The use of schoolbags and musculoskeletal symptoms among primary school children: are the recommended weight limits adequate?

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.

Evaluation of an ergonomically designed schoolbag: Heart rate variability and body discomfort rating

BACKGROUND: Unsuitable schoolbags may stress the spine and promote poor body posture, particularly for school students. Global recommendations have suggested that schoolbag weight must not exceed 10% of a healthy student’s body mass, which would need continuous monitoring and enforcement. OBJECTIVES: The present study presents a comparison between an ergonomically designed schoolbag, which helps reduce the potential effects of carrying a load, and a commercial one. METHODS: A total of 30 healthy male students were recruited for this experiment. Independent variables determined were schoolbag type (ergonomically designed and commercial schoolbags) and three load levels based on body mass percentage (i.e., 10%, 15%, and 20% of body mass). Heart rate variability (HRV) and body discomfort rating were then measured. RESULTS: Our results showed that the developed schoolbag promoted enhanced subjective measures and HRV response at 15% and 20% of body mass. Participants who wore the developed schoolbags experienced significantly lesser neck, shoulder, upper and lower trunk discomfort than those who wore the traditional ones. Changing the load percentage from 10% to 15% caused an increase in heart rate among participants carrying a commercial schoolbag but a decrease in heart rate among those carrying the developed schoolbag. CONCLUSIONS: The findings presented herein suggest introducing strategies for reducing the potential impact of load carrying through the combined effect of new educational inventions and policy changes.

Non-specific low back pain: cross-sectional study of 11,423 children and youth and the association with the perception of heaviness in carrying of schoolbags

Background

Carrying a schoolbag is a daily activity for most children and adolescents.The perception of a schoolbag’s weight depends upon the individual and is a relevant theme in schoolchildren. Describing the association between the perception of heaviness in carrying a schoolbag and NLBP can facilitate the planning of preventive programs, quite different from those based on specific weight limits for schoolbags in children and youth.

Objective

To determine the prevalence of non-specific low back pain (NLBP) and to analyse the association between the perception of heaviness in carrying of schoolbags and NLBP in Polish children and youth aged 10–19.

Methods

This study included 11,423 children and youth (6,252 girls and 5,171 boys) from Poland. An original questionnaire was used to assess NLBP prevalence.

Results

Among 11,423 of the respondents, 41.5% of the respondents admitted that they had experienced NLBP in the period of the last 12 months. The percentage of individuals reporting NLBP increased with age of participants, p < 0.001. Girls reported NLBP more often than boys (p < 0.001). Students with NLBP declared that their school backpack was heavy more often than students without LBP. Students who thought that their backpacks weighed too much manifested a 1.44 (95% Cl [1.33–1.55]) times higher probability to experience NLBP.

Conclusion

In the examined group of schoolchildren a frequent occurrence of NLBP (41.5%) was noted. Its occurrence was related to female sex and age. Students who thought that their backpacks weighed too much manifested higher probability to develop NLBP.

Does schoolbag carriage equally affect obese/overweight and healthy-weight children?

Discrepancies exist in backpack load recommendations for obese/overweight children, and the recommendations do not consider school trolleys. This study analysed obese/overweight and healthy-weight students' perceived load and fatigue when carrying schoolbags and their gait kinematics and rate of perceived exertion (RPE) when carrying backpacks or pulling school trolleys with different loads. Twelve obese/overweight and 36 healthy-weight students were asked about their perceived load and fatigue in carrying their schoolbags to school. Then, a kinematic gait analysis was completed in students walking unloaded or transporting 10%, 15% or 20% of their bodyweight (BW) in a backpack or trolley. RPE was recorded after each condition. The average hip rotation and knee adduction angles differed between body mass index (BMI) groups. The healthy-weight group reported higher RPEs than the overweight/obese group when pulling a trolley with 10-15% BW. In conclusion, both BMI groups responded similarly to load and schoolbag type.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Development and Experimental Verification of an Ergonomic Backpack

