Office Chair Research Articles

Effects of a 30-min rest with a nap chair on task performance, sleepiness, and neurophysiological measures in men with suspected brain fatigue: a randomized controlled crossover trial

BackgroundIt has been suggested that a short nap in the afternoon may improve sleepiness, alertness, and task performance. The present study evaluated the effects of a 30-min rest with a new nap chair on task performance, sleepiness, and neurophysiological measures.MethodsA randomized controlled crossover trial with a 1-week interval was carried out at the BOOCS Clinic Fukuoka in Japan. The subjects were male workers aged 20 to 64 years with suspected brain fatigue, which was defined by the Profile of Mood Status 2. The intervention was a 30-min rest with an office chair or a nap chair. The primary outcome was the performance in the Uchida-Kraepelin test. The secondary outcomes included the Karolinska Sleepiness Scale and 15-min heart rate variability (HRV). The changes after the nap-chair rest and office-chair rest were compared. Repeated measures analysis of variance with nesting was used in the statistical analysis.ResultsTwenty participants were eligible and entered the crossover trial. The overall 15-min score in the Uchida-Kraepelin test improved after the nap-chair rest and after the office-chair rest to almost the same extent (5.9 vs. 5.5 points, P = 0.68). The Karolinska Sleepiness score significantly decreased after the nap-chair rest, and the between-treatment difference in the decrease was highly significant (P = 0.0004). The average duration of sleep during rest was prominently longer in the nap-chair rest than in the office-chair rest (19.0 vs. 7.6 min, P = 0.002). No participants experienced REM sleep during the rest. LF and HF powers of the HRV were greater during the nap-chair rest than during the office-chair rest, the difference in the HF power being substantial.ConclusionA 30-min rest with the nap chair did not appreciably improve the performance in the Uchida-Kraepelin test as compared with the office-chair rest. The nap-chair rest induced a substantially longer sleep accompanied with a parasympathetic activation, thereby resulting in a material improvement in sleepiness after the rest.

Workers with Disabilities and the Challenges of Creating an Inclusive Work Environment

Introduction. Creating a workplace for workers with disabilities is a difficult task that requires considering a variety of factors. Many workplaces are not equipped with the necessary devices, such as height-adjustable tables, office chairs for disabled, or wheelchair lifts. Also, buildings may lack wheelchair ramps, elevators or wide doorways, which makes it difficult for people with limited mobility to access the workplace. These and many other factors significantly limit the possibilities of professional integration of persons with disabilities.The purpose of this work was to identify the main challenges of creating an inclusive working environment in order to increase the employment rates of workers with disabilities. In this research, an analysis of Russian and foreign literature was carried out.Materials and methods. The issues of the employment of workers with disabilities and the creation of an inclusive working environment were considered on the basis of a content analysis of scientific, review, and expert literature published both in scientific peer-reviewed publications and on the Internet. Papers by Rus-sian and foreign authors, analytical data from national statistical agencies, and materials from government and corporate programs aimed at integrating persons with disabilities into social and professional life were studied.Results. Discussions on disability in the workplace have been extremely limited for a long time. However, statistics show that 5–8% of the working-age population have health problems that limit their ability to carry out professional activities. The workplace should be accessible to all employees, whether for routine work or emergency evacuation. Effective use of international experience as well as continuous improvement of inclu-sive practices will help to create more accessible and fair working conditions for all.

Thermal insulation provided by chairs with various clothing ensembles

The thermal insulation provided by chairs significantly influences human thermal comfort. On the one hand, it modifies the heat exchange mechanism at the contact points between the body and the chair surface. On the other hand, an increase in local thermal insulation can exacerbate differences in thermal insulation across various areas of the body, impacting overall comfort. However, the thermal insulation data for chairs are decades old and thus need to be updated to reflect modern designs and materials. Six typical office chairs were tested using a thermal manikin dressed in five typical clothing ensembles (ranging from summer to winter). The effective thermal insulation of the chairs varied between 0.04 and 0.14 clo when tested in the nude. The added values ranged from 0.04 to 0.30 clo when tested with different clothing ensembles. Higher clothing levels correspond to higher added chair thermal insulation. Therefore, a simple weighing method was developed to adjust the seasonal coefficient of the mean chair insulation value (0.75 in summer, 1.0 in transition, and 1.25 in winter). Furthermore, a simple model was established for calculating the overall clothing level for a seated person. The model was validated using data measured in this experiment and other external sources, with a minimum prediction mean error of 1.4 %. This study provides a reference for accurately acquiring the thermal insulation value of chairs for a seated person in thermal comfort studies.

