Immediate responses to backpack carriage on postural angles in young adults: A crossover randomized self-controlled study with repeated measures

The impact of varying trolley case usage modes and weights on body posture

OBJECTIVE

To study the body posture characteristics when walking with trolley case, and to explore the effects of different usage methods and weights of trolley case on body posture characteristics.

METHODS

Fifteen subjects pushed and pulled(Condition 1 and 2) the case with three load weights of 10 %, 20 % and 30 % of their own body weight with 0 % no load as baseline for both conditions. The basic gait parameters, kinematic and kinetic data were collected using the VICON infrared motion capture system and a 3D force platform. Two repeated measures factor (condition×weight) analysis of variance was used for statistical analysis of the gait temporal and spatial parameters, as well as trunk angle, kinetic ground reaction force, shoulder joint force, and trunk moment.

RESULTS

Significant condition*weight interactions were detected in DLST (Double Limb Stance Time) (F=5.341，P = 0.006), GRF (Ground Reaction Force) in frontal plane (F=10.507, p < 0.001) and vertical plane (F=3.751, p = 0.021), shoulder joint force in sagittal plane (F=21.129, p < 0.001), and flexion-extension angle of the trunk in the sagittal plane (F=4.888, p < 0.010). Significant main effects were detected in walking speed (F=35.842, p < 0.001), right support time (F=12.156, p < 0.001), left swing time (F=8.506, p < 0.001), left support time (F=1.122, p < 0.001), right step length (F=33.900, p < 0.001), and left step length (F=14.960, p < 0.001) under different weights. A significant main effect was detected in sagittal GRF (F=11.77, p < 0.001), trunk rotation angle (F=4.124, p = 0.016), amplitude of COM (F=2.993, p = 0.046), under different weights.

CONCLUSION

When the weight of the case exceeds 20 % of the body weight, from the perspective of energy efficiency, the push method is more advantageous than the pull method. When walking with luggage, people tend to maintain the stability of their trunk posture by adjusting the force on their arms more often.

Effectiveness of Back care education Programme among school children: a systematic review of randomized controlled trials

STUDY DESIGN

Systematic review of Randomised controlled trials.

OBJECTIVES

With the increasing incidence of back pain among children and its untold implications to their future, back education tailored in an effective way would be indicated. However literature appears unsettled. This study aims to review available literature to determine the effect of school-based back education in preventing and managing low back pain in school children.

METHODS

Randomized controlled trials carried out on elementary and secondary school children of ages 6 to 18 years and published in English language were included. Back education taught in hospitals or other settings were excluded. Primary outcome was back pain prevalence and secondary outcomes were constituted from the study characteristics of selected studies which includes: back behavior, knowledge, postural habits, physical activity, fear-avoidance beliefs, back pack carriage, pain intensity, skills and self efficacy. Databases searched were PEDro, HINARI, PubMed, Cochrane, and Google Scholar. Available stiudies from 2000 to March 2022 were retrieved. Quality of studies were assessed using the PEDro scale. Obtained studies were descriptively analyzed.

RESULTS

A total 8420 studies were retrieved and 8 studies (with 1239 participants) were included in this review. Four studies each assessed back knowledge and back behavior, and two assessed back pain prevalence. There were improvements in back knowledge and back behaviour, but effectiveness of back care education on back pain prevalence was not conclusive. Forms of education used involved the indirect method of conditioning the environment and the direct method which made use of theory, practical lessons and educational books and materials.

CONCLUSION

Back care education programmes in schools are effective in improving back care knowledge, behavior and reduction in low back pain frequency. Reduction in back pain prevalence is not conclusive. Back care education could be incorporated as part of schools' education programmes. Limitations include exclusion of non English language studies and inconsistent outcome measures.

FUNDING SOURCE

None.

REGISTRATION

This review protocol was registered under the International platform of Registered systematic review and meta-analysis protocol (INPLASY) with the registration number; INPLASY202310044 and DOI number; https://doi.org/10.37766/inplasy2023.1.0044.

