze angle (UCGA) and lateral head tilt angle (LHTA). A comparison was made across unloaded (no backpack) and loaded conditions.

RESULTS

There was a significant decrease in the CVA between unloaded and loaded conditions. Changes in the UCGA were small and, while significant, may not have practical importance. There were no differences in the LHTA between the conditions.

CONCLUSIONS

Changes in the horizontal position of a fixed load affect external measures of craniovertebral posture so consideration needs to be given to not only the weight of a backpack but how the weight is positioned within the backpack.

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.

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.

Musculoskeletal problems and backpack carriage among students in Nigeria

BACKGROUND

The health implication of backpack carriage among school-aged children is a topic of growing research and public health interest. Low weighing backpacks may decrease the risk of musculoskeletal discomforts (MSDs).

OBJECTIVE

To investigate MSDs and their association with backpack carriage practices among secondary school students in eastern Nigeria.

METHOD

Across-sectional study of 404 (243 females and 161 males) secondary school students aged thirteen to seventeen who were residents of Enugu State, Nigeria was conducted. The Modified Standard Nordic Musculoskeletal Questionnaire was adapted and used to collect information onstudents' demographics, musculoskeletal painand backpack carriage. Descriptive statistics (frequencies and percentages) were utilized to summarize results. Chi-square test was used to explore the association between MSD prevalence and backpack carriage practices. Data were analysed using SPSS version 20.0. Alpha level was kept at 0.05.

RESULTS

The average backpack weight carried by the students in this study was 2.49 kg. Shoulder (185, 45.8%), neck (121, 30.0%), upper back (91, 22.6%) and lower back (22, 5.5%) in that order were the body regions most affected by MSDs within the last 12 months. More females than males reported MSDs (60.5% vs 45.2%; x2 = 8.09, p = 0.04). Other students'characteristics and backpack carriage related factors were not associated with MSDs.

CONCLUSION

There is a high prevalence of MSDs among secondary school students in this study but it is not related to backpack carriage. Further research is required to identify the factors responsible for the MSDs, as well as suitable interventions to reduce its impact in this population.

PROPOSAL AND TEST-RETEST RELIABILITY OF A SCALE FOR CERVICAL, THORACIC, AND LUMBAR SPINE PAIN IN BRAZILIAN YOUNG PEOPLE

Objective:

To propose and analyze the test-retest reliability of an instrument to verify the presence and intensity of pain in the cervical, thoracic and lumbar spine in Brazilian young people.

Methods:

This reliability study enrolled a sample of 458 participants (13 to 20 years). Two groups were formed for each sex according to the range of days for the test-retest (10±3 and 28±2 days). For analysis of spinal pain, a drawing of the human body with cervical, thoracic and lumbar spine areas delimited was presented. The following question was presented: during a normal day, do you feel pain in any of these regions of your spine? If so, what is the intensity from 0 to 10 (mark on the line)? The starting point, with the number 0, corresponded to no pain, and the number 10 to severe pain. The agreement of frequency and of intensity of pain was verified by Kappa test and Bland-Altman plot, respectively.

Results:

Intraclass correlation coefficients ranged from 0.71 (confidence interval of 95% - 95%CI - 0.59-0.79) to 0.94 (95%CI 0.90-0.96). The results concerning the agreement of pain scores showed the mean differences to be close to 0, and the largest mean difference was -0.40 (95%CI -5.14-4.34). The agreement in reported pain ranged from 72.2 (Kappa 0.43; 95%CI 0.28-0.58) to 90.1% (Kappa 0.76; 95%CI 0.60-0.92).

Conclusions:

This instrument was shown to be a reliable manner to verify the pain in different regions of the spine in Brazilian young people.

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.

Examination of gait parameters during perturbed over-ground walking in children with autism spectrum disorder

BACKGROUND

Many children with Autism Spectrum Disorder (ASD) are school-aged and typically carry a backpack. It is important to understand how this task affects walking. Weighted vests (WVs) often prescribed to mitigate behavioral effects of ASD. The effects of backpack and WV walking have not been examined in children with ASD.

AIMS

To quantify differences in lower extremity mechanics in children with ASD during WV and backpack walking.

METHODS

Eight male participants completed 15 trials in three conditions: body mass, and carrying or wearing a backpack or WV with 15% added body mass. Three-dimensional kinematic data were collected and normalized to 100% of the gait cycle. The Model Statistic was utilized to test for bilateral asymmetries between the lower extremity joints at all points along the gait cycle.

RESULTS

Analysis revealed similar numbers of significant asymmetries in hip (71.0, 70.4, 60.6), knee (68.4, 71.5, 74.6), and ankle (64.1, 68.9, 68.4) for unloaded, backpack, and WV, respectively.