Traditional versus dynamic sitting: Lumbar spine kinematics and pain during computer work and activity guided tasks

Dynamic sitting may mitigate low back pain during prolonged seated work. The current study compared pelvis and lumbar spine kinematics, pain, and work productivity, in traditional and dynamic sitting. Sixteen participants completed three 20-min blocks of computer work and activity guided tasks in a traditional office chair or backless and multiaxial rotating seat pan while kinematics were measured from accelerometers on the low back. Pain ratings were recorded on a visual analogue scale every 10 min. Similar pelvis and lumbar kinematics emerged when performing computer work in traditional and dynamic sitting. Pelvis and lumbar sagittal and frontal plane shifts and fidgets were largest for dynamic sitting in the activity guided tasks. Buttocks pain was higher in dynamic sitting, but low back pain and work productivity were unaffected. Dynamic sitting increased spine movement during activity guided tasks, without negatively impacting lumbar kinematics, low back pain, or productivity during seated computer work.

Assessing the Preservation of Lumbar Lordotic Curvature in Everyday Sitting Conditions Assessed with an Inertial Measurement System.

Background/Objectives: Lumbar lordotic curvature (LLC), closely associated with low back pain (LBP) when decreased, is infrequently assessed in clinical settings due to the spatiotemporal limitations of radiographic methods. To overcome these constraints, this study used an inertial measurement system to compare the magnitude and maintenance of LLC across various sitting conditions, categorized into three aspects: verbal instructions, chair type, and desk task types. Methods: Twenty-nine healthy participants were instructed to sit for 3 min with two wireless sensors placed on the 12th thoracic vertebra and the 2nd sacral vertebra. The lumbar lordotic angle (LLA) was measured using relative angles for the mediolateral axis and comparisons were made within each sitting category. Results: The maintenance of LLA (LLAdev) was significantly smaller when participants were instructed to sit upright (-3.7 ± 3.9°) compared to that of their habitual sitting posture (-1.2 ± 2.4°) (p = 0.001), while the magnitude of LLA (LLAavg) was significantly larger with an upright sitting posture (p = 0.001). LLAdev was significantly larger when using an office chair (-0.4 ± 1.1°) than when using a stool (-3.2 ± 7.1°) (p = 0.033), and LLAavg was also significantly larger with the office chair (p < 0.001). Among the desk tasks, LLAavg was largest during keyboard tasks (p < 0.001), followed by mouse and writing tasks; LLAdev showed a similar trend without statistical significance (keyboard, -1.2 ± 3.0°; mouse, -1.8 ± 2.2°; writing, -2.9 ± 3.1°) (p = 0.067). Conclusions: Our findings suggest that strategies including the use of an office chair and preference for computer work may help preserve LLC, whereas in the case of cueing, repetition may be necessary.

Analysis Of Work Motivation In Increasing Employee Productivity At PT PLN (Persero) ULTG Panakkukang

This study aims to analyze work motivation in increasing employee productivity at PT PLN (Persero) ULTG Panakkukang. This type of research is qualitative with data collection techniques used through observation and interviews. The object of this research is the manager and employees of PT PLN (Persero) ULTG Panakkukang, totaling 5 informants. The results of the research that can be written show that employees of PT PLN (Persero) ULTG Panakkukang are less motivated at work which has an impact on employee work productivity. This can be seen from the lack of encouragement in the form of incentives such as awards given by the company, employees feel the work given and the awards received are not balanced. The condition of the work environment that makes the lack of comfort of employees at work, because of the interaction between employees who are less harmonious and good communication so that employees are busy with their respective activities such as playing cellphones. Physical needs such as office facilities that still need attention such as office chairs and tables that have not been updated, office ac that has not been repaired, and this has an impact on the level of employee work motivation.

