The associations between adolescent head-on-neck posture, backpack weight, and anthropometric features

The burden of low back pain in children and adolescents with overweight and obesity: from pathophysiology to prevention and treatment strategies

Nonspecific low back pain (LBP) is one of the most common causes of disability, affecting all individuals at least once in their lifetime. Such a condition is also becoming increasingly frequent in the pediatric population, especially in children and adolescents with overweight/obesity. Furthermore, new-onset LBP during adolescence has been demonstrated to be a strong predictor of developing LBP later in life, contributing to poorer outcomes and increasing social and medical costs. Several causes and different mechanisms have been considered for the development of LBP in pediatric individuals affected by obesity. For this reason, planning adequate prevention and treatment strategies, mainly through conservative lifestyle changes, would be crucial to anticipate the negative consequences of persisting LBP in adulthood. The aim of this narrative review was to characterize the relationship between LBP and overweight/obesity in the pediatric population, highlighting epidemiological and pathophysiological aspects. In addition, prevention and treatment approaches will be reviewed considering the need to reduce the burden of LBP on this population. According to our search, LBP was more frequent in children and adolescents with overweight and obesity and has been associated with several anthropometric and lifestyle factors, including lumbar hyperlordosis, sedentary habits, physical inactivity, carrying a heavy schoolbag, low vitamin D levels, psychosocial ill-being, and premature intervertebral disc degeneration. Most of these conditions may be addressed with conservative strategies mainly consisting of dietary adjustments, physical exercise, education programs, and physical therapy.

Reliability and Validity of Non-radiographic Methods of Forward Head Posture Measurement: A Systematic Review

Forward head posture measurement can be conducted using various methods and instruments. The selection of the appropriate method requires the factors of validity and reliability to be considered. This systematic review reports on the reliability and validity of the non-radiographic methods examined for measuring forward head posture. The review identified relevant studies following a systematic search of electronic databases. The studies were assessed for quality by two independent reviewers using a critical appraisal tool. The studies’ data were extracted and assessed, and the results were synthesized qualitatively using a level of evidence approach. Twenty-one studies met the eligibility criteria and were included in the review. Both reliability and validity were investigated for five studies, whereas reliability only was investigated for 17 studies. In total, 11 methods of forward head posture measurement were evaluated in the retrieved studies. The validity of the methods ranged from low to very high. The reliability of the methods ranged from moderate to excellent. The strongest levels of evidence for reliability support the use of classic photogrammetry. For validity, the evidence is not conclusive. Further studies are required to strengthen the level of evidence on the reliability and validity of the remaining methods. It is recommended that this point be addressed in future research.

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.

Effect of Deep Cervical Flexor Muscle Training Using Pressure Biofeedback on Pain and Forward Head Posture in School Teachers with Neck Pain: An Observational Study

BACKGROUND

Teaching is one of the professions where incidence and prevalence of neck pain is high. Prolonged use of computers, which has further increased due to online teaching amid pandemic, is known to cause neck pain and alter posture, while people with forward head posture (FHP) are prone to develop neck pain and related disability. Research has shown that impairment of deep cervical flexor (DCF) muscles leads to insufficiency in coordination, activation, overload, and poor support on cervical structures that further lead to development of neck pain and altered neck posture. The objective of this study was to see the effect of DCF muscle training using pressure biofeedback on pain and FHP in school teachers with neck pain.

METHODS

This observational study was conducted at medical center in school premises. Fifty-five school teachers aged between 25 and 40 years with experience of more than 5 years were invited to participate in this study. Subjects were divided in two groups. Both the groups received conventional exercises while in experimental group DCF muscle training using pressure biofeedback was given additionally. Pain and FHP were assessed using NPRS and cranio-vertebral angle using digital photograph technique, respectively, at baseline and end of four weeks of treatment.

RESULTS

Although pain and FHP improved in both the groups, mean improvement in both the measures was more in the group that also received DCF training using pressure biofeedback.

CONCLUSIONS

This study shows that although pain and FHP improved following conventional exercises in school teachers with neck pain, mean improvement was more significant among those who received additional DCF muscle training using pressure biofeedback.

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.

Faulty posture: Prevalence and its relationship with Body Mass Index and Physical Activity among female adolescents

Study aim: The aim of this study was to determine the prevalence of postural disorders and their associated risk factors among high school girls in the city of Tabriz, Iran.

Material and methods: A cross-sectional study was conducted on 400 female students aged 14 to 18 years. Students were examined using a scoliometer, a Debrunner kyphometer, and a flexible ruler, and were directly studied for genu varum/valgum. The information about possible risk factors such as age, BMI, school bag, study time, use of social networks, and physical activity was collected through demographic survey and the International Physical Activity Questionnaire. Data were analyzed by SPSS ver. 22 through independent t-test, chi-square, and logistic regression.

Results: 181 participants (45%) had one or more abnormalities such as scoliosis (4%), kyphosis (5%), genu varum (5.7%), genu valgum (9.7%), hyperlordosis (11.2%), and asymmetrical shoulder (24.5%). The risk of hyperlordosis increased with increase in weight (OR: 1.08, 95%CI: 1.02 to 1.15; p = 0.014) and BMI (OR: 1.37, 95%CI: 1.13 to 1.67; p = 0.002). Moreover, the odds for genu valgum increased with increase in weight (OR: 1.07, 95%CI: 1.01 to 1.13; p = 0.045) and BMI (OR: 1.84, 95%CI: 1.29 to 2.62; p < 0.001); but it decreased with increase in age (OR: 0.62, 95%CI: 0.39 to 0.98; p = 0.039) and not using a study table (OR: 0.31, 95%CI: 0.12 to 0.78; p = 0.013).