CONCLUSION

Participants exhibited individualized kinematic symmetry-responses to the loaded conditions compared to the unloaded condition. These findings suggest that 15% body mass backpack or WV does not affect gait symmetry in children with ASD.

The Effect of a Backpack Hip Strap on Energy Expenditure While Walking

Objective To examine the effect of backpack hip strap use on walking energy expenditure while carrying a loaded backpack. Background Previous studies have demonstrated that energy cost increases as the mass of the load carried increases. However, few investigations have focused on backpack carriage design. Methods Fifteen young, healthy, male subjects walked at a self-selected pace for 10 minutes in two backpack loading conditions: with a hip strap (strapped) and without a hip strap (nonstrapped). Oxygen consumption (VO₂), rating of perceived exertion (RPE), respiratory exchange ratio (RER), and heart rate (HR) were monitored throughout each 10-minute trial. Change scores from the 4th to 10th minute were calculated for each variable. A t test was used to evaluate the difference between conditions for each variable. Results The changes in VO₂ (-0.62 ± 0.40 vs. 0.33 ± 0.23, p = .04) and RPE (1 ± 0.25 vs. 2 ± 0.21, p < .01) from the 4th to the 10th minute were different for the strapped versus nonstrapped condition. There was no difference in the change in RER (0.04 ± 0.01 vs. 0.03 ± 0.01, p > .05) or HR (3.53 ± 0.93 vs. 4.07 ± 1.39, p > .05) for the strapped versus unstrapped condition. Conclusions Wearing a hip strap reduced the energy expenditure and perceived exertion in as little as 10 minutes of walking compared to the nonstrapped condition. Future work should consider the effect of a hip strap on these variables while hiking for extended periods. Application Wearing a hip strap may increase the comfort and reduce the energy required of wearing a backpack. This is useful information for backpack designers, military personnel, and recreational hikers.

The association between backpack use and low back pain among pre-university students: A pilot study

Background

Individuals aged 30–60 years have a high possibility of experiencing low back pain. However, children and adolescents are not exempted from this problem. This study aimed to determine the relationship between backpack usage and the frequency of low back pain in pre-university students.

Methods

A total of 101 currently enrolled pre-university students were recruited for this cross-sectional study. They answered a questionnaire about their demographic details and their frequency of backpack usage. Their backpacks were weighed for four consecutive school days. The Roland–Morris Disability Questionnaire and Body Discomfort Chart were used to rate discomfort levels.

Results

The use and weight of a backpack were not significantly associated with low back pain, as indicated by the Roland–Morris Disability Questionnaire and Body Discomfort Chart (p > 0.05).

Conclusion

This study did not find an association between the use of a backpack and low back pain in Malaysian pre-university students.

The weight of pupils' schoolbags in early school age and its influence on body posture

BACKGROUND

Postural development progresses through a series of stages (growth spurts, development of balance and coordination, postural stability) which occur when children are at school age. The reduction in the level of physical activity, increased body weight, overloaded school bags, asymmetry of the backpack straps, the method of putting on and taking off the backpacks and increased usage of electronic devices have negative side effects such as bad body posture habits.

METHODS

A prospective cohort study in the group of 155 pupils at early school age 7-9 years old has been conducted. Examinations have been conducted twice: first, at the beginning of the school year (initial examination) and second - after 10-11 months (final examination). Age, gender, BMI, weight of school bag carried to school and the length of straps have been assessed. Body posture measurement (using Adams' test), the evaluation of the plumb line deflection from the gluteal cleft, the angle values of kyphosis and lordosis (according to Dobosiewicz methodology) and the pelvis and shoulder blades position (using a ruler and pediscoliometer) have been also measured.

RESULTS

The mean weight of a school bag in the initial study was 6.3 ± 0.8 (range between 4,7 and 9 kg). A tendency to carry slightly heavier school bags was noted in boys (6.7 vs. 5.9 kg; p = 0,00001). This tendency has linearly changed with age (R = 0.68; p < 0,001). In 3.2% of all school bags of children, weights exceeded norms with regard to the weight of the pupil. The increase of torso rotation exceeding norms was observed in 35.3% of girls (mean 2.7 ± 1.2) and in 60.9% of boys (mean 2.3 ± 1.3). The increase of kyphosis angle was noted in 48.5% of girls and in 36.8% of boys. The difference of straps length had a significant influence on the increase of rotation in upper thoracic spine, thoracolumbar junction and it also had influence on the decrease of lumbar lordosis in the group of girls.

CONCLUSIONS

Differences in the weight of school bags after one school year have influenced changes in body posture abnormalities, especially in rotation parameters. Backpack straps asymmetry was noticeably stronger in the group of girls and the difference between braces may have an impact on some posturometric parameters. Lack of proper backpack lifting skills tends to create programs and training systems in this regard.

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.

