Classroom postures of 8-12 year old children

A systematic review of research on sitting and working furniture ergonomic from 2012 to 2022: Analysis of assessment approaches

This study analyses which aspects of sitting and working furniture ergonomics that may be influenced and how they are assessed. To gather information on the types and assessment techniques connected with influencing furniture ergonomics, a systematic review of the literature was conducted. The papers in the systematic review were published between 2012 and 2022. The articles applied the Systematic Reviews and Meta-Analyses (PRISMA) statement guidelines to limit the 41 papers that were eventually included (N = 41) to those containing keywords like ergonomics, human factors, comfort, working furniture, Chair, assessment and evaluation. The research objective of this systematic review is to provide a comprehensive overview of sitting and working furniture and the main findings, obtaining common assessment techniques for this type of furniture and their suitability. According to the relevant studies, the publications were categorized by summarizing factors like region, gender, research methods, ergonomic assessment techniques and methods used, correlation between assessment techniques and methods, etc. Summaries of the data extracted from the included papers are provided and the applicability of some approaches are assessed. Only a small number of authors have evaluated the ergonomics of furniture used in homes. One of the research gaps is the paucity of research on gender segregation, secular trends, and cultural contexts. These studies heavily rely on quantitative research techniques, and the articles may lack credibility due to the homogeneity of the evaluation techniques. Finally, the authors offer some suggestions for the appropriate ergonomic analysis of furniture.

Post-COVID-19 ergonomic school furniture design under fuzzy logic

BACKGROUND

Because of wrong sitting position, children have back-pain and related musculoskeletal pain (MPD). Due to inappropriate designed class furniture by not taking into account the children's anthropometric measurements have negative effect on children musculoskeletal systems. The impact of the COVID-19 pandemic crisis has changed the furniture industry's production trends.

OBJECTIVE

This study aimed to develop a new fuzzy based design of ergonomic-oriented classroom furniture for primary school students considering the measured anthropometric dimensions of students' safety, health, well-being, i.e. ergonomic criteria, socio-psychological aspect and post-COVID policies.

METHODS

In the study 2049 number of primary school students are assessed considering COVID-19 pandemic policies and their static anthropometric dimensions were measured between 7-10-year-old (between 1st-4th grade students) and descriptive statistics of children among their ages and genders are calculated; mean, standard deviation, percentiles. The data collected from the students were analyzed quantitatively by using Significance Analysis: Mann-Whitney U test statistic, t-test, Regression Analysis and one-way ANOVA. In the study interviews with experts are performed and fuzzy mathematical model (by using fuzzy-AHP, fuzzy-TOPSIS and fuzzy-VIKOR) is developed to calculate Turkey's three schools' furniture.

RESULTS

Results showed statistically significant differences between two genders. And it is observed that the seating bench height is too high for primary school students and lower than the height of the classroom's blackboard from the floor. Fuzzy Multi Criteria Decision Making Method's (FMCDM) results show that primary school students' ergonomic classroom furniture should be mainly designed by considering "COVID-19 Criteria", "Ergonomic Criteria" and "Socio-Psychological Aspect". Students' existing seating benches and tables are changed by considering post-COVID policies/protocols, Ergonomic Criteria and Socio-Psychological Aspect. And a new seating bench/chair and table's dimensions is proposed in the study.

CONCLUSIONS

Children study at school for long periods and their activities involve long periods of time on their desks in schools. As per the results of the study, it can be concluded that school management must consider the genders, ages of students and take into account the post-COVID policies/protocols while procuring the classroom furniture. The COVID-19 pandemic is the single largest event to have affected children globally in their access to school in recent times; estimates suggest that over 85%of the world's total enrolled learners, 1.5 billion children and youths, have been affected. The coronavirus pandemic also creates dramatic changes for the school furniture.

Identification of factors related to behaviors associated with musculoskeletal pain among elementary students

BACKGROUND

Musculoskeletal pains are among evident health problems in children and adolescents. Backpack carrying behaviors and the sitting postures are among behavioral factors associated with musculoskeletal pain in schoolchildren. Therefore, this study aims to identify the factors related to these important musculoskeletal behaviors, using Health Promotion Models.

METHODS

In this cross-sectional study, a questionnaire was created based on PRECEDE Model and Health Belief Model and was administered to 673 Iranian students, whom were selected randomly from elementary schools of Hamadan, Iran, in 2018.