Impact of Backpacks on Ergonomics: Biomechanical and Physiological Effects: A Narrative Review

(1) Background: the effects of load carriage packs on human gait biomechanics, physiology and metabolism depend on the weight carried, the design of the pack and its interaction with the user. (2) Methods: An extensive search in the PubMed database was performed to find all the relevant articles using the following keywords: backpack, rucksack, backpack ergonomy and sports backpack; 60 articles were included. (3) Results and significance: Double pack (DP) and T-pack (TP) designs are recommended solutions for school children, compared with backpacks (BP). For soldiers and hikers, a backpack remains the best compromise. A hip belt is recommended for BPs as well as for the back of DPs. Shorter and stiffer shoulder straps combined with a higher and tighter load placement on the back provide the best combination in terms of balance, muscle activation and energy expenditure. It is, therefore, possible to determine guidelines for designing the optimal load carriage system, depending on the application. (4) Conclusions: based on the available evidence, DP and TP are advantageous in terms of posture. DP is better than conventional BPs in terms of balance and muscle activation, but has the disadvantage of limited visibility, thermal sensation and obstructed ventilation. In general, it is desirable not to exceed 40% of body mass (BM).

The effect of backpack load position on photographic measures of craniovertebral posture in 150 asymptomatic young adults

BACKGROUND

Altering the horizontal position of the weight in a backpack will influence the magnitude of the external torque it creates but the effect on posture is unclear.

OBJECTIVE

To use photogrammetry to determine if changes in the horizontal position of a fixed backpack weight affect external measures of craniovertebral posture in 150 asymptomatic young adults.

METHODS

A backpack was attached to a steel frame with a bar protruding posteriorly. A fixed load (5% body mass) was placed at three distances along the bar -0 m, 0.20 m, and 0.40 m. Sagittal and frontal plane photogrammetry was used to measure the craniovertebral angle (CVA), upper cervical gaze angle (UCGA) and lateral head tilt angle (LHTA). A comparison was made across unloaded (no backpack) and loaded conditions.

RESULTS

There was a significant decrease in the CVA between unloaded and loaded conditions. Changes in the UCGA were small and, while significant, may not have practical importance. There were no differences in the LHTA between the conditions.

CONCLUSIONS

Changes in the horizontal position of a fixed load affect external measures of craniovertebral posture so consideration needs to be given to not only the weight of a backpack but how the weight is positioned within the backpack.

Musculoskeletal problems and backpack carriage among students in Nigeria

BACKGROUND

The health implication of backpack carriage among school-aged children is a topic of growing research and public health interest. Low weighing backpacks may decrease the risk of musculoskeletal discomforts (MSDs).

OBJECTIVE

To investigate MSDs and their association with backpack carriage practices among secondary school students in eastern Nigeria.

METHOD

Across-sectional study of 404 (243 females and 161 males) secondary school students aged thirteen to seventeen who were residents of Enugu State, Nigeria was conducted. The Modified Standard Nordic Musculoskeletal Questionnaire was adapted and used to collect information onstudents' demographics, musculoskeletal painand backpack carriage. Descriptive statistics (frequencies and percentages) were utilized to summarize results. Chi-square test was used to explore the association between MSD prevalence and backpack carriage practices. Data were analysed using SPSS version 20.0. Alpha level was kept at 0.05.

RESULTS

The average backpack weight carried by the students in this study was 2.49 kg. Shoulder (185, 45.8%), neck (121, 30.0%), upper back (91, 22.6%) and lower back (22, 5.5%) in that order were the body regions most affected by MSDs within the last 12 months. More females than males reported MSDs (60.5% vs 45.2%; x2 = 8.09, p = 0.04). Other students'characteristics and backpack carriage related factors were not associated with MSDs.

CONCLUSION

There is a high prevalence of MSDs among secondary school students in this study but it is not related to backpack carriage. Further research is required to identify the factors responsible for the MSDs, as well as suitable interventions to reduce its impact in this population.