Conclusions: Forty-five percent of female students had one or more postural abnormalities. Asymmetrical shoulder was the most common disorder. Weight and BMI were associated with genu valgum and hyperlordosis.

Effect of backpack loading on cervical and sagittal shoulder posture in standing and after dynamic activity in school going children

Background:

Adolescent age group as school going children who experience a period of accelerated growth and development of skeletal and soft tissue. Any daily physical stresses external forces such as load carrying may also influence alignment of the human body. It is assumed that daily intermittent abnormal postural adaptations could result in pain and disability.

Objectives:

To know the effect of backpack loading on cervical and sagittal shoulder posture (SSP) in standing and after dynamic activity in school going children.

Materials and Methods:

The research project was conducted after getting clearance from Human Research Ethics Committee of the H M Patel Institution for Education and research center. Study was conducted on 160 school going children, and measurement were taken to know the loading over the cervical region along with their bagpacks were weighed.

Results:

Total 160 students were enrolled in the present study. Study found that average value of the subject's body weight was 34.83 kg, and subjects backpack weight was 6.42 kg that was equivalent to 18% of the subject's body weight. The mean value of cranio-vertebral angle (CVA) without school bag was 40.62. The mean values of cranio-horizontal angle (CHA) while standing with 18% of body weight and after dynamic activities with 18% of body weight were 24.51 ± 10.3 and 28.93 ± 4.34, respectively. The mean value of SSP without school bag was 39.39 ± 4.31, whereas the mean values of SSP while standing with 18% of body weight and after dynamic activities with 18% of body weight were 54.38 ± 21.19 and 77.62 ± 17.50, respectively.

Conclusions:

Study revealed that there is a significant reduction in the CVA (or increased forward head position), increase in CHA, and SSP were found while carrying a backpack weight 18% of body weight over both shoulders.

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.

Two-dimensional digital photography for child body posture evaluation: standardized technique, reliable parameters and normative data for age 7-10 years

BACKGROUND

Digital photogrammetry provides measurements of body angles or distances which allow for quantitative posture assessment with or without the use of external markers. It is becoming an increasingly popular tool for the assessment of the musculoskeletal system. The aim of this paper is to present a structured method for the analysis of posture and its changes using a standardized digital photography technique.

MATERIAL AND METHODS

The purpose of the study was twofold. The first one comprised 91 children (44 girls and 47 boys) aged 7-10 (8.2 ± 1.0), i.e., students of primary school, and its aim was to develop the photographic method, choose the quantitative parameters, and determine the intraobserver reliability (repeatability) along with the interobserver reliability (reproducibility) measurements in sagittal plane using digital photography, as well as to compare the Rippstein plurimeter and digital photography measurements. The second one involved 7782 children (3804 girls, 3978 boys) aged 7-10 (8.4 ± 0.5), who underwent digital photography postural screening. The methods consisted in measuring and calculating selected parameters, establishing the normal ranges of photographic parameters, presenting percentile charts, as well as noticing common pitfalls and possible sources of errors in digital photography.

RESULTS

A standardized procedure for the photographic evaluation of child body posture was presented. The photographic measurements revealed very good intra- and inter-rater reliability regarding the five sagittal parameters and good reliability performed against Rippstein plurimeter measurements. The parameters displayed insignificant variability over time. Normative data were calculated based on photographic assessment, while the percentile charts were provided to serve as reference values. The technical errors observed during photogrammetry are carefully discussed in this article.

CONCLUSIONS

Technical developments are allowed for the regular use of digital photogrammetry in body posture assessment. Specific child positioning (described above) enables us to avoid incidentally modified posture. Image registration is simple, quick, harmless, and cost-effective. The semi-automatic image analysis, together with the normal values and percentile charts, makes the technique reliable in terms of child's posture documentation and corrective therapy effects' monitoring.

Schoolbags and back pain in children between 8 and 13 years: a national study

Schoolbag weight in schoolchildren is a recurrent and contentious issue within the educational and health sphere. Excessive schoolbag weight can lead to back pain in children, which increases the risk of chronic back pain in adulthood. There is limited research regarding this among the Maltese paediatric population. A cross-sectional study was undertaken across all schools in Malta among students aged 8-13 years (inclusive). Data were collected using a questionnaire detailing schoolbag characteristics, self-reported pain and demographic variables, such as age and gender. Structured interviews with participants were also carried out by physiotherapists. A total of 4005 participants were included in the study, with 20% of the total Malta schoolchildren population. Over 70% of the subjects had a schoolbag that exceeded the recommended 10% bag weight to body ratio. A total of 32% of the sample complained of back pain, with 74% of these defining it as low in intensity on the face pain scale-revised. The presence of back pain was statistically related to gender, body mass index (BMI), school and bag weight to body weight ratio. After adjusting for other factors, self-reported back pain in schoolchildren is independently linked to carrying heavy schoolbags. This link should be addressed to decrease the occurrence of back pain in this age group.

