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

Exploring musculoskeletal discomfort and school bag loads among Thai primary school students: a school-based cross-sectional survey

Musculoskeletal discomfort among children carrying school bags is an increasingly significant problem. This study sought to determine the prevalence and risk factors of musculoskeletal discomfort among Thai primary school students who carry excessively heavy school bags. We conducted cross-sectional descriptive research involving 489 primary school students (ages 7-12). We utilized the standardized Cornell Musculoskeletal Discomfort Questionnaire (CMDQ) to assess discomfort in various body regions. Measurements included student weight, school bag weight, and the angles of neck and trunk inclination. Logistic regression was used to analyze factors influencing musculoskeletal discomfort. The results showed that the majority of students had musculoskeletal discomfort (66.67%). The average relative weight of the school bags was 17.46 ± 6.02%. Significant risk factors for musculoskeletal discomfort included being female (AOR = 1.87, 95% CI = 1.12-3.10), being in grades 1-3 (AOR = 0.221, 95% CI = 0.05-0.91), carrying bags for more than 20 min per day (AOR = 28.87, 95% CI = 8.93-93.31), not storing books at school (AOR = 2.06, 95% CI = 1.07-3.95), and carrying a school bag weighing > 10% of the student's body weight (AOR = 65.46, 95% CI = 14.73-290.93). Additionally, neck and trunk inclinations > 20 degrees were associated with increased discomfort (AOR = 3.25, 95% CI = 1.89-5.57; AOR = 3.26, 95% CI = 1.58-6.70). The prevalence of musculoskeletal discomfort was higher in Thai primary school students. Female, Grades 1-3, carrying bags exceeding 20 min/day, carrying a school bag weighing > 10% of the student's body weight, and neck and trunk inclinations > 20 degrees were predictor variables for musculoskeletal discomfort. Thus, collaborative efforts from educational institutions, educators, parents, and students are essential in addressing this issue.

The impact of backpack load on adolescent's stair descent gait

This study investigates the impact of increasing backpack load on the gait of adolescents during stair descent. Sixteen healthy male students (age = 12.9 ± 0.6 years) were required to descend the stairs in 4 loaded conditions. The kinematic, kinetic, and EMG data were collected synchronously and gait parameters, especially indicators of balance control, were analyzed. The posterior tilt angles (COM-COP IA in the sagittal plane) (0 %-42 %, 48 %-53 %, 58 %-91 %, p < 0.01), trunk anterior tilt angles (9-33 %, 51-65 %, p < 0.01), and CV of stride length (p < 0.01) increased with the backpack load. The COM-Step edge separation decreased with the increased backload (p < 0.01). In addition, the hip flexion torque (25-40 %, 45-51 %, p < 0.01), the rectus femoris activation, and the hip stiffness increased significantly as the load up to 15 % Body Weight (BW)and 20 % BW. The increasing backpack load may affect adolescent's stair descent gait. Especially as the load was up to 15 % BW, the adolescents' bodies tended to tilt backwards relative to the support foot during the single stance phase. They may activate the hip flexors and tilt forward the trunk to recover from the balance perturbation, which was associated with increased hip flexion torques. This adjustment was more pronounced with the increasing backpack load. However, excessive forward flexion may increase the risk of forward falls. The boundaries of adjustment need further research in the future. Findings from this study provide baseline information on the intrinsic mechanisms of balance control during stair descent.

Analytical parameters to check association between load carriage system and bag packs-influenced musculoskeletal complications among school going students: a scoping review

PURPOSE

This study aimed to investigate the correlation between load-carriage systems and backpacks on musculoskeletal complications among school-going students. Additionally, the purpose was to identify research gaps and provide recommendations for future research.

METHODS

To conduct this study, we conducted a thorough search of five databases for literature published between January 2010 and December 2022. Our focus was on original published articles that reported musculoskeletal complications using analytical parameters or outcome measures among school-going students. Two reviewers independently extracted data for eligibility. The studies selected for the analysis focused on musculoskeletal complications and the outcome measures to report these complications.

RESULTS

A total of 3541 titles were screened; of which, 18 observational studies were included. The musculoskeletal complications identified in these studies included lower back, shoulder, and neck pain and disturbed posture. Overall, the quality of the reporting in these studies was deemed satisfactory.

CONCLUSION

Our analysis revealed that pain and postural abnormalities were the most frequently reported complications. Hence, we recommend that future studies incorporate multiple evaluations rather than concentrating on a single symptom.

Influence of School Backpack Load as a Variable Affecting Gait Kinematics among Seven-Year-Old Children

This article investigates schoolchildren's ability to carry an additional load using a backpack (BP). According to scientific research, there is no precise limit to the maximum backpack load, which varies from 10% to 15% of body weight (BW). The purpose of this study was, therefore, to evaluate the influence of an additional external load carried using a backpack on gait kinematics among seven-year-old children in Poland, including assessment of the gender differences. The study was conducted among 26 (13 boys and 13 girls) primary school children aged seven years. The children walked at their preferred speed, under four conditions: with no load (0% BW) and with 10%, 15% and 20% BW. Spatiotemporal parameters were measured using the 2 m Footscan® platform system and photocell Sectro timing system. The children walked more slowly under an additional load. Their step length and single support time decreased. Their base of support, step time and double support time increased. There was no significant effect on their stride length or gait cycle time. The gait kinematic changes were most evident between 10% BW and greater loading. The results highlight how children's gait is affected by carrying additional external loads, which should not exceed 10% BW. That limit is appropriate for both genders.

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

BACKGROUND AND OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Podiatric and Stabilographic Examinations of the Effects of School Bag Carrying in Children Aged 11 to 15 Years

Background: The issues raised in this study were inspired by the concern for the musculoskeletal status of school children. Carrying excess weight in the form of a school bag in this period of life affects the correct body posture of school children. The aim of the study was to analyze the influence of school bags on the feet force distribution on the ground and postural balance in children of both sexes between 11 and 15 years of age. Methods: The study investigated the distribution of pressure forces on the sole of the foot and its arch. The center of pressure for both feet and the whole body was also examined. The participants were 100 students from primary schools in Gdańsk, aged 11 to 15, including 54 girls and 46 boys. The research used a podobarographic platform that measures the distribution of foot pressure to the ground. The examinations included two measurements: in the first, the children stood on the platform in a natural position. Then, a 5 kg backpack was put on and they stood on the platform again. Results: Statistically significant differences were found in the distribution of the foot pressure on the ground in the left metatarsus (p = 0.000) and heel (p = 0.000) after putting on the backpack in both girls and boys. However, in the right foot, these differences concerned the metatarsal area (p = 0.001). The results of the balance tests were only statistically significant in the group of girls in the right foot sway area (p = 0.020). Conclusions: The school backpack load led to an increase in the values of the heel and metatarsal area measured in the students, causing its flattening.