Carrying a heavy school backpack has extensively been reported as a prime cause of children's body strain. It is suggested that the load should not exceed 10 percent of the child's body weight; however, ensuring this requires continuous monitoring. The study explores how ergonomically designed school backpack based on the user anthropometric data (n = 280) and ergonomic parameters help reduce force concentration on shoulders and back. It provides a validation process of the developed prototype by experimental verification. The developed design was assessed in a comparison experiment with a commercially available local school backpack. An experimental study was used which recruited thirty healthy college students (aged 19 to 23 years). Two independent variables evaluated were school backpack type (developed backpack versus commercial one) and load levels as a percentage of body weight. Three load levels were employed 10%, 15%, and 20%. These variables were measured on the responses: bag comfort scale and the percent of maximum voluntary contraction (%MVC) of six muscles (right and left of erector spine, right and left of external abdominal oblique muscle, and right and left of trapezius). The developed backpack provided astonishing performance at levels of 15% and 20% of body weight in terms of subjective measure and electromyography (EMG) responses. It also showed that increasing the carried weight more than 10% result in reducing activity on the erector spinal muscles, while it increases on abdominal oblique muscles. The developed backpack design confirmed the efficiency of its bases by distributing the carried weight among the trunk through side pockets, attached to the body through two upper and lower straps. It helped the body to distribute the carried weight and avoid concentrating pressure on specific areas.

The effect of furniture intervention on the occurrence of musculoskeletal disorders and academic performance of students in North-West Nigeria

BACKGROUND

Mismatch between classroom furniture and the students' anthropometry have been identified as a major cause of musculoskeletal disorders (MSDs) among students. Such discomforts can affect students' performance.

OBJECTIVE

This paper is aimed at investigating the prevalence of MSDs and the effect of furniture intervention among students of tertiary institutions in Northwest Nigeria.

METHODS

The Cornell's MSD questionnaire was used to investigate the prevalence of MSDs in twelve body regions of students aged between 16 and 25 years. Eleven students' anthropometric dimensions were also measured and used to compute the ergonomically compliant furniture dimensions for the participants. A new set of furniture was introduced, and the questionnaire was used to investigate if the intervention made was significant or not. The academic performance of some of the students before and after the intervention was analyzed using the t-test statistical technique.

RESULT

None of the furniture in use was suitable for the majority of the students. MSDs prevalence ranges from 14% to 67.3% among the body regions with the students reporting that low back pain is the most prevalent (67.3%), severe (19.4%) and interfering with their studies (15.8%). The intervention also reduced MSDs in all body regions except at the upper arm and the right side of the forearm. Only sitting, knee, and popliteal heights were significantly associated with MSD occurrence. There was also a significant improvement in the students' academic performance after the intervention (t = -3.239, p = 0.002).

CONCLUSION

The limited success of the intervention is an indication of the need to carry out a more holistic intervention that incorporates other inputs such as continuous enlightenment and classroom facility design.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Classroom Furniture Mismatch and Back Pain Among Adolescent School-Children in Abha City, Southwestern Saudi Arabia

Objective: To explore the potential classroom furniture mismatch with students’ anthropometric measurements and back pain related to sitting for extended periods. Methods: This cross-sectional study was carried out on all twelve male and female intermediate and secondary schools located in Abha city. Anthropometric and classroom furniture measurements were assessed, and the mismatch was determined using standardized methods. Students were also screened for back pain related to long sitting at school. Results: A total number of 879 students was selected. The study revealed seat height mismatch in both intermediate, and secondary school of 84.3%, and 75.6%, respectively. Seat depth mismatch was 74.0% in intermediate schools and reached 84.5% in secondary schools. The desk height was improper for 94.1%, and 82.3% of students in intermediate, and secondary schools, respectively. The levels of mismatch differ significantly by grade level and gender. A prevalence of 10.8% of back pain related to long sitting at school was found. In multivariable logistic regression, males, intermediate school children, and the presence of buttock-popliteal length/seat depth mismatch were significantly associated with pain. On the other hand, practicing exercise was a significant protective factor. Conclusions: There is a prevalent mismatch between students’ dimensions and existing schools’ furniture. School furniture providers should take in consideration the average Saudi students’ dimensions, while designing school furniture especially for males, and at intermediate schools, or provide schools with adjustable seats and desks.

Association of musculoskeletal disorders and workload with work schedule and job satisfaction among emergency nurses

BACKGROUND

The emergency department is a highly demanding work environment, considered by high workload and stress. The impact of work-related factors on musculoskeletal disorders (MSDs) in emergency nurses (ENs) are not yet well understood. We investigated the association of MSDs and workload with work schedule (permanent day and night work) and job satisfaction in ENs.

METHOD

Data were collected through a questionnaire including individual and work-related factors, workload (National Aeronautics and Space Administration-Task Load Index [NASA-TLX]) and MSDs (Standardized Nordic Questionnaire) from 380 ENs in five hospitals.