Secular trends in the prevalence of childhood overweight and obesity across Australian states: A meta-analysis

OBJECTIVE

To describe secular trends in the prevalence of overweight and obesity in Australian children in each state and territory.

DESIGN

Systematic search and numerical meta-analysis.

METHODS

A systematic search was conducted to identify all sources that objectively measured the height and weight of Australian children (aged 2-18 years) and had a sample size of at least 300. Raw and summary data were requested from authors and divided into age×sex×state×yearly slices to derive estimates of the prevalence of overweight and obesity. Following a double arcsine transformation to facilitate meta-analysis, all estimates were standardised for age, stratified by sex and analysed using sample-weighted non-linear regressions.

RESULTS

The systematic search identified 73 eligible sources (47 raw and 26 summary datasets), with 72.8% of data sourced from Victoria and South Australia. Prevalence trends varied from state to state, with three states or territories showing a marked plateau, two showing a decline in the more recent years and three showing continued linear increases. Tasmania and Northern Territory generally had the highest prevalence (30.2% and 24.3% overweight and obesity respectively), and the Australian Capital Territory had the lowest (12.4% overweight and obesity).

CONCLUSIONS

Prevalence, as well as prevalence trends, varied amongst Australian states and territories. At a national level, the prevalence trend has nearly plateaued for the past 15 years. However, upward prevalence trends appear to be persisting in Western Australia, South Australia and Tasmania. Findings highlight the need for ongoing efforts to address the issue of childhood obesity.

Comparison of Perceived Backpack Comfort Using Two Rating Scales

Students' current use of backpacks to carry heavy loads of school material has promoted concern about musculoskeletal discomfort and postural problems. The purpose of this study was (a) to compare ratings of perceived comfort between subjects' personal backpacks and an experimental backpack and (b) to compare the data from two comfort rating scales. College-aged students ( N = 19) in a random ordered, cross-over design rated their personal, traditional backpacks and experimental backpacks for perceived neck, shoulder, back, and overall comfort on a 100-mm Visual Analog Scale and on an Anatomical Illustration Rating Scale. Analysis indicated no significant difference in comfort ratings of backpacks on Visual Analog Scale but, on the Anatomical Illustration Rating Scale the experimental backpack was significantly ( p<.05) more comfortable for the back. Further comparisons of backpacks, based on median splits of subjects' weight, height, and body mass index, indicated that body size is related to comfort ratings of backpacks. Special features of the experimental backpack may have contributed to greater comfort in selected areas based on body proportion. Subjective rating systems are not equally sensitive in distinguishing comfort. While backpacks with unique features may improve comfort, manufacturers should consider the size of the users in developing backpack designs.

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

BACKGROUND CONTEXT

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

PURPOSE

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

STUDY DESIGN

This is a cross-sectional study.

PATIENT SAMPLE

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

OUTCOME MEASURES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Electromyography comparison of normal chair-desk system and assistant chair-desk system on fatigue

[Purpose] This study was designed to test the effects of the Assistant Chair-Desk System (ACDS), which can reduce the forward tilt of the neck and trunk and the level of fatigue during long lasting study in the sitting position. [Subjects] Fourteen middle school students and 14 college students of mixed gender participated in this study. [Methods] Fatigue level, the trapezius muscle, and the forward tilt angle of the head and trunk as well as distance factors were assessed before after using a normal chair-desk system (NCDS) and the ACDS for 120 minutes. [Results] There was an interaction effect in the angle and length of the neck from the sitting posture changes after 2 hours of studying using the NCDS and ACDS. There were also significant differences in the fatigue levels, hip joint angles and the lengths from the head according to the main effects of the chair-systems. [Conclusion] The studying position while using the ACDS was determined to prevent significant fatigue levels of the muscle and body, provide support to the head, by limiting the forward movement of the neck, and prevent forward tilt of the neck and trunk, by enabling the target point and gaze to be closer to the horizontal direction.

Reliability of photographic posture analysis of adolescents

[Purpose] Postural problems of adolescents needs to be evaluated accurately because they may lead to greater problems in the musculoskeletal system as they develop. Although photographic posture analysis has been frequently used, more simple and accessible methods are still needed. The purpose of this study was to investigate the inter- and intra-rater reliability of photographic posture analysis using MB-ruler software. [Subjects and Methods] Subjects were 30 adolescents (15 girls and 15 boys, mean age: 16.4±0.4 years, mean height 166.3±6.7 cm, mean weight 63.8±15.1 kg) and photographs of their habitual standing posture photographs were taken in the sagittal plane. For the evaluation of postural angles, reflective markers were placed on anatomical landmarks. For angular measurements, MB-ruler (Markus Bader- MB Software Solutions, triangular screen ruler) was used. Photographic evaluations were performed by two observers with a repetition after a week. Test-retest and inter-rater reliability evaluations were calculated using intra-class correlation coefficients (ICC). [Results] Inter-rater (ICC>0.972) and test-retest (ICC>0.774) reliability were found to be in the range of acceptable to excellent. [Conclusion] Reference angles for postural evaluation were found to be reliable and repeatable. The present method was found to be an easy and non-invasive method and it may be utilized by researchers who are in search of an alternative method for photographic postural assessments.