Unveiling the peptidases of parasites from the office chair - The endothelin-converting enzyme case study.

The emergence of high-throughput methodologies such as next-generation sequencing and proteomics has necessitated significant advancements in biological databases and bioinformatic tools, therefore reshaping the landscape of research into parasitic peptidases. In this review we outline the development of these resources along the -omics technologies and their transformative impact on the field. Apart from extensive summary of general and specific databases and tools, we provide a general pipeline on how to use these resources effectively to identify candidate peptidases from these large datasets and how to gain as much information about them as possible without leaving the office chair. This pipeline is then applied in an illustrative case study on the endothelin-converting enzyme 1 homologue from Schistosoma mansoni and attempts to highlight the contemporary capabilities of bioinformatics. The case study demonstrate how such approach can aid to hypothesize enzyme functions and interactions through computational analysis alone effectively and emphasizes how such virtual investigations can guide and optimize subsequent wet lab experiments therefore potentially saving precious time and resources. Finally, by showing what can be achieved without traditional wet laboratory methods, this review provides a compelling narrative on the use of bioinformatics to bridge the gap between big data and practical research applications, highlighting the key role of these technologies in furthering our understanding of parasitic diseases.

Postural stabilization effect of neck pillow during short-term rest in sitting position in an office chair with medium-height backrest

Postural stabilization effect of neck pillow during short-term rest in sitting position in an office chair with medium-height backrest

A novel motorized office chair causes low-amplitude spinal movements and activates trunk muscles: A cross-over trial.

Inactivity and long periods of sitting are common in our society, even though they pose a health risk. Dynamic sitting is recommended to reduce this risk. The purpose of this study was to investigate the effect of continuous passive motion (CPM) conducted by a novel motorized office chair on lumbar lordosis and trunk muscle activation, oxygen uptake and attentional control. Randomized, single-session, crossover with two periods/conditions. Twenty office workers (50% women) sat for one hour on the motorized chair, one half with CPM, the other not. The starting condition (CPM/no CPM) was switched in half of the sample. The participants were equipped with a spirometric cart, surface EMG, the Epionics SPINE system and performed a computer-based test for attentional control (AX-CPT). Outcomes were lumbar sagittal movements and posture, number of trunk muscle activations, attentional control and energy expenditure. The CPM of the chair causes frequent low-amplitude changes in lumbar lordosis angle (moved: 498 ± 133 vs. static: 45 ± 38) and a higher number of muscle activations. A periodic movement pattern of the lumbar spine according to the movement of the chair was observed in every participant, although, sitting behavior varied highly between individuals. Attentional control was not altered in the moved condition (p = .495; d = .16). Further, oxygen uptake did not increase higher than 1.5 MET. The effects of the motorized chair can be particularly useful for people with static sitting behavior. Further studies should investigate, whether CPM provides the assumed beneficial effects of dynamic sitting on the spine.

Accurate and Efficient Sitting Posture Recognition and Human‐Machine Interaction Device Based on Fabric Pressure Sensor Array and Neural Network

AbstractThis article presents a novel approach to interact with users through posture recognition, leveraging its advantages of convenience and real‐time feedback to enhance user engagement and personalized experiences. In contrast to traditional methods that rely on camera‐based posture detection, this study proposes a deep learning‐based framework for posture recognition by classifying the distribution of body pressure under different sitting positions. The system integrates a large‐area, highly flexible fabric pressure sensor array into the chair, which collects data on posture‐specific pressure patterns for training and identification purposes. A deep learning algorithm, specifically the LeNet architecture, is employed to classify 49 different sitting positions based on angular variations, including body tilt to the left or right, standard posture, and forward or backward leaning. The proposed approach achieves an impressive accuracy rate of 99.86%. Furthermore, the application of this posture recognition system in VR devices enables intelligent chair control for VR games. This research provides strong support for future advancements in chair design and human‐computer interaction technologies, enhancing ergonomic designs in various domains such as automotive seats, office chairs, and medical seating, while simultaneously improving user comfort and well‐being.

