[Purpose] This study was performed to investigate the effect of the length of backpack shoulder straps on upper trapezius muscle pain threshold and craniovertebral angle. [Subjects and Methods] There were 25 participants, with ages from 15 to 23 years old. Upper trapezius pain threshold and craniovertebral angle were measured for all subjects without the backpack then re-measured after walking ...

Bodily state plays a critical role in our perception. In the present study, we asked the question whether and how bodily experience of weights influences time perception. Participants judged durations of a picture (a backpack or a trolley bag) presented on the screen, while wearing different weight backpacks or without backpack. The results showed that the subjective duration of the backpack pi...

Perceptual variables such as perceived distance contain information about future actions. Often our goals involve the integration of another’s goals, such as lifting heavy objects together. The purpose of this study was to investigate how another’s actions might influence one’s own goal-oriented perceptions, specifically, verbal distance estimates. Using a within-subject paradigm, we replicated...

OBJECTIVE To explore the backpack load as a percentile of body weight (BW) and its impact on ventilatory function including tidal volume (Vt), vital capacity (VC), forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC, peak expiratory flow (PEF), and maximum voluntary ventilation (MVV) among 9-12 year old Saudi girls. METHODS This is a prospective, experimental ...

researches explore that the backpacks are the most proper tool for carrying daily school equipment, because it can asymmetrically distribute the load. in the present circumstances, more than 80 percent of primary school students in iran use backpack to carry their books and other means. school age children are in a critical musculoskeletal developmental stage, so using non-ergonomic backpack wi...

A growing literature argues that wearing a heavy backpack makes slopes look steeper and distances farther (e.g., Proffitt, 2006). To test for effects of experimental demand characteristics in a backpack experiment, we manipulated the experimental demand of the backpack and then used a postexperiment questionnaire to assess participants' beliefs about the purpose of the backpack. For participant...

[Purpose] This study developed a backpack with a low center of gravity (LCG) and investigated the effects of the LCG backpack on the trunk stability of mountaineers while ascending and descending. [Subjects and Methods] Ten males aged 20-32 years were recruited. The subjects ascended and descended a road with an inclination of 30 degrees wearing the standard or LCG backpack, and trunk accelerat...

background; musculoskeletal disorders (msds) are among the most prevalent pains which could be ignited via material handling. backpack wearers are among those who may carry heavy loads. since msds mainly originate in school-aged children, students (as the largest group of backpack wearers) are considered more important. the purpose of this study is to design a backpack based on minimization of ...

A growing literature argues that wearing a heavy backpack makes slopes look steeper and distances seem longer (e.g., Proffitt, 2006). To test for effects of experimental demand characteristics in a backpack experiment, we manipulated the experimental demand of the backpack and then used a postexperiment questionnaire to assess participants' beliefs about the purpose of the backpack. For partici...