Traditional posterior load carriage: effects of load mass and size on torso kinematics, kinetics, muscle activity and movement stability

Traditional posterior load carriage (PLC), done without the use of an assistive device (e.g., backpack), has been associated with low back pain (LBP) development. This study evaluated the effects of important task demands, related to load mass and size, on potential mechanisms linking traditional PLC with LBP. Nine healthy participants completed PLC tasks with three load masses (20%, 35% and 50% of individual body mass) and three load sizes (small, medium and large). Torso kinematics, kinetics, muscle activity and slip risk were evaluated during PLC on a walkway, and torso movement stability was quantified during PLC on a treadmill. Increasing load mass caused increased torso flexion, L5/S1 flexion moment, abdominal muscle activity and torso movement stability in the frontal plane. Increasing load size also caused higher torso flexion, peak torso angular velocity and acceleration, and abdominal muscle activity. Complex interactive effects of load mass and size were found on paraspinal muscle activity and slip risk. Specific task demands, related to load mass and size, may thus influence the risk of LBP during PLC.

PRACTITIONER SUMMARY

This study examined the effects of load mass and size on low back pain (LBP) risk using intermediary measures derived from torso kinematics, kinetics and muscle activity. Our current findings, along with earlier work, suggest that load mass and size can influence LBP risk, and that use of smaller and light loads may be beneficial during PLC.

Cervical and shoulder postural assessment of adolescents between 15 and 17 years old and association with upper quadrant pain

Background:

There is sparse literature that provides evidence of cervical and shoulder postural alignment of 15 to 17-year-old adolescents and that analyzes sex differences.

Objectives:

To characterize the postural alignment of the head and shoulder in the sagittal plane of 15 to 17-year-old Portuguese adolescents in natural erect standing and explore the relationships between three postural angles and presence of neck and shoulder pain.

Method:

This cross-sectional study was conducted in two secondary schools in Portugal. 275 adolescent students (153 females and 122 males) aged 15 to 17 were evaluated. Sagittal head, cervical, and shoulder angles were measured with photogrammetry and PAS software. The American Shoulder and Elbow Surgeons Shoulder Assessment (ASES) was used to assess shoulder pain, whereas neck pain was self-reported with a single question.

Results:

Mean values of sagittal head, cervical, and shoulder angles were 17.2±5.7, 47.4±5.2, and 51.4±8.5º, respectively. 68% of the participants revealed protraction of the head, whereas 58% of them had protraction of the shoulder. The boys showed a significantly higher mean cervical angle, and adolescents with neck pain revealed lower mean cervical angle than adolescents without neck pain. 53% of the girls self-reported regular neck pain, contrasting with 19% of the boys.

Conclusions:

This data shows that forward head and protracted shoulder are common postural disorders in adolescents, especially in girls. Neck pain is prevalent in adolescents, especially girls, and it is associated with forward head posture.

Musculoskeletal pain and school bag use: a cross-sectional study among Ugandan pupils

BACKGROUND

Though seen as a convenient method of carrying books and other scholastic materials including food items, schoolbags are believed to contribute to back and other musculoskeletal problems in school going children. This study set out to determine the prevalence of low back and other musculoskeletal pains and describe their relationship with schoolbag use in pupils.

RESULTS

This was a cross-sectional descriptive study involving 532 pupils from six primary schools with a mean age of 13.6 years. Analyses included the chi- square test, independent t tests, regression analysis and test for trend across ordered groups. Backpacks were the most common type of schoolbag and younger children carried disproportionately heavier bags. Urban pupils were younger, carried significantly heavier bags, and less likely to complain about schoolbag weight than the rural pupils. About 30.8% of the pupils carried schoolbags which were more than 10% of their body weight. About 88.2% of pupils reported having body pain especially in the neck, shoulders and upper back. About 35.4% of the children reported that carrying the schoolbag was the cause of their musculoskeletal pain. The prevalence of lower back pain was 37.8%. There was significant association between low back pain and; method of bag carriage (p < 0.0001), long duration of walking (odds ratio 2.67, 95% CI 1.38- 5.16) and the time spent sitting after school (p = 0.02). Only 19% had lockers at school.

CONCLUSION

Urban pupils were younger, carried significantly heavier bags, and less likely to complain about schoolbag weight than the rural pupils. The majority of pupils complained of musculoskeletal pain of which 35.4% was attributed to the schoolbags.The prevalence of lower back pain was 37.8%. Schools need to provide lockers and functional libraries in order to avoid excessive loading and repetitive strain injuries.

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.

The effects of backpack load and carrying method on the balance of adolescent idiopathic scoliosis subjects

BACKGROUND CONTEXT

Concerns have been raised about the effect of backpack carrying on adolescent balance. For adolescent idiopathic scoliosis (AIS) subjects, the effect of backpack carrying method on their balance has not been determined. Our aim is to examine the effects of backpack load and carrying method on AIS subjects' balance.

STUDY DESIGN/SETTING

Paired sample matched for age and sex.

PATIENT SAMPLE

Twelve healthy adolescents matched for age and sex with 14 adolescents with mild AIS participated in this study.

OUTCOME MEASURES

A test battery including clinical examination, radiological assessment, and stabilometric measurements of the postural sways in the upright standing posture were conducted.

