Exploring the physiological benefits of carrying a suspended backpack versus a traditional backpack.

This study investigates the differences in metabolic energy cost and physiological adaptations between carrying a suspended backpack and a traditional backpack during exercise. For that, 30 males completed the Bruce test while carrying a loaded backpack. Researchers used a metabolic system to obtain variables, analysed muscle oxygen saturation, and used a 2-way RM ANOVA. As results, a significant fatigue interaction was found, but the interaction between fatigue and backpack was non-significant. Using a suspended backpack resulted in energetic advantages in oxygen consumption, muscle oxygen saturation, and performance compared to a traditional backpack. In conclusion, this study offers insights into the physiological implications of using a suspended backpack, suggesting it may reduce the risk of musculoskeletal issues and improve performance for those carrying heavy loads.Practitioner summary: The suspended-load backpacks have been proposed as an alternative to traditional backpacks. This study highlighted that the use of a suspended backpack provided some energetical advantages adaptation compared to the traditional backpack in terms of oxygen consumption, muscle oxygen saturation and performance during a multistage treadmill test walking-running test.

Does a standard school trolley fit children of different heights?

Although school trolleys are an alternative to traditional backpacks, no studies have determined their suitability for children of different heights. This study aims to analyse the fit of a school trolley (0.89 m height from the top to the bottom of the handle) for children with different heights based on kinematic variables and the rate of perceived effort (RPE). A 3D motion capture system was used to analyse the kinematics of the thorax and hip during walking without load and when pulling a trolley loaded with 15% of the child's body weight (BW). The RPE was recorded at the end of each trial. The height of the subjects was clustered using Ward´s hierarchical cluster, and two groups were identified: Group 1: 120-139.9 cm; and Group 2: 140-160 cm. No differences were found between groups in the kinematics or RPE. In conclusion, a standard school trolley fits well to children with heights from 120 to 160 cm. Practitioner Summary: No studies have determined the suitability of school trolleys for children of different heights. This study aims to analyse the fit of a school trolley for children with different heights based on the kinematics and rate of perceived effort. The major finding is that a standard school trolley fits children with heights from 120 to 160 cm well and that the height of the school trolley was between 59% and 68% of the children's heights. Abbreviations: RPE: rate of perceived exertion; BW: body weight; CAST: calibrated anatomical system technique; GC: gait cycle.

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.

Gait asymmetry and rating of perceived exertion: How are they influenced by carrying a backpack and pulling a trolley?

BACKGROUND: Carrying a backpack and pulling a school trolley have been previously related to changes in spatiotemporal gait parameters. OBJECTIVE: Analyze gait asymmetry and rating of perceived exertion carrying a backpack and pulling a trolley with different loads. METHODS: Fifteen students from an elementary school (aged 10.1 ±â€Š1.7 years) participated in this study. The participants walked with no bag, and carrying a backpack or pulling a trolley, both with 10%, 15% and 20% of the participant's body weight (BW). A 3D motion capture system was used to analyze the spatiotemporal gait variables. Then, the ratios, symmetry angles and gait asymmetry of the step length, swing time, and stance time were analyzed. Furthermore, the rating of perceived exertion was recorded. RESULTS: None of the asymmetry parameters were significantly different between those who carried a backpack and those who pulled a trolley. In the backpack condition, the ratings of perceived exertion were higher among participants in the 20% BW (2.07 ±â€Š2.09, p = 0.003) and 10% BW (0.27 ±â€Š0.59, p = 0.004) conditions compared to those in the control condition (0.07 + 0.26). Pulling a trolley did not significantly increase the perceived exertion ratings. CONCLUSIONS: Carrying a backpack and pulling a trolley from 10% - 20% BW did not induce gait asymmetry in children. The use of the school trolley required less subjective effort than carrying a backpack with the same loads.

A kinematic comparison of gait with a backpack versus a trolley for load carriage in children.