RESULTS

The findings of the study revealed that proper sitting postures and backpack carrying were 42 and 33%, respectively. The findings also showed that predisposing factors including perceived susceptibility (p < 0.05, β = 0.219), perceived severity (p < 0.05, β = 0.166), perceived barriers (p < 0.05, β = - 0.191), perceived self-efficacy (p < 0.05, β = 0.188) and also enabling factors (p < 0.05, β = 0.329) were significantly related to sitting behaviors. Moreover, backpack carrying behaviors had significant relationships with predisposing factors of perceived susceptibility (p < 0.05, β = 0.198), perceived barriers (p < 0.05, β = - 0.258), perceived self-efficacy (p < 0.05, β = 0.185) and reinforcing factors (p < 0.05, β = 0.208).

CONCLUSIONS

It seems necessary for future preventive programs to take factors of musculoskeletal pains among children and adolescents into account.

Text Neck Syndrome in Children and Adolescents

Neck pain is a prevalent health problem, largely reported in adult patients. However, very recent data show that new technologies are inducing a shift in the prevalence of this relevant issue from adulthood to all of the pediatric ages. In fact, the precocious and inappropriate use of personal computers and especially cell phones might be related to the development of a complex cluster of clinical symptoms commonly defined as "text neck syndrome". The purpose of this article is to analyze the new phenomenon of the "text neck syndrome", the underlying causes and risk factors of musculoskeletal pain, that can be modified by changes in routine life, in different cultures and habits, and on the "text neck syndrome" as increased stresses on the cervical spine, that can lead to cervical degeneration along with other developmental, medical, psychological, and social complications. Findings support the contention that an appropriate approach for an early diagnosis and treatment is crucial to properly evaluate this emerging issue worldwide in children and adolescents who spend a lot of time watching smartphones and computers; additional research with more rigorous study designs and objective measures of musculoskeletal pain are needed to confirm significant relationships. Existing evidence is limited by non-objective measures and the subjective nature of musculoskeletal pain.

Relationship between seat surface shape and pressure distribution in school seat models

BACKGROUND

Students remain in a sedentary position inside classrooms for 60% to 80% of their school day. As such, research has associated students' prolonged seated posture on school furniture with their discomfort and musculoskeletal pain. The correlation between the shape of the seat surface and the zones of the body making contact with these surfaces constitutes an essential factor in determining comfort-enhancing seat design.

OBJECTIVE

This study's primary aim lies in contrasting the standard, current school chair against two seat prototypes, both designed and built from digital models, comparing seat-user pressure distribution and contact area during students' performance of different school tasks.

METHODS

Participants (n = 13), ages 7 to 19, performed school tasks sitting on three different chairs' seat surfaces during the test: the current seat used in schools and two seat prototypes, each designed based on body anatomy. The seats were evaluated through a force-sensing array pressure-mapping system.

RESULTS

The measurements from designed seat prototypes provide a better distribution of pressures and greater contact area with the students' anatomical areas (buttocks and thighs) than the seat currently used in the specified schools. The improvement in pressure values and contact area as seen in the second designed seat prototype is due to its inclination angle and contact with students' sacral zone.

CONCLUSIONS

This research work found that a seat's shape based on human anatomical features (buttocks and thighs), compared to a completely flat seat, creates a higher reduction of body pressures and an increase in the body contact area, with the intent to increase comfort and reduce musculoskeletal pain.

Postural habits in adolescents: the influence of a school physiotherapy program on improving the knowledge of postures

Background School physiotherapy programs can promote an increase in health literacy promoting healthier postural habits. This study aimed to verify the effectiveness of this program in improving the theoretical-practical ergonomic knowledge about postures in adolescents and to verify the postural habits adopted. Methods The sample comprised 206 students, 109 (52.9%) being boys, aged 12-19 years old. The measurement instruments included a theoretical-practical test and a scale. The intervention program included one session lasting 90 min, using both theoretical and practical approaches. Results The mean values obtained on the theoretical-practical test before and after the 1-month period were 9.14 ± 2.51 and 13.05 ± 1.41, respectively (p ≤ 0.001). One hundred and ninety-nine (96.6%) students sat with the spine wrongly positioned, 197 (95.6%) students used mobile phones with a cervical flexion, and 165 (80.1%) lifted a heavy object from the floor incorrectly. Conclusions This data revealed that a school physiotherapy program improves ergonomic knowledge in adolescents.