METHODS

Center of pressure excursions of our subjects were recorded with a stabilometric platform during the upright standing posture without a backpack and while carrying a backpack symmetrically and asymmetrically on each shoulder. For each carrying method, the backpack is loaded at 10% and 15% of body weight (BW).

RESULTS

Our results indicated that postural sways increased with increasing backpack load. These postural sways were observed when normal adolescents carried a backpack loaded with 15% BW load, whereas, for age- and sex-matched AIS subjects, these postural responses were observed for the 10% BW load. The symmetrical backpack carrying induced better balance compared with the asymmetrical one. Asymmetrical carrying on the convex side of the scoliotic curve affects AIS subjects' balance more than carrying it on the concave side.

CONCLUSIONS

Load carriage of 10% BW seems to alter AIS subjects' balance. Asymmetrical carrying should be avoided especially on the convex side of the scoliotic curve because it causes balance impairments that may increase spinal pain.

Effect of backpack load on the head, cervical spine and shoulder postures in children during gait termination

Twelve boys with an average age of 9.9 years were instructed to carry backpacks that weighed 0%, 10% and 15% of their body weights (BWs) to complete planned and unplanned gait termination experiments. The craniohorizontal, craniovertebral and sagittal shoulder posture angles at the sagittal plane as well as the anterior head alignment and coronal shoulder posture angles at the coronal plane were analysed. Results revealed significantly smaller craniohorizontal and sagittal shoulder posture angles during planned gait termination and a significantly smaller sagittal shoulder posture angle during unplanned gait termination under loaded conditions compared with those at 0% BW backpacks. Furthermore, the coronal shoulder posture angles at 10% and 15% BW during planned and unplanned gait terminations were significantly larger than those at 0% BW. Therefore, subjects were more likely to have a forward head posture, rounded shoulder posture and increased lateral tilting of the shoulders during gait termination as backpack loads were increased. However, gait termination, whether planned or unplanned, did not elicit a remarkable effect on posture.

Schoolbag weight limit: can it be defined?

BACKGROUND

Carrying a schoolbag is a daily activity for most children and much research has been conducted in an effort to identify a safe load limit for children to carry in their schoolbags. Despite this, there is still no consensus about guideline weight and other factors associated with carrying a schoolbag. The objective of this article is to review the literature on schoolbags with particular emphasis on the load limit guidelines and schoolbag-related musculoskeletal pain, and to suggest directions for school health and future research.

METHODS

Science Direct, PubMed, AMED, CINAHL, OVID, EMBASE, and Scopus were searched for peer-reviewed articles using combinations of the following key words: schoolbag, backpack, rucksack, knapsack, satchel, book bag, book pack and included combinations of children, pain, gait, and posture. Article references were also checked for further citations. All are in English, with the exception of one which is in German but is widely cited.

RESULTS

There are conflicting findings in the literature. The recommended load limit for schoolchildren to carry varies from 5% to 20% of their body weight, and the evidence linking backpack weight and back pain is inconclusive.

CONCLUSIONS

The shortcomings in the current literature should be addressed so that evidence-based guidelines can be provided to schoolchildren, parents, and teachers. It is suggested that general guidance may be more appropriate than a single load limit guideline.

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.

Biomechanical evaluation of different abduction splints for the treatment of congenital hip dysplasia

BACKGROUND

Abduction splints for the treatment of hip dysplasia normally operate on curbing the legs at the hip flexion and abduction. The forces are absorbed in different designs of shoulder straps and thus diverted to the shoulder and the spine. The present study is the first comparing these undesired forces of two spread orthoses and subsequently the transmitted forces to the infant's spine.

METHODS

Between March 2009 and October 2009 the hips of 290 infants were investigated by ultrasound within the first 3 days after birth. Thereof 20 infants with a hip dysplasia Graf type IIc, D or IIIa met our inclusion criteria and were investigated with a Tübinger and a Superior abduction splint. Biomechanical evaluation was performed by using a high-sensitive strain gauge sensor applied to the infant's orthoses between pelvic harness and shoulder straps.

FINDINGS

The transmitted forces to the infant's shoulders correlated significantly with their body mass (P<0.05). Maximal forces on the shoulder of the infants and subsequently transmitted forces on the spine were significantly higher (P<0.05) with the Tübinger splint (range 7.6N to 32.3N; arithmetic mean M: 13.7N) in comparison to the Superior orthosis (range 0.0N to 3.5N; M: 0.7N).

INTERPRETATION

The Superior orthosis works with primary load transmission to the pelvic bone. Using the Tübinger splint the shoulders of the newborn infants are loaded with a maximum of 93.9% of their body mass. This may influence the development of the growing infant's spine.

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.

