A study of classroom seat (dis)comfort: Relationships between body movements, center of pressure on the seat, and lower limbs' sensations

Ergonomic design of computer laboratory furniture: Mismatch analysis utilizing anthropometric data of university students

Many studies have shown that ergonomically designed furniture improves productivity and well-being. As computers have become a part of students' academic lives, they will continue to grow in the future. We propose anthropometric-based furniture dimensions that are suitable for university students to improve computer laboratory ergonomics. We collected data from 380 participants and analyzed 11 anthropometric measurements, correlating them with 11 furniture dimensions. Two types of furniture were found and studied in different university computer laboratories: (1) a non-adjustable chair with a non-adjustable table and (2) an adjustable chair with a non-adjustable table. The mismatch calculation showed a significant difference between existing furniture dimensions and anthropometric measurements, indicating that 7 of the 11 existing furniture dimensions need improvement. The one-way ANOVA test with a significance level of 5% also showed a significant difference between the anthropometric data and existing furniture dimensions. All 11 dimensions were determined to match students' anthropometric data. The proposed dimensions were found to be more compatible and showed reduced mismatch percentages for nine furniture dimensions and nearly zero mismatches for seat width, backrest height, and under the hood for both males and females compared to the existing furniture dimensions. The proposed dimensions of the furniture set with adjustable seat height showed slightly improved match results for seat height and seat-to-table clearance, which showed zero mismatches compared with the non-adjustable furniture set. The table width and table depth dimensions were suggested according to Barnes and Squires' ergonomic work envelope model, considering hand reach. The positions of the keyboard and mouse are also suggested according to the work envelope. The monitor position and viewing angle were proposed according to OSHA guidelines. This study suggests that the proposed dimensions can improve comfort levels, reducing the risk of musculoskeletal disorders among students. Further studies on the implementation and long-term effects of the proposed dimensions in real-world computer laboratory settings are recommended.

Psychometric properties of the Iranian version of the wheelchair seating discomfort assessment tool (WcS-DAT) - section II: a revised two-dimensional structure of comfort and discomfort to improve inclusive design practice

PURPOSE

The objectives of the study were to: 1) validate the Wheelchair Seating Discomfort Assessment Tool (WcS-DAT - section II) in Iran, and 2) to determine whether or not the items on the scale address just one dimension (e.g., discomfort).

METHODS

A descriptive-methodological study was performed among 109 (76 males and 33 females) full-time wheelchair users, aged 12-70 years in Tabriz, Iran. To develop the revised Iranian version of the WcS-DAT - section II, a standard "forward-backward" method was in the first step. Then, the content validity and construct validity of the tool was assessed based on feedback from an expert panel and factor analyses (exploratory and confirmatory), respectively. Sensitivity (using ceiling/floor effect), internal consistency (using Cronbach's α), and test-retest reliability (using Intraclass Correlation Coefficient - ICC) were also evaluated.

RESULTS

Results established content validity, sensitivity, internal consistency (values of Cornbrash's α: 0.79-0.82), and test-retest reliability (values of ICC: 0.79-0.93) of the Iranian WcS-DAT - section II. Factor analyses revealed a two-factor structure (comfort and discomfort), for the scale, and thus confirmed its construct validity.

CONCLUSIONS

The findings suggest that the Iranian version of WcS-DAT- section II is a reliable and valid tool for the evaluation of wheelchair seating comfort and discomfort in the Iranian population. The revised two-factor model of comfort/discomfort has potential implications for inclusive design research and practice.