Neck and shoulder pain among elementary school students: prevalence and its risk factors

Background

Neck and shoulder pain is relatively common among children and teenagers and has a negative impact on their physical and psychological health. This study was carried out to assess the prevalence of neck and shoulder pain among elementary school students, and to investigate the relationship between this pain and its risk factors.

Methods

In this cross-sectional study, 693 elementary school students aged 7 to 12 years from Hamadan city, located in western Iran, were selected through the multistage cluster random sampling method. Data were collected through interviews and questionnaires. For the social and psychological variables, the parent version of the Strengths and Difficulties Questionnaire (SDQ) was used. For assessing each student’s posture, an observational checklist, the Rapid Upper Limbs Assessment (RULA), was used. The data was analyzed using the unadjusted (univariate) and adjusted (multivariate) logistic regression.

Results

The prevalence of the neck pain was slightly higher than that of shoulder pain. The prevalence reported over a month was 35.8 and 30.9% for neck and shoulder pain, respectively. The logistic regression analyses showed that, very high desk height (odds ratio (OR) =1.96, 95% confidence interval CI: 1.02–3.74), backward seat pan inclination (OR = 2.10, 95% CI: 1.37–3.24), forward seat pan inclination (OR = 3.12, 95% CI:1.46–6.68), difficulty in viewing the board (OR = 2.54, 95% CI: 1.10–5.84), too much homework (OR = 2.59, 95% CI: 1.49–4.51), RULA score at level III (OR = 2.88, 95% CI:1.64–5.05), and RULA score at level IV (OR = 3.12, 95% CI: 1.72–5.63) increased the risk of neck pain independently. On the other hand, sitting on desk and seat (OR = 0.59, 95% CI: 0.39–0.91) and laying position for doing homework (OR = 0.53, 95% CI: 0.34–0.81) reduced the related risk. Very short desk height (OR = 2.41, 95% CI: 1.26–4.61) and too much homework (OR = 1.94, 95% CI: 1.10–3.42) increased the risk of shoulder pain.

Conclusion

The elementary school students reported a high prevalence of shoulder and neck pain. This study found that improper sitting positions, as well as physical factors such as the school furniture, too much homework, and difficulty in viewing the classroom board, were associated with pain. Proper interventions considering the risk factors assessed in this study, are suggested.

Effects of a muscular stretching and strengthening school-based exercise program on posture, trunk mobility, and musculoskeletal pain among elementary schoolchildren - a randomized controlled trial

Abstract Introduction: The exercise benefits for the most prevalent postural changes require proper investigation, with large samples, control group, and concealed allocation. Objective: To assess the effects of a muscular stretching and strengthening school-based exercise program on posture, trunk mobility, and musculoskeletal pain among elementary schoolchildren. Method: Three hundred students from three schools in Brazil were evaluated. Stretching and strengthening exercises, twice a week, for eight weeks in group sessions were provided by one physiotherapist. The control group did not undergo any intervention. Head, back and shoulder posture were qualitatively evaluated. Head and trunk alignment were evaluated using the Posture Assessment Software. Cervical, thoracic, low back and upper limb pain were assessed for the last seven days. The trunk mobility was recorded through the flexibility of the posterior chain. Posture, pain and trunk mobility were recorded at baseline and after the intervention. Groups were compared using χ2 test, two-way MANOVA, and two-way ANOVA, with α set at 5%. Results: Shoulder posture showed significant results (P = 0.04), the intervention group showed the lower worsening rate. In the quantitative evaluation, a statistically significant difference was observed between assessments (P < 0.01 for head and trunk; ES = 0.53) but not between groups. The intervention group had a higher percentage of improvement in the overall musculoskeletal pain (P = 0.04; ES = 0.54). Mobility decreased an average of 1.8° in the control group and increased 5.0° in the intervention group, without statistical significance. Conclusion: The program was effective in reducing pain level and shoulder misalignment at the intervention group.