Metabotropic glutamate receptor-5 and protein kinase C-epsilon increase in dorsal root ganglion neurons and spinal glial activation in an adolescent rat model of painful neck injury

There is growing evidence that neck pain is common in adolescence and is a risk factor for the development of chronic neck pain in adulthood. The cervical facet joint and its capsular ligament is a common source of pain in the neck in adults, but its role in adolescent pain remains unknown. The aim of this study was to define the biomechanics, behavioral sensitivity, and indicators of neuronal and glial activation in an adolescent model of mechanical facet joint injury. A bilateral C6-C7 facet joint distraction was imposed in an adolescent rat and biomechanical metrics were measured during injury. Following injury, forepaw mechanical hyperalgesia was measured, and protein kinase C-epsilon (PKCɛ) and metabotropic glutamate receptor-5 (mGluR5) expression in the dorsal root ganglion and markers of spinal glial activation were assessed. Joint distraction induced significant mechanical hyperalgesia during the 7 days post-injury (p < 0.001). Painful injury significantly increased PKCɛ expression in small- and medium-diameter neurons compared to sham (p < 0.05) and naïve tissue (p < 0.001). Similarly, mGluR5 expression was significantly elevated in small-diameter neurons after injury (p < 0.05). Spinal astrocytic activation after injury was also elevated over sham (p < 0.035) and naïve (p < 0.0001) levels; microglial activation was only greater than naïve levels (p < 0.006). Mean strains in the facet capsule during injury were 32.8 ± 12.9%, which were consistent with the strains associated with comparable degrees of hypersensitivity in the adult rat. These results suggest that adolescents may have a lower tissue tolerance to induce pain and associated nociceptive response than do adults.

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.

Asymmetric loads and pain associated with backpack carrying by children

BACKGROUND

Shoulder and back pain in school children is associated with wearing heavy backpacks. Such pain may be attributed to the magnitude of the backpack load and the manner by which children distribute the load over their shoulders and back. The purpose of this study is to quantify the pressures under backpack straps of children while they carried a typical range of loads during varying conditions.

METHODS

Ten healthy children (aged, 12-14 years) wore a backpack loaded at 10%, 20%, and 30% body weight (BW). Backpacks were carried under 2 conditions, low on back or high on back. Pressure sensors (0.1 mm thick) measured pressures beneath the shoulder straps.

RESULTS

When walking with the backpack straps over both shoulders, contact pressures were significantly greater in the low-back condition than in the high-back condition (P = 0.004). In addition, when children carried the backpack in the low-back condition, mean pressures (+/-SE) over the right shoulder were as follows: 98 +/- 31, 153 +/- 48, and 170 +/- 54 mm Hg at 10%, 20%, and 30% BW, respectively, which were significantly higher (P < 0.001) than those over the left shoulder (46 +/- 14, 92 +/- 29, and 90 +/- 29 mm Hg, respectively). Perceived pain with the backpack over 1 shoulder was significantly greater (P = 0.002) than that for donning with both shoulders in the low-back condition.

CONCLUSIONS

Pressures at 10%, 20%, and 30% BW loads on the right or left shoulder, during low-back or high-back conditions, are higher than the pressure thresholds (approximately 30 mm Hg) to occlude skin blood flow. Furthermore, asymmetric and high pressures exerted for extended periods of time may help explain the shoulder and back pain attributed to backpacks.

Postural and subjective responses to realistic schoolbag carriage

The objective of this study was to determine school student's postural and self-reported responses to realistic daily schoolbag carriage and to provide support for an upper schoolbag weight limit. Sixteen boys carried unloaded, 5%, 10%, 12.5% and 15% of body weight (BW) schoolbag loads, each for a simulated school day. The 10% BW condition was repeated with tightened shoulder straps. Participants' posture was quantified and a questionnaire asked them about a number of areas relating to the physical strain caused by each schoolbag. Posture, rating of perceived exertion (RPE) and muscular strain and ability to walk and balance were significantly affected when student's schoolbag load reached 10% BW. It is suggested that 15% BW may be excessive, which supports a schoolbag weight limit of 10% BW for a typical school day. Posture, RPE and muscular strain and ability to walk and balance were not significantly affected by the duration of carriage or by shoulder strap tightness.

Promoting healthy backs in schools: an evaluative study

Purpose

The purpose of this paper is to evaluate the impact of educating adolescents in practical ways of looking after their backs to reduce the incidence of back‐pain, with particular focus on the use and carrying method of ergonomically designed schoolbags.

Design/methodology/approach

An educational leaflet containing a range of back care information was designed specifically for a target population group of Year 7 schoolchildren, aged 11 to 12 years, and distributed to Year 7 students (n=682) attending three main secondary education schools in West Sussex during September 2004. A feedback form was used to evaluate the impact of the leaflet on one class in each school (total n=81).

Findings

The main findings in this paper indicated education had immediate positive impact on students' awareness of the importance of looking after their backs, and achieving positive back‐health. Information gained was likely to influence future choice of schoolbag type, and intention to change to more back‐health aware schoolbook and equipment carrying behaviours.

Research limitations/implications

The paper shows that long‐term impact was not evaluated, and is a limitation of this study. Further research is required to evaluate the long‐term impact of education on back care in adolescents, and at which age optimum educational impact in this area is gained.

Originality/value

This paper contributes evidence, which could be used to inform national and international health agendas, focusing on the specific area of healthy back education for adolescents through a school‐based health promotion initiative.