Alterations in Physical Demands During Virtual/Augmented Reality-Based Tasks: A Systematic Review

The digital world has recently experienced a swift rise in worldwide popularity due to Virtual (VR) and Augmented Reality (AR) devices. However, concrete evidence about the effects of VR/AR devices on the physical workload imposed on the human body is lacking. We reviewed 27 articles that evaluated the physical impact of VR/AR-based tasks on the users using biomechanical sensing equipment and subjective tools. Findings revealed that movement and muscle demands (neck and shoulder) varied in seven and five studies while using VR, while in four and three studies during AR use, respectively, compared to traditional methods. User discomfort was also found in seven VR and three AR studies. Outcomes indicate that interface and interaction design, precisely target locations (gestures, viewing), design of virtual elements, and device type (location of CG as in Head-Mounted Displays) influence these alterations in neck and shoulder regions. Recommendations based on the review include developing comfortable reach envelopes for gestures, improving wearability, and studying temporal effects of repetitive movements (such as effects on fatigue and stability). Finally, a guideline is provided to assist researchers in conducting effective evaluations. The presented findings from this review could benefit designers/evaluations working towards developing more effective VR/AR products.

A Systematic Review on Lower-Limb Industrial Exoskeletons: Evaluation Methods, Evidence, and Future Directions

Industrial tasks that involve frequent sitting/standing transitions and squatting activities can benefit from lower-limb industrial exoskeletons; however, their use is not as widespread as their upper-body counterparts. In this review, we examined 23 articles that evaluated the effects of using Wearable Chair (WC) and Squat-assist (SA) exoskeletons. Evaluations mainly included assessment of muscular demands in the thigh, shank, and upper/lower back regions. Both types of devices were found to lessen muscular demands in the lower body by 30-90%. WCs also reduced low-back demands (~ 37%) and plantar pressure (54-80%) but caused discomfort/unsafe feeling in participants. To generalize outcomes, we suggest standardizing approaches used for evaluating the devices. Along with addressing low adoption through design upgrades (e.g., ground and body supports/attachments), we recommend that researchers thoroughly evaluate temporal effects on muscle fatigue, metabolic rate, and stability of wearers. Although lower-limb exoskeletons were found to be beneficial, discrepancies in experimental protocols (posture/task/measures) were discovered. We also suggest simulating more realistic conditions, such as walking/sitting interchangeability for WCs and lifting loads for SA devices. The presented outcomes could help improve the design/evaluation approaches, and implementation of lower limb wearable devices across industries.

A multidimensional sensory evaluation model to investigate the (dis)comfort of body parts in a supine sitting position during a lunch break

Employees who work long hours frequently complain of muscle fatigue caused by prolonged sitting. As a result, products that assist them when resting in a chair in a reclining position, in order to relieve fatigue and improve comfort are required. To ensure that the new product works as intended, a usability test based on prototyping must be developed. The research process was divided into three stages: firstly, the development of the perception assessment questionnaire; secondly, a validated factor analysis (CFA) was conducted on the perception assessment data of 26 subjects and the measurement model was fitted to verify the reliability and validity of the questionnaire; finally, the sEMG technique was used to verify the comfort level of 21 subjects. Based on usability experiments and an exploration of human factor relationships, this study develops a prototype testing model, which focuses on the comfort perception of body parts, as a means of promoting innovation in the design and manufacturing industry.

Postural strategies among office workers during a prolonged sitting bout

Sedentary behavior has increased steadily over prior decades, primarily due to increased computer use at work and at home. The total sedentary time per day has been associated with increased risk of cardiometabolic diseases; increased sitting time at work has been associated with musculoskeletal discomfort particularly in the low back. Office workers spend many hours sitting, thus efforts to increase movement through changes of posture (sit to stand) or moving while sitting have been proposed as ways to mitigate the negative effects of prolonged sitting. Yet, few studies have investigated differences in the movement patterns of office workers while sitting performing their actual work. Therefore, the aim of this study was to characterize movement patterns during a prolonged sitting bout and to determine their association with musculoskeletal pain. Twenty-eight office workers participated in this field study that used a pressure sensitive mat to quantify seat pan pressure (4 regions) and trunk sway parameters over a 2-hour bout of computer work. Data were stratified by breakers who stood up at least once within the 2-hour test and prolongers who remained sitting throughout the test. Overall, there was a decreasing trend in trunk sway parameters (mean COP position, sway path, sway area, sway velocity, maximum displacement, and in-chair movements) over time (p < 0.05), with significant changes in sitting strategies. There were significant differences in trunk sway parameters and perceived musculoskeletal discomfort between breakers and prolongers with breakers having more consistent movement while sitting over the prolonged sitting bout (p < 0.05) and lower discomfort ratings. This may indicate that interrupting prolonged bouts of sitting with short periods of standing can maintain sitting movement patterns and reduce the development of musculoskeletal discomfort. Trunk sway monitoring and promoting periodic standing may be useful tools for maintaining in chair movements that may reduce or prevent the onset of musculoskeletal discomfort during prolonged sitting.