Impact of an 8-Month Trial Using Height-Adjustable Desks on Children's Classroom Sitting Patterns and Markers of Cardio-Metabolic and Musculoskeletal Health

During school hours, children can sit for prolonged and unbroken periods of time. This study investigated the impact of an 8-month classroom-based intervention focusing on reducing and breaking-up sitting time on children’s cardio-metabolic risk factors (i.e., body mass index, waist circumference, blood pressure) and perceptions of musculoskeletal discomfort. Two Year-6 classes (24 students per class) in one primary school were assigned to either an intervention or control classroom. The intervention classroom was equipped with height-adjustable desks and the teacher was instructed in the delivery of pedagogical strategies to reduce and break-up sitting in class. The control classroom followed standard practice using traditional furniture. At baseline, and after 8-months, time spent sitting, standing, stepping, and sitting-bouts (occasions of continuous sitting) as well as the frequency of sit-to-stand transitions were obtained from activPAL inclinometers and the time spent in light-intensity physical activity was obtained from ActiGraph accelerometers. Demographics and musculoskeletal characteristics were obtained from a self-report survey. Hierarchical linear mixed models found that during class-time, children’s overall time spent sitting in long bouts (>10 min) were lower and the number of sit-to-stand transitions were higher in the intervention group compared to the control group, while no changes were observed for musculoskeletal pain/discomfort. No significant intervention effects were found for the anthropometrics measures and blood pressure. Height-adjustable desks and pedagogical strategies to reduce/break-up sitting can positively modify classroom sitting patterns in children. Longer interventions, larger and varied sample size may be needed to show health impacts; however, these desks did not increase musculoskeletal pain/discomfort.

Does a prototype 'Experimental' chair facilitate more postural changes in computing adolescents compared to a normal school chair?

BACKGROUND

Prolonged sitting, such as when computing, has been linked to adolescent spinal pain. A chair should fit the user's body dimensions and aid the user in frequently changing sitting posture, rather than support one 'ideal' posture. Such a chair is not currently available to high school learners.

OBJECTIVES

To develop a novel experimental school chair. To determine whether the experimental chair encourages regular small range movement in all directions whilst students work at computers in class. To compare the number of postural changes between the normal static school chair and the experimental chair, whilst students do computing work.

METHODS

A development and validation study was conducted. Twelve high school students were randomly selected from a conveniently selected school. Fifteen minutes of 3D posture measurements were collected in both the prototype and school computer chair. The analysis focused on the frequency of postural movement.

RESULTS

Data of eleven learners were analysed. There were statistically significant increases in the number of postural changes on the 'Experimental' chair compared to the school chair, for both pelvic side-flexion and pelvic rotation (ρ= 0.01).

CONCLUSION

The experimental chair provided more postural movements when compared to the school computer chair. Future studies should use this experimental chair to determine the effect of increased postural movement, of especially the pelvis, on the prevalence and intensity of musculoskeletal symptoms of high school learners in the Cape Metropole area, Western Cape, South Africa.

Anthropometry of Iranian Guidance School Students with Different Ethnicities: A Comparative Study

Objective. We measured some anthropometric dimensions of Iranian guidance school students selected from different ethnicities. Background. Anthropometric dimensions are used for design of equipment, furniture, and clothing. Furniture with inappropriate design not fulfilling the users' anthropometric dimensions may have a negative effect on health. Method. A total of 7400 Iranian guidance school students aged 12-14 years entered the study and their static anthropometric dimensions were measured. Descriptive statistics such as mean, standard deviation, and key percentiles were calculated. All dimensions were compared among different ethnicities and different genders. Results. This study showed significant differences in a set of 22 anthropometric dimensions regarding gender, age, and ethnicity. Conclusion. According to the results of this study, difference between genders and among different ethnicities should be taken into account by designers and manufacturers of guidance school furniture. Application. This study has prepared a data bank of anthropometric dimensions of 12-14-year-old students which can be used as basic information to find appropriate dimensions of school furniture.

Postural dynamism during computer mouse and keyboard use: A pilot study

Prolonged sedentary computer use is a risk factor for musculoskeletal pain. The aim of this study was to explore postural dynamism during two common computer tasks, namely mouse use and keyboard typing. Postural dynamism was described as the total number of postural changes that occurred during the data capture period. Twelve participants were recruited to perform a mouse and a typing task. The data of only eight participants could be analysed. A 3D motion analysis system measured the number of cervical and thoracic postural changes as well as, the range in which the postural changes occurred. The study findings illustrate that there is less postural dynamism of the cervical and thoracic spinal regions during computer mouse use, when compared to keyboard typing.