RESULTS

The findings revealed that work schedule and job satisfaction levels were significantly associated with the MSDs in different body regions. Work schedule was significantly related to physical demand, performance, frustration, and overall workload, whereas it was not to the mental and temporal demands and effort. Job satisfaction level was negatively associated with mental demand and frustration. A high prevalence of musculoskeletal problems, particularly in knees, upper back, lower back, neck and shoulders were found.

CONCLUSION

MSDs are highly prevalent among ENs involved in night work and with low job satisfaction levels. The results are discussed in terms of their implications for emergency hospital nurses. The findings can help to better understand the working conditions and emphasize the need for ergonomic interventions in order to reduce MSDs and workload. Also, the study findings highlight the importance of mental aspects of workload in this occupational group.

Musculoskeletal pain and associated factors among Ethiopian elementary school children

Background

Ethiopian school children often carry school supplies in heavy school bags and encounter limited school facilities. This stresses their vulnerable musculoskeletal system and may result in experiencing musculoskeletal pain. High prevalence of musculoskeletal pain has been documented, but data on musculoskeletal pain among elementary school children in Ethiopia is lacking. To determine the prevalence of musculoskeletal pain and associated factors among elementary school children in Gondar, Ethiopia.

Methods

Cross-sectional study was conducted among children from six randomly selected elementary schools. Sample size was determined proportionally across school grades and governmental and private schools to ensure variety within the sample. Data collection consisted of physical measurements including height, weight and schoolbag weight, and a structured questionnaire on musculoskeletal pain, mode of transport, walking time and school facilities. Data were analysed descriptively and through uni- and multivariate logistic regression model.

Results

In total 723 children participated. The overall prevalence of self-reported musculoskeletal pain was 62%, with a significant difference between school types (governmental 68% versus private 51%). Shoulder, neck and lower leg/knee were most commonly reported. Walking to and from school for ≥20 min (OR = 2.94, 95% CI 2.05 to 4.21) and relative school bag weight (OR = 2.57, 95% CI 1.48 to 4.47) were found significantly associated with self-report musculoskeletal pain. Children with carrying heavy school supplies and also walking long duration have a 3.5 (95% CI = 1.80–6.95) times greater chance of reporting pain as compared to those who carry lesser weighed bags and reported shorter walking duration at the same time.

Conclusions

Prevalence of self-reported musculoskeletal pain was high among children attending public schools and also those who walked a long way to and from school. Long walking duration and relative school bag weight were significantly associated with musculoskeletal pain. These findings can inform policymakers to provide transportation services and other facilities at elementary schools. The findings of this study should be interpreted with caution due to possible social desirability bias with higher prevalence of self-reported pain and more so in children population.

A literature review of anthropometric studies of school students for ergonomics purposes: Are accuracy, precision and reliability being considered?

BACKGROUND

Despite offering many benefits, direct manual anthropometric measurement method can be problematic due to their vulnerability to measurement errors.

OBJECTIVE

The purpose of this literature review was to determine, whether or not the currently published anthropometric studies of school children, related to ergonomics, mentioned or evaluated the variables precision, reliability or accuracy in the direct manual measurement method.

METHODS

Two bibliographic databases, and the bibliographic references of all the selected papers were used for finding relevant published papers in the fields considered in this study.

RESULTS

Forty-six (46) studies met the criteria previously defined for this literature review. However, only ten (10) studies mentioned at least one of the analyzed variables, and none has evaluated all of them. Only reliability was assessed by three papers. Moreover, in what regards the factors that affect precision, reliability and accuracy, the reviewed papers presented large differences. This was particularly clear in the instruments used for the measurements, which were not consistent throughout the studies. Additionally, it was also clear that there was a lack of information regarding the evaluators' training and procedures for anthropometric data collection, which are assumed to be the most important issues that affect precision, reliability and accuracy.

CONCLUSIONS

Based on the review of the literature, it was possible to conclude that the considered anthropometric studies had not focused their attention to the analysis of precision, reliability and accuracy of the manual measurement methods. Hence, and with the aim of avoiding measurement errors and misleading data, anthropometric studies should put more efforts and care on testing measurement error and defining the procedures used to collect anthropometric data.

Risk factors for neck and shoulder pain among schoolchildren and adolescents

AIM

To evaluate the potential risk factors for neck and shoulder pain among schoolchildren.

METHODS

Demographic, physical/leisure activity, school-related and psychosocial factors for neck/shoulder pain were evaluated in a cross-sectional study of 1611 schoolchildren aged 11-14 years.

