Effects of Backpacks on Ground Reaction Forces in Children of Different Ages When Walking, Running, and Jumping

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.

The Incidence of Body Posture Abnormalities in Relation to the Segmental Body Composition in Early School-Aged Children

Children are exposed to multiple factors that contribute to an increase in body mass and the development of posture defects. The aim of the study is to assess the relationship between the segmental distribution of fat mass and muscle mass and the incidence of body posture abnormalities in early school-aged children. A total of 190 children aged 7-9 were included in the research project. The examined children were divided according to age (class level) into three groups. Height, weight and body composition, BMI, and body posture were determined. Thoracic and lumbar spine abnormalities occurred most frequently in the examined children (7-95%, 8-92%, 9-89.5%). During the assessment of the segmental body composition, the lowest fat-fat-free index was found in the trunk. The number of abnormalities of the cervical spine, pelvis, and lower extremities increases with age. The number of abnormalities of the thoracic and lumbar spine, as well as of upper extremities and the pectoral girdle decreases with age. Body posture abnormalities are correlated with body composition and in particular with the fat mass percentage. The segmental body com-position analyzer can be used to screen for posture defects.

Effect of power training on locomotion capacities in children with cerebral palsy with GMFCS level III-IV

PURPOSE

Power training (PT) is a promising training modality to improve functional abilities in children with cerebral palsy (CP). This study aimed to implement PT in an adapted school and to assess its effect on locomotion capacities in children with Gross Motor Function Classification System (GMFCS) level III-IV.

MATERIALS AND METHODS

Nine children with CP (GMFCS level III-IV) were trained three times/week for 12 weeks. The training sessions took place during the 50-minute physical activity classes and included high intensity exercise. The outcome measures were the performance on the 10-meter comfortable and fast walking tests, the 50-meter sprint test (50M-ST), and the energy expenditure index (EEI).

RESULTS

Participants spent 12 ± 7 and 7 ± 9 min per session at an intensity superior to 40% and 60% of the heart rate reserve, respectively. Performance in the 10-meter walking test (13.5 ± 7.8 to 9.9 ± 4.6 s, p < 0.05), the 10-meter fast walking test (8.8 ± 3.1 to 7.0 ± 3.2 s, p < 0.05), the 6-minute walking exercise (199.0 ± 48.6 to 316.6 ± 107.2 m, p < 0.05), and in 50M-ST (53.8 ± 29.5 to 42.3 ± 16.2 s, p < 0.05) increased after training. The EEI was reduced after training (p = 0.01), resulting in a more efficient gait.

CONCLUSIONS

PT was successfully implemented in children with CP with GMFCS level III-IV. Results suggest that PT increases walking capacities.Implications for rehabilitationPower training (PT) is feasible with children with bilateral cerebral palsy with GMFCS level III and IV.Physical education course in specialist school is a valuable environment to implement PT in children with poor gross motor function.Power training results in locomotion capacities improvement.

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.

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.

Power Backpack for Energy Harvesting and Reduced Load Impact

Long-distance walking with heavy loads is often needed when going hiking or for field rescue, which is prone to cumulative fatigue. There is also a great need for labor-saving and biomechanical energy harvesting in daily life for extended security and communication needs. Here, we report a load-suspended backpack for harvesting the wasted energy of human motion based on a triboelectric nanogenerator (TENG). Two elastomers are incorporated into the backpack to decouple the synchronous movement of the load and the human body, which results in little or no extra accelerative force. With such a design, through theoretical analysis and field experiments, the backpack can realize a reduction of 28.75 % in the vertical oscillation of the load and 21.08 % in the vertical force on the wearer, respectively. Meanwhile, the mechanical-to-electric energy conversion efficiency is modeled and calculated to be 14.02 % under normal walking conditions. The designed backpack has the merits of labor-saving and shock absorption as well as electricity generation, which has the promising potential to be a power source for small-scale wearable and portable electronics, GPS systems, and other self-powered health care sensors.

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

Hintergrund

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

Ziel der Arbeit (Fragestellung)

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

Material und Methoden

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

Ergebnisse

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

Diskussion

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

A Visual Scan Analysis Protocol for Postural Assessment at School in Young Students

The aim of this study was to compare the X-ray diagnosis with a non-invasive method for spine alignment assessment adopting a visual scan analysis with a plumb line and simetograph in middle-school students. The sample of this study was composed of 31 males and 50 females with an average age of 14.23 (± 3.11) years. The visual scan analysis was assessed at a school; whereas, the X-ray was performed in a hospital. The Wilcoxon signed-rank test was used to assess the differences between methods and scoliosis classifications (non-accentuated <10º and scoliosis >10º), and the Kappa was used to assess the agreement between methods. The comparisons between the methods revealed non-significant differences (z = −0.577; p = 0.564), with almost perfect agreement between tests (K = 0.821; p < 0.001). Moreover, no statistical significance was observed between methods by the scoliosis classification (z = −1.000; p = 0.317), with almost perfect agreement between tests (K = 0.888; p < 0.001). This research supports the conclusion that there are no significant differences between the two methods. Therefore, it should be highlighted that this field test should be used by physical education teachers in their classes, or in a school context, in order to determine misalignments or scoliosis prevalence among middle-school students.