A hybrid approach to product prototype usability testing based on surface EMG images and convolutional neural network classification

OBJECTIVE

It is common for employees to complain of muscle fatigue when resting in a reclined position in an office chair. To investigate the physical factors that influence resting comfort in a supine position, a newly designed product was used as the basis for creating a prototype experiment and testing its efficacy in use. Subjective questionnaires were combined with surface EMG measurements and deep learning algorithms were used to identify body part comfort to create a hybrid approach to product usability testing.

METHODS

To facilitate the use of sEMG-based CNNs in human factors engineering, a subjective user assessment was first conducted using a combination of body mapping and an impact comfort scale to the screen which body parts have a significant impact effect on comfort when using the prototype. A control group (no used) and an experimental group (used) were then created and the body parts with the most significant effects were measured using sEMG methods. After pre-processing the sEMG signal, sMEG feature maps were obtained by mean power frequency (MPF) and linear regression was used to analyze the comforting effect. Finally, a CNN model is constructed and the sMEG feature maps are trained and tested.

RESULTS

The results of the experiment showed that the user's subjective assessment showed that 10 body parts had a significant effect on comfort, with the right and left sides of the neck having the highest effect on comfort (4.78). sEMG measurements were then performed on the sternocleidomastoid (SCM) of the left and right neck. Linear analysis of the measurements showed that the control group had higher SCM fatigue than the experimental group, which could also indicate that the experimental group had better comfort. The final CNN model was able to accurately classify the four datasets with an accuracy of 0.99.

CONCLUSION

The results of the study show that the method is effective for the study of physical comfort in the supine sitting position and that it can be used to validate the comfort of similar products and to design iterations of the prototype.

Anthropometric perspective to classroom furniture ergonomics and the need for standards in Nigerian schools

BACKGROUND: Classroom furniture designs have been implicated in musculoskeletal disorders among school age persons due to high level mismatches between the furniture dimensions and users’ anthropometrics. OBJECTIVE: The objective of the study was to analyze classroom furniture ergonomics at selected primary, secondary and tertiary educational institutions in Nigeria and to understand if there are noticeable patterns in the match/mismatch. METHOD: Anthropometric measures relevant to furniture design were obtained from primary and secondary school children as well as from university undergraduates. The dimensions of classroom furniture available to the participants were also taken and an assessment of the suitability of the furniture was completed. RESULT: The ergonomic evaluation of the classroom furniture available to the study participants revealed enormous discrepancies between the furniture dimensions and the anthropometric measures of the users. In addition, a pattern was observed in the way the matches/mismatches occurred. The furniture dimensions that matched majority of the users tend to match across the three categories and those that did not match majority of the students, also followed the same pattern. CONCLUSION: The study presents remarkably high levels of mismatches between classroom furniture and users’ anthropometrics and therefore calls for a review of the policies for classroom furniture design in Nigeria, if at all any policy exists.

Identification of Workplace Social Sustainability Indicators Related to Employee Ergonomics Perception in Indonesian Industry

Sustainability indicators have provided a breakthrough for companies to assess their performance in supporting corporate sustainability. There is no standard framework for these support-defining indicators to conduct a social sustainability performance assessment. There is a limitation of quantitative social sustainability indicators appropriate for performing ergonomic concept assessments. Ergonomics, as a field concerning people and their interactions with the environment, in particular, the workplace, can play a role in social sustainability, besides its conventional approach of workplace re-engineering. Three major areas of ergonomics were analyzed. The indicators were established based on a review of the literature and confirmed using a factor analysis that covered all major aspects of workplace ergonomics. The factor analysis aimed to reduce the complexity of workplace social sustainability indicators related to ergonomics. The final result integrated 73 indicators into 17 indicators based on three major areas of ergonomics. The findings showed that the best workplace social sustainability indicators were divided into five factors: employee well-being, safety concerns, workplace comfort, musculoskeletal health, and environmental concerns. It would be very beneficial for the industry and the government to support corporate social sustainability and the global sustainability index.