The use of a school trolley is reaching and even surpassing the use of backpacks in many countries, although a recommended load has not been studied. To accomplish this, 3D gait kinematics of the lower limbs and thorax were analysed in 49 students walking unloaded, pulling a school trolley or carrying a backpack, all with either 10%, 15%, or 20% BW. The variables obtained were the degrees of flexion/extension, adduction/abduction and internal/external rotation of the thorax, pelvis, hip, knee and ankle. Statistical parametric mapping was used to evaluate differences between conditions and loads throughout the gait cycle. In the backpack conditions, the magnitudes of the differences decreased from proximal to distal joints compared to the unloaded condition. The use of a school trolley only required minor kinematic adaptations. Therefore, from kinematic analysis, it is recommended to avoid loads above 10% BW for children using a backpack and below 20% BW for children using a trolley.

Effect of carrying different military equipment during a fatigue test on shooting performance.

This study investigated the effect of a 3-km walking test (3kWT) carrying different military equipment on shooting performance, rating of perceived exertion (RPE), heart rate (HR), and test time. The relative combat wear and backpack weight (as percentage of soldier's body weight [%BW]) was reported and, along with HR, its relationship to marksmanship variables was tested. Thirty-nine Spanish Army males walked as fast as possible to complete the 3kWT in the following conditions in a randomized order: unloaded walking; wearing the combat uniform; and carrying the combat uniform plus combat backpack. A shooting test was completed before and after the 3kWT. The HR and RPE were evaluated. The marksmanship variables and HR were analysed using a two-way repeated measures ANOVA, and a repeated ANOVA was also used for 3kWT completion time and HR reserve analysis. Correlation analyses were performed between the equipment's weight, HR, and marksmanship variables. The results showed that shooting score decreased after the 3kWT in both load conditions (p < 0.001). The 3kWT time, RPE, and HR increased from control to load conditions, and also between load conditions. The HR reserve showed no significant effects between conditions. The %BW of the backpack condition negatively influenced aiming accuracy (r = -0.35; p = 0.04) and cleanness triggering (r = 0.37; p = 0.03). Correlations between HR and shooting variables were non-significant. In conclusion, wearing the Spanish Army combat wear and backpack resulted in shooting performance degradation. Furthermore, fatigue and RPE increased and this could decrease physical marksmanship and performance capacity in combat situations.

Variability of gait, bilateral coordination, and asymmetry in women with fibromyalgia.

PURPOSE: To analyze how fibromyalgia affected the variability, asymmetry, and bilateral coordination of gait walking at comfortable and fast speeds. METHODS: 65 fibromyalgia (FM) patients and 50 healthy women were analyzed. Gait analysis was performed using an instrumented walkway (GAITRite system). Average walking speed, coefficient of variation (CV) of stride length, swing time, and step width data were obtained and bilateral coordination and gait asymmetry were analyzed. RESULTS: FM patients presented significantly lower speeds than the healthy group. FM patients obtained significantly higher values of CV_StrideLength (p=0.04; p<0.001), CV_SwingTime (p<0.001; p<0.001), CV_StepWidth (p=0.004; p<0.001), phase coordination index (p=0.01; p=0.03), and p_CV (p<0.001; p=0.001) than the control group, walking at comfortable or fast speeds. Gait asymmetry only showed significant differences in the fast condition. CONCLUSION: FM patients walked more slowly and presented a greater variability of gait and worse bilateral coordination than healthy subjects. Gait asymmetry only showed differences in the fast condition. The variability and the bilateral coordination were particularly affected by FM in women. Therefore, variability and bilateral coordination of gait could be analyzed to complement the gait evaluation of FM patients.

The effect of school trolley load on spatiotemporal gait parameters of children.

OBJECTIVE: The present study evaluated spatiotemporal gait parameters in children when they were carrying school trolleys of different weights. METHODS: We assessed four conditions: without trolley, 10%, 15% and 20% of the subject's body weight. Fourteen students from a primary school (aged 11.43±0.51 years) participated in this study. Velocity, cadence, stride length, stance phase, swing phase, single support phase and double support phase were analysed using an electronic walkway. RESULTS: Compared with normal walking, the three load conditions produced significant decreases in swing phase (p<0.001) and single support phase (p<0.001) and significant increases in cadence (p=0.019), stance phase (p<0.001) and double support phase (p<0.001). No statistically-significant differences were found between the three load conditions. CONCLUSION: Compared with normal walking, walking while carrying a trolley produced significant changes in most of the spatiotemporal gait parameters measured, perhaps due to the load-mediated changes in stability and balance. The spatiotemporal gait parameters were similar between the load conditions, indicating that the amount of load did not affect gait.