Effect of Furniture Weight on Carrying, Lifting, and Turning of Chairs and Desks among Elementary School Children

Rearranging furniture in elementary school classrooms encourages classroom activities. In elementary schools in Indonesia and some other developing countries, usually only one style of furniture is used for all children, and the furniture is heavy and oversized for younger children. This affects their ability to carry it. The objective of this study is to investigate the effects of elementary school furniture weight and children’s age on performance of three carrying tasks (carrying a chair, lifting and turning a chair on a desk, and carrying both a chair and a desk together), from the ergonomics point of view. A total of 42 schoolchildren (ages 6–9; 17 Indonesian, 25 Japanese) participated in this study. Two types of Japanese chairs (Chair A and B, weight: 3.2 kg and 3.9 kg), one type of Indonesian chair (Chair C, weight: 5.0 kg), and two types of desks (height: 58 cm and 68 cm) were used. Indonesian chairs took significantly longer time to carry than the two Japanese chairs, and there was a significant negative relationship between age and task time for Chairs B and C, but not Chair A. Success rates for lifting and turning the chair declined as age decreased and chair weight increased, but were not significantly influenced by desk height. Success rates for carrying a chair and desk together significantly decreased with heavier furniture. Children aged six showed an extremely low success rate in almost all conditions. In conclusion, children’s ability to carry furniture is affected by their age and furniture characteristics, especially weight. In order to encourage classroom activities in elementary school, school furniture should be of appropriate weight. Supervision for younger children is required during classroom furniture arrangement.

The spinal posture of computing adolescents in a real-life setting

Background

It is assumed that good postural alignment is associated with the less likelihood of musculoskeletal pain symptoms. Encouraging good sitting postures have not reported consequent musculoskeletal pain reduction in school-based populations, possibly due to a lack of clear understanding of good posture. Therefore this paper describes the variability of postural angles in a cohort of asymptomatic high-school students whilst working on desk-top computers in a school computer classroom and to report on the relationship between the postural angles and age, gender, height, weight and computer use.

Methods

The baseline data from a 12 month longitudinal study is reported. The study was conducted in South African school computer classrooms. 194 Grade 10 high-school students, from randomly selected high-schools, aged 15–17 years, enrolled in Computer Application Technology for the first time, asymptomatic during the preceding month, and from whom written informed consent were obtained, participated in the study. The 3D Posture Analysis Tool captured five postural angles (head flexion, neck flexion, cranio-cervical angle, trunk flexion and head lateral bend) while the students were working on desk-top computers. Height, weight and computer use were also measured. Individual and combinations of postural angles were analysed.

Results

944 Students were screened for eligibility of which the data of 194 students are reported. Trunk flexion was the most variable angle. Increased neck flexion and the combination of increased head flexion, neck flexion and trunk flexion were significantly associated with increased weight and BMI (p = 0.0001).

Conclusions

High-school students sit with greater ranges of trunk flexion (leaning forward or reclining) when using the classroom computer. Increased weight is significantly associated with increased sagittal plane postural angles.

Is there a difference in head posture and cervical spine movement in children with and without pediatric headache?

Pediatric headache is an increasingly reported phenomenon. Cervicogenic headache (CGH) is a subgroup of headache, but there is limited information about cervical spine physical examination signs in children with CGH. Therefore, a cross-sectional study was designed to investigate cervical spine physical examination signs including active range of motion (ROM), posture determined by the craniovertebral angle (CVA), and upper cervical ROM determined by the flexion-rotation test (FRT) in children aged between 6 and 12 years. An additional purpose was to determine the degree of pain provoked by the FRT. Thirty children (mean age 120.70 months [SD 15.14]) with features of CGH and 34 (mean age 125.38 months [13.14]) age-matched asymptomatic controls participated in the study. When compared to asymptomatic controls, symptomatic children had a significantly smaller CVA (p < 0.001), significantly less active ROM in all cardinal planes (p < 0.001), and significantly less ROM during the FRT (p < 0.001), especially towards the dominant headache side (p < 0.001). In addition, symptomatic subjects reported more pain during the FRT (p < 0.001) and there was a significant negative correlation (r = -0.758, p < 0.001) between the range recorded during the FRT towards the dominant headache side and FRT pain intensity score. This study found evidence of impaired function of the upper cervical spine in children with CGH and provides evidence of the clinical utility of the FRT when examining children with CGH.