Effect of prolonged walking with backpack loads on trunk muscle activity and fatigue in children

This study investigated the effect of prolonged walking with load carriage on muscle activity and fatigue in children. Fifteen Chinese male children (age=6 years, height=120.0+/-5.4 cm, mass=22.9+/-2.6 kg) performed 20-min walking trials on treadmill (speed=1.1 ms(-1)) with different backpack loads (0%, 10%, 15% and 20% body weight). Electromyography (EMG) signals from upper trapezius (UT), lower trapezius (LT) and rectus abdominis (RA) were recorded at several time intervals (0, 5, 10, 15 and 20 min), and were normalized to the signals collected during maximum voluntary contraction. Integrated EMG signal (IEMG) was calculated to evaluate the muscle activity. Power spectral frequency analysis was applied to evaluate muscle fatigue by the shift of median power frequency (MPF). Results showed that a 15% body weight (BW) load significantly increased muscle activity at lower trapezius when the walking time reached 15 min. When a 20% BW load was being carried, increase in muscle activity was found from 5 min, and muscle fatigue was found from 15 min. In upper trapezius, increase of muscle activity was not found within the 20-min period, however, muscle fatigue was found from 10 min. No increased muscle activity or muscle fatigue was found in rectus abdominis. It is suggested that backpack loads for children should be restricted to no more than 15% body weight for walks of up to 20 min duration to avoid muscle fatigue.

Postural effects of symmetrical and asymmetrical loads on the spines of schoolchildren

The school backpack constitutes a daily load for schoolchildren: we set out to analyse the postural effects of this load, considering trunk rotation, shoulder asymmetry, thoracic kyphosis, lumbar lordosis, and sagittal and frontal decompensation from the plumbline. A group of 43 subjects (mean age = 12.5 +/- 0.5 years) were considered: average backpack loads and average time spent getting to/from home/school (7 min) had been determined in a previous study conducted on this population. Children were evaluated by means of an optoelectronic device in different conditions corresponding to their usual everyday school backpack activities: without load; bearing 12 (week maximum) and 8 (week average) kg symmetrical loads; bearing an 8 kg asymmetrical load; after fatigue due to backpack carrying (a 7-minute treadmill walking session bearing an 8 kg symmetrical load). Both types of load induce changes in posture: the symmetrical one in the sagittal plane, without statistical significant differences between 8 and 12 kg, and the asymmetrical one in all anatomical planes. Usual fatigue accentuates sagittal effects, but recovery of all parameters (except lumbar lordosis) follows removal of the load. The backpack load effect on schoolchildren posture should be more carefully evaluated in the future, even if we must bear in mind that laws protect workers to carry heavy loads but not children, and results in the literature support the hypothesis that back pain in youngsters is correlated with back pain in adulthood.

Association of relative backpack weight with reported pain, pain sites, medical utilization, and lost school time in children and adolescents

BACKGROUND

There is debate about a 10% versus 15% of body weight cutoff point for safe weight of school backpacks. Estimation of the cutoff may be affected by use of survey methods and failure to assess pain experienced while wearing a backpack. Previous research also suggests that younger students and females are more at risk for developing backpack pain.

METHODS

Five hundred and thirty-one 5th- to 12th-grade Northern California students and their backpacks were weighed. Students were individually interviewed about how often they experienced pain while carrying a backpack, the site of their pain, and if the pain had interfered with school activities or led to medical care.

RESULTS

Data support the use of a 10% of body weight cutoff for safe use of backpacks for all grade levels. Younger students and females are more at risk due to relatively lower body weight while females also carry heavier backpacks than males. Greater relative backpack weight is associated with upper- and mid-back pain reports but not neck or lower back pain; it is also associated with lost school time, lost school sports time, and greater chiropractic utilization.

CONCLUSIONS

The 10% cutoff is recommended along with a variety of practical methods to help schools achieve that goal for middle and high school students.

Back pain and backpacks in school children

OBJECTIVE

Back pain in adults is common and well studied. In contrast, back pain in children has received comparatively little scientific study, despite recent media attention. The purpose of this study is to see what factors influence the prevalence of back pain in middle school children, with particular attention to the weight of children's backpacks and the availability of school lockers.

METHODS

A population-based sample of 1540 children ages 11-14 years in a large metropolitan area was studied. A questionnaire was used to determine presence and severity of back pain, availability of lockers, backpack use, use of 1 or 2 straps to carry backpack, activity limitations due to back pain, and use of pain medication for back pain. Gender, age, weight of the child, and weight of his or her backpack were recorded. Results of scoliosis screening were evaluated with regard to the above information. Data were analyzed using the chi test and univariate or multivariate logistic regression analysis as appropriate.

RESULTS

Overall, 37% of the children reported back pain. Backpacks were used by 97% of children, hence there were too few students not using backpacks to treat backpack use as an independent variable. Multivariate analysis found back pain associated with use of a heavier backpack (P=0.001), younger age (P<0.001), female sex (P<0.001), and a positive screening examination for scoliosis (P=0.009). Children with lockers available reported less back pain (P=0.016). The use of 1 or 2 straps to carry the backpack did not have a significant association with back pain (P=0.588). Of the children who reported back pain, 34% limited their activity due to the pain, 14% use medication for pain relief, and 82% believed their backpack either caused or worsened their pain.

CONCLUSIONS

The incidence of back pain in early adolescence approaches that seen in adults. Recommendations for an "acceptable" weight of backpacks cannot be made from this study, as the weights of students' backpacks seem directly proportional to the likelihood of back pain. This study identifies 2 factors associated with self-reported back pain in early adolescents that are amenable to change: availability of school lockers and lighter backpacks. These findings may be useful in advising families and influencing school policies.