Backpack-back pain complexity and the need for multifactorial safe weight recommendation

The study analysed backpack-related back pain in school children by investigating the possibility of multiple interactions among causative factors, which may be responsible for the non-conclusive findings on the issue. Using data from 444 prepubescent schoolchildren, a mixed method design combining survey, observation and direct measurement strategies was implemented. Using a multivariate structural equation modelling approach, the study investigated interactions among anthropometry, posture, backpack volume, rating and back pain constructs, with each construct made of 2-4 indicators. Additionally, regression analysis was used to determine the feasibility of considering the two additional factors of age and body mass index along with the globally accepted recommendation of a load of 10-15% of body weight. Our model demonstrated an acceptable model fit and revealed direct and indirect effects of the factors. Obese children were recommended to carry a one-third lighter load than other children. The application of systematic/multiple strategies provided an explanation for some of the issues associated with school children's backpack-related back pain.

Peso e modo de transporte do material escolar no ensino fundamental I: efeito dos anos escolares e do sexo

RESUMO O peso do material escolar e o modo de transportá-lo podem contribuir para desvios posturais e dor nas costas. Por isso, o objetivo foi verificar e comparar, entre os anos escolares e os sexos, o peso do material escolar em relação ao peso corporal e o modo de transporte do material de alunos do Ensino Fundamental I, os quais deixam os seus livros em estantes na escola. Participaram 191 escolares. O peso do material escolar e o peso corporal dos alunos foram verificados com uma balança, e o modo de transporte do material foi avaliado por meio de fotos. Observou-se que 47,7% dos alunos transportavam um peso acima do limite estabelecido (10% do peso corporal do aluno), sendo que o 1º ano transportava um menor peso do que os 2º, 3º e 5º anos, mas não houve diferença entre os sexos. Foi encontrado predomínio do uso da mochila de duas alças. Contudo, apesar de a escola já ter uma estratégia para reduzir o peso do material, quase metade dos escolares transportava um peso superior a 10% do peso corporal. Logo, outras medidas para alertar os envolvidos são necessárias.

Load distribution and postural changes in young adults when wearing a traditional backpack versus the BackTpack

Backpacks lead to poor posture due to the posterior placement of the load, which overtime may contribute to low back pain and musculoskeletal complications. This study examined postural and load distribution differences between a traditional backpack (BP) and a nontraditional backpack (BTP) in a young adult population. Using a 3D motion analysis system, 24 healthy young adults (22.5 ± 2.5 years, 12 male) completed both static stance and walking trials on a treadmill with No Load and with 15% and 25% of their body weight using the two different backpacks. There was a significant difference in trunk angle, head angle, and lower extremity joint mechanics between the backpack and load conditions during walking (p<.05). Notably, relative to the No Load condition, trunk angle decreased approximately 14° while head angle increased approximately 13° for the BP 25% state on average. In contrast, average trunk and head angle differences for the BTP 25% state were approximately 7.5° and 7°, respectively. There was also a significant difference in head angle from pre- to post-walk (p<.05) across backpacks, loads, and time. Taken together, the results indicate that the BTP more closely resembled the participants' natural stance and gait patterns as determined by the No Load condition. The more upright posture supported by the BTP may help reduce characteristics of poor posture and, ideally, help to reduce low back pain while carrying loads.

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.

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.

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.

Fatores associados à dor musculoesquelética em escolares da rede pública municipal no extremo sul do Brasil

Objetivos: identificar os fatores associados à dor musculoesquelética (DME) em escolares da rede municipal de ensino na cidade de Rio Grande, extremo sul do Brasil, entre junho e dezembro de 2010. Métodos: trata-se de um estudo seccional conduzido em uma amostra aleatória de 625 escolares entre seis e 18 anos de idade. A DME foi pesquisada utilizando o Questionário Nórdico de Sintomas Osteomusculares (QNSO) e informações demográficas, biológicas, forma de transporte do material escolar e de estilo de vida obtidas via questionário padronizado. As razões de prevalência bruta e ajustada da associação da DME com os fatores investigados foi estimada em um modelo de regressão de Poisson. Resultados: a prevalência de DME foi de 37,6%. Idade entre 11 e 18 anos (RP=1,70; IC95%=1,36- 2,11; p<0,001), sexo feminino (RP=1,47; IC95%=1,19-1,81; p<0,001) e histórico familiar de distúrbio na coluna (RP=0,78; IC95%=0,64-0,96; p=0,020) estiveram associados ao desfecho. Não praticar esportes de competição foi um fator de proteção (RP=0,65; IC95%=0,51-0,81; p<0,001). Conclusão: estes resultados confirmam a influência negativa de diferentes fatores presentes no ambiente escolar sobre a saúde dos estudantes. Considera-se como medida importante a implantação de programas de promoção da saúde nas escolas, que estimulem entre os estudantes a adoção de práticas saudáveis que minimizem os efeitos deletérios da DME.