RESULTS

Neck and shoulder complaints were reported in 27.9 and 19.0% of the sample, respectively. According to multivariate logistic regression models, high desk height (odds ratio (OR) = 2.23, 95% confidence interval (CI): 1.22-4.07), forward-inclined seat pan (OR = 2.38, 95% CI: 1.40-4.05), time spent (30-60 min/day) carrying school bag (OR = 1.61, 95% CI: 1.16-2.23) and psychosocial factors (OR = 1.95, 95% CI: 1.03-3.72) independently increased the risk of neck pain, while low body mass index (OR = 0.63, 95% CI: 0.42-0.95) decreased it. Time spent on watching TV (OR = 1.45, 95% CI: 1.02-2.06), backward-inclined seat backrest (OR = 1.62, 95% CI: 1.02-2.58), curved seat backrest (OR = 1.80, 95% CI: 1.05-3.08), too much homework (OR = 1.45, 95% CI: 1.03-2.03) and psychosocial factors (conduct problems) (OR = 1.63, 95% CI: 1.07-2.46) independently increased the risk of shoulder pain, while prosocial behaviour (OR = 0.56, 95% CI: 0.35-0.90) decreased it.

CONCLUSION

Both physical and psychosocial factors influenced the risk for neck/shoulder pain in school-aged children, suggesting that they should be considered in assessment and treatment of such symptoms in this population.

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

BACKGROUND

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

OBJECTIVE

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

[Factors associated with back pain in adolescents from public schools in one city from South Brazil]

OBJECTIVE

To investigate the prevalence of back pain and associated factors in children attending public schools from South Brazil.

METHODS

A cross-sectional study, conducted between May-July 2014, where a random sample of 619 adolescents, aged 10-17 years of age, was evaluated. The prevalence of back pain was assessed using the Nordic Musculoskeletal Questionnaire, and the independent variables (demographic and biological information, the way of transporting school supplies, and pain during and after the walk) were obtained through a standardized questionnaire. The Poisson regression model was used to estimate unadjusted and adjusted prevalence of back pain in association with the factors investigated.

RESULTS

The prevalence of back pain was 45.2 %, out of which 64.6 % reported pain in one region, 27.1 % in two and 8.3 % in the three regions investigated. After an individual assessment of regions, it was found that the highest prevalence of pain relates to the dorsal region (26.2 %). The most relevant associated factors include female gender (OR=1.43, 95 %CI 1.19-1.74; p<0.01), age between 14 and 17 (OR=1.22; 95 %CI = 1.03-1.45; p=0.02), and dark skin (OR=1.20, 95 %CI 1.01-1.43; p=0.04).

CONCLUSION

The results highlight the need for greater attention to adolescents complaining of back pain, in order to prevent the presence of this chronical disorder in adolescence and later in adulthood. Therefore, it is necessary to educate adolescents and their guardians for the stimulation and consequent adoption of healthy practices for musculoskeletal integrity.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Musculoskeletal symptoms among handicraft workers engaged in hand sewing tasks

Objectives:

This study was conducted to determine the prevalence of musculoskeletal symptoms and associated risk factors among Iranian handicraft workers engaged in different hand sewing tasks.

Methods:

Data were collected using questionnaires (including the Nordic Musculoskeletal Questionnaire) as well as direct observations of posture (using the Rapid Upper Limb Assessment [RULA] method) from 632 workers including carpet handicraft workers (n=222), textiles handicraft workers (n=209), and leather handicraft workers (n=201) in Tabriz, Iran.

Results:

The response rate was 88.8%. The overall prevalence of musculoskeletal complaints, particularly in the neck (57.9%), lower back (51.6%), and shoulders (40.5%) was relatively high. The prevalence of neck and shoulder pain was higher among females and with increasing age. Working posture and fast working were associated with neck, shoulder, and lower back pain. Years worked as a sewing worker was associated with neck and lower back pain. Long duration of continuous sitting work (>2 h) without a break was associated with neck pain. Body mass index, marital status, sport/physical activity, smoking, daily working hours, job satisfaction, and perceived pressure due to work had no effect.

Conclusions:

The findings indicate a high prevalence of musculoskeletal pain among the studied handicraft workers and emphasize the importance of individual, physical, and psychosocial aspects of hand sewing tasks in this regard.

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.