The Effect of Environmental and Ergonomic Stimuli of the Work Environment on Employees’ Behavior by the Mediating Role of General Health

Objectives: Considering the importance of employees' behavior in service organizations and its significant impact on their success and failure, the present study investigates the environmental and ergonomic factors affecting the mental health and behavior of employees in one of the branches of Islamic Azad University.&#x0D; Methods: The present study is applied in terms of purpose and descriptive-correlational in terms of data gathering and analysis. The statistical population of the study includes: 315 employees of Rasht Branch of Azad University, out of them 196 people were selected by random sampling method and the necessary data were collected using a questionnaire. Structural equation modeling and SMART PLS3 software were used to test the hypotheses.&#x0D; Results: According to the findings, workplace layout affects on use of work equipment (0.389), use of office chair (0.252) and environmental conditions (0.538), but the effect of workplace layout on the posture of employees was not confirmed in 5 percent significance level. Also, the effect of posture (0.586), layout (0.440), work equipment (0.458), office chair (0.345) and environmental conditions (0.550) on public health and also the effect of general health (0.690) and environmental conditions (0.158) on employees’ behavior is significant. Examining the indirect relationships of the research model also shows that workplace layout affects employee behavior through the general health and environmental conditions. Workplace layout influences employees’ behavior through work equipment, office chair, environment conditions and general health.&#x0D; Conclusion: The indirect effect of workplace layout on employees’ behavior through public health has the highest impact (0.304), therefore, making policies for the general health, can improve employees’ behavior.

Knitted Heating Mats

Abstract The paper deals with conceptual designs and research on flexible knitted heating mats differing in construction from textile heaters on low-elastic woven or nonwoven-foil substrates. Two variants of heating mats with elasticity from 100 to 300 % of relative elongation were designed and manufactured using knitting technology. The heating elements of the mats were parallel-connected sets of electrically conducted carbon threads and synthetic threads coated with silver. With considerable elongation in the range of 210÷270 % no damage was observed to the heating elements and resistance changes during the stretching process equaled from 0.015 to 0.22 Ω/% of elongation. The optimum power of the knitted heater in the range from 16 to 41 W, with high thermal efficiency for a 12 V supply voltage, was obtained thanks to proper density of the electrically conductive threads (resistors) and the appropriate structure of the knitted fabric. The surface temperature of the heater can be adjusted from 34 to 43 °C, which corresponds to human thermal comfort. One of the variants of the knitted heaters was applied in the construction of the seat and backrest of an office chair.

Comparisons of lumbosacral kinematics among non-specific chronic low back pain subgroups and healthy during prolonged sitting: A cross-sectional observational study

BackgroundThe literature has suggested a variety of postural changes of the spine that possibly contribute to the increase in back pain during sitting in persons with non-specific chronic low back pain (NS-CLBP). However, the heterogeneity of NS-CLBP persons has made the ability to attribute pain increase to a particular sitting posture very difficult. Therefore, the purpose of this study was to compare lumbosacral kinematics and their roles in pain increase among homogenous NS-CLBP subgroups and healthy controls over a 1-h sitting period. MethodsTwenty NS-CLBP subjects with motor control impairment [10 classified as having flexion pattern (FP) disorder, and 10 with active extension pattern (AEP) disorder], and 10 healthy controls participated in the study. Subjects underwent a 1-h sitting protocol on a standard office chair. Lumbosacral postures including sacral tilt, third lumbar vertebrae (L3) position, and relative lower lumbar angle were recorded using two-dimensional inclinometers over the 1-h period. Perceived back-pain intensity was measured using a visual analog scale every 10 min throughout the sitting period. ResultsAll study groups (FP, AEP and healthy controls) significantly differed from each other in the measured lumbosacral kinematics at the beginning as well as at the end of the sitting period (p ≤ 0.05). Only the NS-CLBP subgroups showed significant changes in the lumbosacral kinematics across the 1-h sitting period (p < 0.01), and that the directions of change occurred toward end spinal postures (lumbar kyphosis for FP subgroup and lumbar lordosis for the AEP subgroup). In addition, both NS-CLBP subgroups reported a similarly significant increase in pain through mid-sitting (p < 0.001). However, after mid-sitting, the AEP subgroup reported much less increase in pain level that was accompanied by a significant decrease in the lumbar lordotic postures (p = 0.001) compared to FP subgroup. ConclusionThe present study's findings suggest that each NS-CLBP subgroup presented with differently inherent sitting postures. These inherently dysfunctional postures coupled with the directional changes in the lumbosacral kinematics toward the extreme ranges across the 1-h sitting period, might explain the significant increase in pain among subgroups.

