Background Seated workplaces have greatly increased in China. Many researchers have found that seated work is a risk factor in the development of low-back pain. Backrest can reduce the load on the lower back by transm...Background Seated workplaces have greatly increased in China. Many researchers have found that seated work is a risk factor in the development of low-back pain. Backrest can reduce the load on the lower back by transmitting more of the weight from the upper body to the floor via the backrest so as to prevent low-back pain. To design a suitable chair backrest for seated office work, some backrest parameters must be optimized. In this study, the role of backrest density on lumbar load and comfort were investigated. The goal of the study was to help establish criteria with which backrests that alleviate and prevent low back pain during seated office work can be designed and selected. Methods Twenty volunteers （10 men and 10 women） were seated in three backrest conditions （10 kg/m^3, 25 kg/m^3, and 40 kg/m^3）. Pressure data, including contact pressure （CP）, peak contact pressure （PCP） and contact area were collected during 15-minute trial. Subjective data were collected after each pressure test. Results Backrest density had a significant effect on backrest pressure variables. CP and PCP increased with increasing backrest density. Contact area decreased with increased density. In terms of user preference, the backrest with low density was most highly rated. Conclusions Backrest density plays an important role in lumbar load and comfort during seated work. During designing and selecting backrests, backrest density should be focused on so as to alleviate and prevent low-back pain during seated office work. Backrest density at 10 kg/m^3 got the lowest CP and PCP and largest contact area. Backrest with low density can reduce lumbar pressure and increase support contact area, which could raise comfort feeling. Backrest density at 10 kg/m^3 is better to maintain a balance between providing effective support and alleviating excess lordosis.展开更多
Most of the previous studies on the vibration ride comfort of the human-vehicle system were focused only on one or two aspects of the investigation. A hybrid approach which integrates all kinds of investigation method...Most of the previous studies on the vibration ride comfort of the human-vehicle system were focused only on one or two aspects of the investigation. A hybrid approach which integrates all kinds of investigation methods in real environment and virtual environment is described. The real experimental environment includes the WBV（whole body vibration） test, questionnaires for human subjective sensation and motion capture. The virtual experimental environment includes the theoretical calculation on simplified 5-DOF human body vibration model, the vibration simulation and analysis within ADAMS/VibrationTM module, and the digital human biomechanics and occupational health analysis in Jack software. While the real experimental environment provides realistic and accurate test results, it also serves as core and validation for the virtual experimental environment. The virtual experimental environment takes full advantages of current available vibration simulation and digital human modelling software, and makes it possible to evaluate the sitting posture comfort in a human-vehicle system with various human anthropometric parameters. How this digital evaluation system for car seat comfort design is fitted in the Industry 4.0 framework is also proposed.展开更多
“Ease of comfort” and “functionality” are important factors that have been cited to improve wheelchair seating. The ability to maintain balance and posture while seated in a wheelchair improves stability, comfort,...“Ease of comfort” and “functionality” are important factors that have been cited to improve wheelchair seating. The ability to maintain balance and posture while seated in a wheelchair improves stability, comfort, and functionality and is a prerequisite for daily activities. In this study, the authors used a sitting position measuring device to scientifically verify differences in sitting posture, comfort, and functionality depending on the presence or absence of cushions and the type of cushion in elderly individuals who used wheelchairs. Results suggested that a cushion fabricated by a therapist was more useful than a commercially available air cushion. While a commercially available air cushion was the most suitable, the therapist’s self-made cushion could be expected to demonstrate the same or better applicability than an air cushion.展开更多
文摘Background Seated workplaces have greatly increased in China. Many researchers have found that seated work is a risk factor in the development of low-back pain. Backrest can reduce the load on the lower back by transmitting more of the weight from the upper body to the floor via the backrest so as to prevent low-back pain. To design a suitable chair backrest for seated office work, some backrest parameters must be optimized. In this study, the role of backrest density on lumbar load and comfort were investigated. The goal of the study was to help establish criteria with which backrests that alleviate and prevent low back pain during seated office work can be designed and selected. Methods Twenty volunteers （10 men and 10 women） were seated in three backrest conditions （10 kg/m^3, 25 kg/m^3, and 40 kg/m^3）. Pressure data, including contact pressure （CP）, peak contact pressure （PCP） and contact area were collected during 15-minute trial. Subjective data were collected after each pressure test. Results Backrest density had a significant effect on backrest pressure variables. CP and PCP increased with increasing backrest density. Contact area decreased with increased density. In terms of user preference, the backrest with low density was most highly rated. Conclusions Backrest density plays an important role in lumbar load and comfort during seated work. During designing and selecting backrests, backrest density should be focused on so as to alleviate and prevent low-back pain during seated office work. Backrest density at 10 kg/m^3 got the lowest CP and PCP and largest contact area. Backrest with low density can reduce lumbar pressure and increase support contact area, which could raise comfort feeling. Backrest density at 10 kg/m^3 is better to maintain a balance between providing effective support and alleviating excess lordosis.
基金Supported by National Natural Science Foundation of China(Grant No.51465056)Xinjiang Provincial Natural Science Foundation of China(Grant No.2015211C265)Xinjiang University Ph D Start-up Funds,China
文摘Most of the previous studies on the vibration ride comfort of the human-vehicle system were focused only on one or two aspects of the investigation. A hybrid approach which integrates all kinds of investigation methods in real environment and virtual environment is described. The real experimental environment includes the WBV（whole body vibration） test, questionnaires for human subjective sensation and motion capture. The virtual experimental environment includes the theoretical calculation on simplified 5-DOF human body vibration model, the vibration simulation and analysis within ADAMS/VibrationTM module, and the digital human biomechanics and occupational health analysis in Jack software. While the real experimental environment provides realistic and accurate test results, it also serves as core and validation for the virtual experimental environment. The virtual experimental environment takes full advantages of current available vibration simulation and digital human modelling software, and makes it possible to evaluate the sitting posture comfort in a human-vehicle system with various human anthropometric parameters. How this digital evaluation system for car seat comfort design is fitted in the Industry 4.0 framework is also proposed.
文摘“Ease of comfort” and “functionality” are important factors that have been cited to improve wheelchair seating. The ability to maintain balance and posture while seated in a wheelchair improves stability, comfort, and functionality and is a prerequisite for daily activities. In this study, the authors used a sitting position measuring device to scientifically verify differences in sitting posture, comfort, and functionality depending on the presence or absence of cushions and the type of cushion in elderly individuals who used wheelchairs. Results suggested that a cushion fabricated by a therapist was more useful than a commercially available air cushion. While a commercially available air cushion was the most suitable, the therapist’s self-made cushion could be expected to demonstrate the same or better applicability than an air cushion.