Association of individual and work-related risk factors with musculoskeletal symptoms among Iranian sewing machine operators

This cross-sectional study evaluated working conditions and the occurrence of self-reported musculoskeletal symptoms among 251 Iranian sewing machine operators. A questionnaire and direct observations of working postures using the rapid upper limb assessment (RULA) method were used. A high prevalence of musculoskeletal symptoms, particularly in the neck/shoulders, back and hands/wrists were found. The mean RULA grand score of 5.7 highlighted a poor sewing workstation design and indicated that most operators (with posture assessed at action level 3) needed an investigation and changes in their working habits soon. Work-related factors (including number of years worked as an operator, prolonged working hours per shift, long duration of sitting work without a break, feeling pressure due to work and working postures) and individual factors (including age, gender, BMI and regular sport/physical activities) were associated with musculoskeletal symptoms in multiple logistic regression models. The findings add to the understanding of working conditions of those jobs involving sewing activities and emphasise the need for ergonomic interventions to reduce musculoskeletal symptoms in the future.

Current Backpack Weight Status for Primary Schoolchildren in Colima, Mexico

The purpose of the study was to identify the current status of backpack weight in primary schoolchildren in Colima, Mexico, in relation to gender, school grade level, and body mass index. A cross-sectional study was conducted on 240 randomly selected children from 20 primary schools. The participating children's parents signed statements of informed consent. Descriptive statistics, the χ(2) test, Student's t-test, and Kruskal-Wallis test were used. The mean age was 8.55 ± 2 years (range: 5-12 years). Seventy-eight percent of the schoolchildren presented with a backpack overload that was greater than 10% of their body weight. No significant differences were found in relation to gender. Four out of every five schoolchildren presented with backpack overload, exposing them to a potential health problem. Education and public policy prevention strategies for this situation should be implemented in Mexico and other regions of the world with the same problem.

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.

Neck, shoulder and low back pain in secondary schoolchildren in relation to schoolbag carriage: should the recommended weight limits be gender-specific?

The occurrence of neck, shoulder and low back complaints in relation to schoolbag carriage and other potential risk factors were investigated in a cross-sectional study of 586 Iranian schoolchildren aged 12-14 years. The average load carried by schoolchildren was 2.8 kg. Neck, shoulder and low back complaints during the preceding month were reported by 35.3%, 26.1% and 33% of the students, respectively. Gender was an independent factor predicting musculoskeletal symptoms in schoolchildren. Girls were more likely than boys to suffer from neck, shoulder and low back complaints, although there was no significant difference between genders in terms of schoolbag carriage variables. The findings suggest that the recommended weight limit for schoolbag carriage may need to differ between boys and girls. The associations between schoolbag variables and reported symptoms are also discussed. The results provide evidence that the current weight limit should consider a broader combination of factors that influence the use of schoolbags.

Working conditions of Iranian hand-sewn shoe workers and associations with musculoskeletal symptoms

The working conditions and the prevalence of self-reported musculoskeletal symptoms among 180 Iranian hand-sewn shoe workers were evaluated in this cross-sectional study. Data were collected using both questionnaire (for assessing musculoskeletal symptoms and associated risk factors) and direct observations of posture (by the Rapid Upper Limb Assessment [RULA] method). The prevalence and severity of symptoms was very high among the study population. The mean RULA grand score of 6.2 indicates that in most cases the workers' postures at their workstations need to be investigated and some changes are required immediately. Multiple logistic regression models indicated that the job experience, daily working hours, duration of continuous work without breaks, feeling pressure due to work and working postures were significantly associated with musculoskeletal symptoms of different body regions. The results are discussed in terms of their implications for hand-sewing tasks. These findings can help to better understand the working conditions of those jobs involving hand-sewing operation and highlight the potential for ergonomic interventions to reduce musculoskeletal symptoms among these working groups.

Association of Parental Awareness of Using Schoolbags With Musculoskeletal Symptoms and Carrying Habits of Schoolchildren

The association between parental awareness of using schoolbags and the occurrence of musculoskeletal symptoms and carrying habits of children was investigated in a cross-sectional study in Tabriz, Iran. Data on 454 students aged 11−14 years and their parents ( n = 358) were analyzed. The awareness of the recommended weight limit, appropriate method of carrying schoolbags, and schoolbag strap adjustments was generally low among the respondents. A higher parental awareness of the schoolbag weight was associated with a lower prevalence of upper back and shoulder complaints among children and carrying loads less than 10% of their body weight. The findings suggest that parental awareness should have a more prominent role in changing the schoolbag carrying habits of children and particularly in reducing the weight of loads carried by them. This highlights the need to incorporate guidelines and recommendations into practice to ensure that the health and safety of schoolchildren are not compromised when using schoolbags.