Classification-guided versus generalized postural intervention in subgroups of nonspecific chronic low back pain: a pragmatic randomized controlled study

STUDY DESIGN

Pragmatic randomized controlled single-blinded study.

OBJECTIVE

To compare the effects of the classification system guided postural intervention (CSPI) with generalized postural intervention (GPI) in subgroups of nonspecific chronic low back pain (NSCLBP).

SUMMARY OF BACKGROUND DATA

Spinal motor control impairments and the associated alterations in spinal postures adopted by patients with NSCLBP are highly variable. Research evaluating the effect of interventions that target the specific movement/posture impairments in NSCLBP subgroups is therefore warranted.

METHODS

A total of 49 patients with NSCLBP with a classification of flexion pattern (n = 29) and active extension pattern (n = 20) control impairment were recruited from a large cohort study and randomly assigned into CSPI and GPI. The primary outcome was change in Roland-Morris Disability Questionnaire, secondary outcomes were change in pain visual analogue scale, spinal repositioning sense including thoracic and lumbar absolute error, variable error, constant error, and trunk muscle activity during sitting and standing. The intervention was evaluated at baseline, immediately post one-to-one intervention and post 4-week home-based training.

RESULTS

The CSPI produced statistically and clinically significant reduction in disability (4.2 [95% CI, 2.9-5.3]) and pain (2, [95% CI, 1.3-2.6]) compared with minimal change in the GPI disability (0.4, [95% CI, -0.8 to 1.6]) and pain (-0.2, [95% CI, -0.5 to 0.9]). Repeated measures analysis of variance revealed that CSPI significantly reduced absolute error in thoracic (sitting) and lumbar spine (standing) and constant error in lumbar spine (standing) post one-to-one phase, although this was no longer significant at 4 weeks. Neither intervention had an effect on trunk muscle activity.

CONCLUSION

Compared with minimal change in the GPI group, the CSPI produced statistically and clinically significant improvements in disability and pain outcomes and short-term improvements in some parameters of spinal repositioning sense in NSCLBP subgroups.

A systematic review of the relationship between sitting and upper quadrant musculoskeletal pain in children and adolescents

BACKGROUND

Upper quadrant musculoskeletal pain (UQMP) is a common health problem in children and adolescents. The upper quadrant refers to the occiput, cervical and upper thoracic spine including the clavicles and scapulae. The current literature, which indicates that sitting, in terms of sedentary activities and sitting spinal posture, is a possible risk factor of UQMP, is controversial. This systematic review is aimed at ascertaining whether there is evidence for sitting as a risk factor for UQMP, and determining the different elements of sitting that are related to UQMP experienced by children and adolescents.

METHODS

Six electronic databases, BioMed Central (2007-2011), CINAHL (2007-2011), Proquest (2007-2011), Pubmed (2007-2011), Science Direct (2007-2011) and SCOPUS (1960-2011) were searched. The eligible papers were appraised using a standardised critical appraisal tool, the Critical Appraisal Tool for Quantitative Studies (Law et al., 1998).

RESULTS

Ten papers were eligible for the review. Four papers reported significant positive associations between sitting and UQMP in children and adolescents. Five elements of sitting were identified as relating to UQMP. Those were sitting duration; activities while sitting; activities while sitting and sitting duration; dynamism; and postural angles.

CONCLUSION

There is unequivocal evidence that sitting and UQMP are related in children and adolescents. End of range postural angles should be considered as possible risk factors and these elements of sitting should be explored in future research.

Classroom furniture and anthropometric characteristics of Iranian high school students: proposed dimensions based on anthropometric data

The study evaluated the potential mismatch between classroom furniture dimensions and anthropometric characteristics of 978 Iranian high school students (498 girls, 480 boys), aged 15-18 years. Nine anthropometric measurements (stature, sitting height, sitting shoulder height, popliteal height, hip breadth, elbow-seat height, buttock-popliteal length, buttock-knee length and thigh clearance) and five dimensions from the existing classroom furniture were measured and then compared together (using match criterion equations) to identify any potential mismatch between them. The results indicated a considerable mismatch between body dimensions of the students and the existing classroom furniture, with seat height (60.9%), seat width (54.7%) and desktop height (51.7%) being the furniture dimensions with a higher level of mismatch. The levels of mismatch varied between the high-school grade levels and between genders, indicating their special requirements and possible problems. The proposed dimensions of the classroom furniture more appropriate for the students were given. This additional information on students' anthropometry can be used by local furniture industries as a starting point for designing more appropriate furniture for school children, or used by schools to aid in furniture selection.