The effect of backpack weight on the standing posture and balance of schoolgirls with adolescent idiopathic scoliosis and normal controls

Concerns have been raised regarding the effect of carrying a backpack on adolescent posture and balance, but the effect of backpack loading combined with other factors affecting balance, such as adolescent idiopathic scoliosis (AIS), has not been determined. This study examines the effects of backpack load on the posture and balance of schoolgirls with AIS and normal controls. The standing posture of 26 schoolgirls with mild AIS (mean age 13, Cobb angle 10-25 degrees ) and 20 age-matched normal schoolgirls were recorded without a backpack and while carrying a standard dual-strap backpack loaded at 7.5%, 10%, 12.5% and 15% of the subject's bodyweight (BW). Kinematics of the pelvis, trunk and head were recorded using a motion analysis system and centre of pressure (COP) data were recorded using a force platform. Reliable COP data could only be derived for 13 of the subjects with AIS. Increasing backpack load causes a significantly increased flexion of the trunk in relation to the pelvis and extension of the head in relation to the trunk, as well as increased antero-posterior range of COP motion. While backpack load appears to affect balance predominantly in the antero-posterior direction, differences between groups were more evident in the medio-lateral direction, with AIS subjects showing poor balance in this direction. Overall, carrying a backpack causes similar sagittal plane changes in posture and balance in both normal and AIS groups. Load size or subject group did not influence balance, but the additive effect of backpack carrying and AIS on postural control alters the risk of fall in this population. Therefore, load limit recommendations based on normal subjects should not be applicable to subjects with AIS.

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.

Changes in Posture and Perceived Exertion in Adolescents Wearing Backpacks with and without Abdominal Supports

OBJECTIVE

The goal was to examine whether backpacks with an abdominal support device improve posture and decrease exertion while walking among adolescents.

DESIGN

Double-blinded trial, with 20 subjects, performed at a University Spine Center. On day 1, adolescents walked on a treadmill for 5 mins with photographic measurement of posture and responded to the Borg scale of perceived exertion before and after ambulation. On day 2, they repeated the trial four more times wearing a backpack randomly loaded with either 10% or 20% of body weight and with or without the Back Balancer abdominal support. Postural measures were recorded by a blinded observer.

RESULTS

Postural changes (forward lean) wearing a backpack with abdominal support were significantly lower while carrying both 10% and 20% of body weight (P = 0.024 and P = 0.008, respectively) vs. no abdominal support. In addition, perceived exertion at 10% and 20% of body weight was significantly greater without abdominal support (P = 0.042 and P = 0.018, respectively).

CONCLUSIONS

Forward lean and perceived exertion while wearing backpacks in adolescents can be significantly decreased with abdominal support. This may increase comfort and decrease complications, such as back pain, that may arise from backpack use.

Reliability of upright posture measurements in primary school children

Background

Correct upright posture is considered to be a measure of good musculoskeletal health. Little is known about the usual variability of children's upright standing posture. The aim of this study was to assess differences between repeated measures of upright posture in a group of primary school children.

Methods

Sagittal plane photographs of usual, relaxed upright standing posture of 38 boys and girls aged 5–12 years were taken twice within an hour. Reflective markers were placed over the canthus, tragus, C7 spinous process, greater trochanter and lateral malleolus. Digitising software was used to calculate the x,y plane coordinates, from which five postural angles were calculated (trunk, neck, gaze, head on neck, lower limb). Height, weight, motor control estimates (as measured by the Brace Tests) and presence of recent pain were recorded for each child, and the association between the first test measure of posture angles and these factors was assessed using linear regression and ANOVA models. Multiple ANOVA models were applied to analyse the effect of repeated testing, and significant predictors on the angles.

Results

Four of the five postural angles (trunk, neck, head on neck, lower limb) were significantly influenced by age. As age was strongly associated with height (r² = 0.84) and moderately associated with weight and motor control (r² = 0.67, 0.56 respectively), these developmental parameters may well explain the age effect on angles. There was no relationship between age and pain reported on either the testing day, or recently, and there was no gender influence on any angle. There was no significant effect of repeated testing on any angle (ICC>0.93). None of the hypothesized predictors were associated with differences in angles from repeated testing.

Conclusion

This study outlined the variability of relaxed upright standing posture of children aged 5–12 years, when measured twice in an hour. Age influenced the size of the angles but not the variability. While the subject numbers in this study are small, the findings provide useful information on which further studies in posture and its development in pre-adolescent children can be based.

Are children's backpack weight limits enough? A critical review of the relevant literature

STUDY DESIGN

Literature review.

OBJECTIVE

To examine the epidemiologic, physiologic, and biomechanical literature that has contributed to the suggested weight limit of 10 to 15% body weight for children's backpacks.

SUMMARY OF BACKGROUND DATA

The majority of children use a backpack to transport their belongings to and from school on a daily basis; however, controversy exists over the safety of backpack use and backpack loads.

METHODS

A thorough review of the literature was completed to examine the appropriateness of the suggested weight limits and to determine future areas of research needed to increase the safety of children's backpacks.

RESULTS

Epidemiologic, physiologic, and biomechanical data support the suggested weight limit of 10% to 15% body weight. CONCLUSIONS.: Based on the current literature, the value of 10% to 15% body weight is a justified weight limit; however, further research is required to determine the association between backpack use and injury and how the factors of load, backpack design, and personal characteristics, such as physical fitness, interact and influence the adaptations required when carrying a backpack.