Effect of sitting posture on the thermal insulation of modern office chairs

Effect of sitting posture on the thermal insulation of modern office chairs

Mechanical work and energy of sit-to-stand and stand-to-sit transitions performed with traditional and dynamic office chair designs.

Adherence to sit-stand workstation usage has been shown to decrease post-intervention, with the reported reasons related to fatigue, cumbersome workstation adjustments, and focus. To characterize the mechanical work and total energy required to perform transitions from a traditional office chair and a dynamic chair designed specifically for sit-stand workstations. The whole-body, thigh, and shank centre-of-mass (CoM) were evaluated. Fifteen participants (8 male; 7 female) performed three intermittent sit-to-stand and stand-to-sit transitions from the traditional and dynamic chairs. Kinematic data of the trunk, pelvis, and lower extremities were collected using an optoelectronic motion capture system and triaxial accelerometers. The change in total energy and work between the sitting and standing postures were evaluated for each CoM point. Lumbar spine range-of-motion was further assessed between chair conditions. Chair designs facilitated opposite work and energy responses for a given transition. Transitions performed from the dynamic chair reduced the work and total energy of the whole-body CoM, by ±8.5J and ±214.6J (p < 0.001), respectively. The work and energy of the thigh CoM differed within transitions (p < 0.001), but the positive and negative components were similar between chairs (work =±0.18J, energy =±0.55J). The dynamic chair increased the total energy (±38.3J, p < 0.001) but not the work of the shank CoM (±1.1J, p≥0.347). The required mechanical work and energy of sit-to-stand and stand-to-sit transitions was modified by chair design. These outcomes have the potential to address identified reasons for the disuse of sit-stand workstations.

System Approach for Characterizing and Evaluating Factors for Occupational Health Impacts Due to Nonfatal Injuries and Illnesses for the Use in Life Cycle Assessment.

Occupational injuries and illnesses are major risk factors for human health impacts worldwide, but they have not been consistently nor comprehensively considered in life cycle impact assessment (LCIA) methods. In this study, we quantified occupational health impacts as disability-adjusted life years (DALYs) for nonfatal injuries and illnesses in all US industries. We further applied an economic input-output model of the US economy to develop a new data set of characterization factors (CFs) that links direct and indirect occupational health impacts to product life cycle final demand. We found that the CF data set varies significantly by industry, ranging from 6.1 to 298 DALYs per billion dollars. About 20% of final demand in the US economic system contributes nearly 50% of the total impacts of occupational health, suggesting occupational health impacts are concentrated in a small portion of industries. To verify the feasibility of the CFs and demonstrate their importance, we included a case of an office chair. The occupational health impacts caused by nonfatal injuries and illnesses during the production of an office chair are of the same order of magnitude as those caused by chemical emissions across the chair's life cycle, with 1.1 × 10-5 and 1.4 × 10-5 DALYs per chair, respectively. Results and data sets derived from this study support the integration of occupational health impacts with LCIA methods.

Office Seat Design And Analysis

An office seat, or work chair, is a type of chair that is designed for use at a desk in an Office. Usually a padded back, a padded seat, arm that enables us to rest and the back of the chair has wheels. Office seats presently, in offices, hospitals and homes, in many places It is a product we come across. The thing that makes this product so popular compared to the chair casual/comfortable and has provided the ability to move that is. Related to working life according to the results of the review, especially for employees in small and medium-sized organizations they spend more than sitting for the sleep period. For this reason, and 19. the emergence century the reason increase employee productivity by increasing employees the time to sit office chair and study chair was named as product due. In this study two studymodels in standards sizes we use in our daily lives SOLIDWORKS student version of the program reviewed in the design of the seat. Also this ANSYS student version of the program in the analysis of the designs was carried out.