An epidemiologic study on anthropometric dimensions of 7-11-year-old Iranian children: considering ethnic differences

Anthropometric data can be used to identify the physical dimensions of equipment, furniture, clothing and workstations. The use of poorly designed furniture that fails to fulfil the users' anthropometric dimensions, has a negative impact on human health. In this study, we measured some anthropometric dimensions of Iranian children from different ethnicities. A total of 12,731 Iranian primary school children aged 7-11 years were included in the study and their static anthropometric dimensions were measured. Descriptive statistics such as mean, standard deviation and key percentiles were calculated. All dimensions were compared among different ethnicities and different genders. This study showed significant differences in a set of 22 anthropometric dimensions with regard to gender, age and ethnicity. Turk boys and Arab girls were larger than their contemporaries in different ages. According to the results of this study, difference between genders and among different ethnicities should be taken into account by designers and manufacturers of school furniture.

PRACTITIONER SUMMARY

In this study, we measured 22 static anthropometric dimensions of 12,731 Iranian primary school children aged 7-11 years from different ethnicities. Descriptive statistics such as mean, standard deviation and key percentiles were measured for each dimension. This study showed significant differences in a set of 22 anthropometric dimensions in different genders, ages and ethnicities.

High frequency of McKenzie's postural syndrome in young population of non-care seeking individuals

OBJECTIVES

The role of postural loads as a risk factor for back pain and musculoskeletal symptoms is unclear. McKenzie proposed in his classification of mechanical syndromes a postural syndrome, in which people only develop symptoms from sustained loading, which is relieved by a change in position and has no effect on movement or function. Because of the low level disability with postural syndrome, it was suggested that few seek healthcare for this problem.

METHODS

This study used a two-stage process first to give a questionnaire to 100 students and staff from a university to determine who appeared to have postural syndrome, and then applied a physical examination to those who consented.

RESULTS

One hundred and thirty-eight were approached, of who 100 completed questionnaires and 66% appeared to have postural syndrome. Of the 66 who appeared to have postural syndrome, 37 consented to have a physical examination. Of the 37, 31 met the criteria for postural syndrome, with postural syndrome being significantly associated with pain on sustained loading and pain abolition on posture correction. Most postural syndrome was in the lumbar spine and associated with sitting, but other sites and causes were also noted.

DISCUSSION

This study lends credibility to McKenzie's postural syndrome, but also suggests this as a possible precursor for future more disabling or painful problems. Postural syndrome may not feature in those seeking professional healthcare, but is clearly highly prevalent in a young population.

Spinal position sense and trunk muscle activity during sitting and standing in nonspecific chronic low back pain: classification analysis

STUDY DESIGN

A cross-sectional study between subgroups of nonspecific chronic low back pain (NSCLBP) and asymptomatic controls.

OBJECTIVE

To investigate NSCLBP subgroup differences in spinal position sense and trunk muscle activity when repositioning thoracic and lumbar spine into neutral (midrange) spinal position during sitting and standing.

SUMMARY OF BACKGROUND DATA

Patients with NSCLBP report aggravation of symptoms during sitting and standing. Impaired motor control in NSCLBP, associated with sitting and standing postures nearer the end range of spinal motion, may be a contributing factor. Rehabilitation improving neutral (midrange) spinal position control is advocated. Postural and motor control alterations vary in different NSCLBP subgroups, potentially requiring specific postural interventions. There is limited evidence on whether subgroup differences exist when performing neutral spine position tasks.

METHODS

Ninety patients with NSCLBP and 35 asymptomatic controls were recruited. Two blinded practitioners classified NSCLBP into subgroups of active extension pattern and flexion pattern. Participants were assisted into neutral spine position and asked to reproduce this position 4 times. Absolute, variable, and constant errors were calculated. Three-dimensional thoracic and lumbar kinematics quantified the repositioning accuracy and surface electromyography assessed back and abdominal muscles activity bilaterally.

RESULTS

Irrespective of subclassification, patients with NSCLBP produced significantly greater error magnitude and variability than the asymptomatic controls, but subgroup differences were detected in the error direction. Subgroup differences in the trunk muscle activity were not consistently identified. Although both subgroups produced significantly higher abdominal activity, subclassification revealed difference in superficial multifidus activity during standing, with flexion pattern producing significantly greater activity than the asymptomatic controls.

CONCLUSION

Subgroups of NSCLBP had similar neutral spinal position deficits regarding error magnitude and variability, but subclassification revealed clear subgroup differences in the direction of the deficit. The trunk muscle activation was shown to be largely nondiscriminatory between subgroups, with the exception of superficial lumbar multifidus.

Sitting postures and trunk muscle activity in adolescents with and without nonspecific chronic low back pain: an analysis based on subclassification

STUDY DESIGN

A preliminary cross-sectional comparative study of adolescents with nonspecific chronic low back pain (NSCLBP) and healthy controls.

OBJECTIVE

To investigate whether differences in spinal kinematic and trunk muscle activity exist in both usual and slump sitting in adolescents with NSCLBP.

SUMMARY OF BACKGROUND

Evidence suggests that low back pain commonly develops in adolescence and increases the risk for low back pain in adulthood. Sitting is an important consideration in adolescents with NSCLBP: currently there are no reports investigating their motor control strategies in sitting.

METHODS

Twenty-eight adolescents (14 female) with NSCLBP and 28 matched pain-free controls were recruited from a large cohort study. Pain subjects were subclassified based on O'Sullivan's classification system. Three-dimensional lumbo-pelvic kinematic data and the activation of 3 back and 2 abdominal muscles were recorded during usual and slump sitting. The flexion-relaxation phenomenon in sitting was also investigated.

RESULTS

Spinal posture in usual and slump sitting were similar for adolescents with and without NSCLBP. However, differences were identified in both sitting conditions when those with NSCLPB were subclassified and compared with controls. Muscle activation differences were not consistently identified, with only lower levels of internal oblique activation in usual sitting in NSCLBP compared with pain-free controls showing significance. Flexion relaxation was observed in both iliocostalis and thoracic erector spinae in the NSCLBP group but not controls.

CONCLUSION

This study provides preliminary results. Differences with sitting posture are only seen when adolescents with NSCLBP are classified. Trunk muscle activation is not a sensitive marker for discriminating subgroups of NSCLBP during adolescence.

Evidence-based guidelines for the wise use of computers by children: physical development guidelines

Computer use by children is common and there is concern over the potential impact of this exposure on child physical development. Recently principles for child-specific evidence-based guidelines for wise use of computers have been published and these included one concerning the facilitation of appropriate physical development. This paper reviews the evidence and presents detailed guidelines for this principle. The guidelines include encouraging a mix of sedentary and whole body movement tasks, encouraging reasonable postures during computing tasks through workstation, chair, desk, display and input device selection and adjustment and special issues regarding notebook computer use and carriage, computing skills and responding to discomfort. The evidence limitations highlight opportunities for future research. The guidelines themselves can inform parents and teachers, equipment designers and suppliers and form the basis of content for teaching children the wise use of computers. STATEMENT OF RELEVANCE: Many children use computers and computer-use habits formed in childhood may track into adulthood. Therefore child-computer interaction needs to be carefully managed. These guidelines inform those responsible for children to assist in the wise use of computers.

A comparison of posture and muscle activity during tablet computer, desktop computer and paper use by young children

Computers are now widely used by children. Tablet computers are becoming widely available and promoted for use by school children. The primary objective of this study was to compare the posture and muscle activity of children using a tablet computer to the posture and muscle activity of children using a desktop computer and paper technology. Eighteen children (mean age 5.6 years) performed a colouring-in task in tablet, desktop and paper conditions. 3-D posture and muscle activity around the neck and shoulder was assessed. Tablet computer use was similar to paper use, with less neutral spinal posture, more elevated scapular posture and greater upper trapezius and cervical erector spinae activity. This was offset by greater variability of posture and muscle activity. Tablet computer use clearly results in different musculoskeletal stresses than desktop computer use. Computer use guidelines need to be appropriate to traditional and emerging technologies. Tablet computers are being promoted for use by adults and children. However, the physical impact of using this type of technology is not known. The findings of this study provide the first tablet-specific evidence to inform guidelines on wise use of tablet computers by children.