Poster 372: Women in Leadership in Orthopaedic Sports Medicine Societies Throughout the World

Objectives: The proportion of women in orthopaedic surgery is low compared to other specialties, despite a equal numbers of women and men entering the field of medicine. This gender disparity persists across various aspects of orthopaedic sports medicine. The purpose of this study was to characterize the number of women in leadership positions in orthopaedic sports medicine and arthroscopy societies throughout the world and compare the percentages of women vs men in leadership positions. Methods: Publicly available websites for orthopaedic sports medicine societies throughout the world were evaluated during March 2022. Non-surgical sports medicine societies were excluded, as were societies lacking publicly available leadership information. Data were collected as listed on the websites, and categorized into Board of Directors, Executive Committee, Office, Council (all typically included Presidential line, Vice-President, Treasurer, Secretary, or other specific high-ranking members), and Committee Chairs (excluded general committee members). Results: Of the 46 societies, 16 (34.8%) were in Europe, 10 (21.7%) in Asia, 6 (13.0%) in South America, 5 (10.9%) in North America, 3 in the Middle East (6.5%), 2 in Africa (4.4%), 2 in Australia (4.4%), and 2 were international organizations (4.4%). Four countries had more than one orthopaedic sports medicine society: Argentina, Israel, Australia, and Mexico. As represented by Figure 1, the Board of Directors were comprised of 2.5% women (4/161), the Executive Committees were 7.1% women (11/154), Committee Chairs were 9.4% women (13/138), Officers were 15.8% women (3/19), Councils were 5.9% women (1/17), and Spokespersons were 16.7% women (1/6). For the Board of Directors, North America and Europe led in women representation with 4.0% and 3.8%, South America had 2.0%, and societies from the Middle East and Asia reported no women. Regarding Executive Committee, North America had the most women with 27.8%, and the remaining regions ranged from 0.0-7.9%. For Committee Chairs, both European and International societies had around 8% women in leadership (8.0% and 7.7%, respectively), yet North America had double with 16.7% women. Of the regions reporting Officers, Asia and Europe had similar percentages (16.7% and 18.2%), whereas Australia reported zero women in office. Only one region reported electing a Council and two regions listed Spokespersons. Conclusions: This study highlights the gender disparities in leadership positions in orthopaedic sports medicine societies throughout the world. The visibility of women in high-ranking positions may contribute to the interest of women and other minorities in the field of sports medicine and help improve diversity. Future studies should investigate factors contributing to the paucity of women in leadership positions and identify ways to increase the proportion of women in orthopaedic sports medicine.

IOT Based Smart Chair to Help with Back Pain

Abstract: This Poor sitting posture is a common cause of low back pain, as it places excessive pressure on muscles and discs. To address this issue, smart office chairs have been developed using IoT, wireless communication, sensing, and intelligent control technologies. This paper proposes and implements a system for detecting incorrect sitting positions using a smart chair equipped with two tactile pressure sensor mats, vibration actuators, NodeMCU , a data acquisition module, and a cloud server. The system notifies users of incorrect sitting positions through visual and vibration feedback, which is received through a mobile application. Simple rules were defined to process sensor data to recognize wrong sitting postures, and the data collected from smart chairs were stored in a MongoDB database using a private cloud solution from QNAP. The Node-RED application was proposed for the entire logic implementation.

Comparing the Effects of Ergonomic and Standard Office Chairs on Trunk Muscle Activation

Background and Purpose: Musculoskeletal disorders (MSD) are one of the most common health problems faced by individuals who sit for prolonged periods. The sitting design of office chairs has recently become an important aspect in preventing the MSD. The aim of this study is to determine the effect of different chair types on trunk muscle activation.&#x0D; Methods: Fifteen participants (age 22.92 ± 3.40 years) were included in the study. Participants’ muscle activations were assessed with the sEMG device while sitting and typing on the computer for one hour. &#x0D; Results: When two different types of chairs were compared, in the first 10 minutes, % MVC difference was observed only in the TES (p