A Resource Constrained Neural Network for the Design of Embedded Human Posture Recognition Systems

A custom HW design of a Fully Convolutional Neural Network (FCN) is presented in this paper to implement an embeddable Human Posture Recognition (HPR) system capable of very high accuracy both for laying and sitting posture recognition. The FCN exploits a new base-2 quantization scheme for weight and binarized activations to meet the optimal trade-off between low power dissipation, a very reduced set of instantiated physical resources and state-of-the-art accuracy to classify human postures. By using a limited number of pressure sensors only, the optimized HW implementation allows keeping the computation close to the data sources according to the edge computing paradigm and enables the design of embedded HP systems. The FCN can be simply reconfigured to be used for laying and sitting posture recognition. Tested on a public dataset for in-bed posture classification, the proposed FCN obtains a mean accuracy value of 96.77% to recognize 17 different postures, while a small custom dataset has been used for training and testing for sitting posture recognition, where the FCN achieves 98.88% accuracy to recognize eight positions. The FCN has been prototyped on a Xilinx Artix 7 FPGA where it exhibits a dynamic power dissipation lower than 11 mW and 7 mW for laying and sitting posture recognition, respectively, and a maximum operation frequency of 47.64 MHz and 26.6 MHz, corresponding to an Output Data Rate (ODR) of the sensors of 16.50 kHz and 9.13 kHz, respectively. Furthermore, synthesis results with a CMOS 130 nm technology have been reported, to give an estimation about the possibility of an in-sensor circuital implementation.

Designing School Tables and Chairs based on Anthropometry of Elementary School Students in Surabaya

 Introduction: School tables and chairs are needed amongst many other facilities which support the teaching and learning activities. Uncomfortable tables and chairs can cause health problems. The purpose of this study is to design school table and chair sizes in accordance with anthropometry of elementary school students, so the tables and chairs do not cause health problems for children. Methods: The population used in this study was 72 students of elementary school students in Surabaya, and the sample size was 61 students. The sampling method used in this research was a simple random sampling. The anthropometric data measured were shoulder height in the sitting position, elbow height in the sitting position, popliteal-buttock length, knee height, popliteal height, shoulder width, and distance from elbow to fingertips. Meanwhile, the dimensions of tables and chairs measured were chair height, chair width, back length, back height, table height, table width, and underneath desk height. Results: The results of the research show that the sizes of existing tables and chairs are mismatched with student anthropometry. There are 7 dimensions of proposed table and chair sizes which are based on anthropometric data. Specifically, the chair height is 33.25 cm, chair width is 33.25 cm, backrest length is 46.50 cm, backrest height is 49.60 cm, table height is 56.85 cm, table width is 39.05 cm, and underneath desk height is 47 cm. Conclusion: The sizes of existing tables and chairs still need improvement in all dimensions based on the students’ anthropometric measurements.Keywords: anthropometry, chair, elementary school students, table 

Identifying factors that influenced wellbeing and learning effectiveness during the sudden transition into eLearning due to the COVID-19 lockdown

BACKGROUND

The sanitary emergency due to COVID-19 virus obliged people to face up several changes in their everyday life becauseWorld Health Organisation (WHO) guidelines and countries' Health Systems imposed lockdown of activities and social distancing to flatten the infection curve. One of these rapid changes involved students and professors that had to turn the traditional "in presence" classes into online courses facing several problems for educational delivery.

OBJECTIVES

This work aimed to investigate the factors that affected both teaching/learning effectiveness and general human comfort and wellbeing after the sudden transition from classrooms to eLearning platforms due to COVID-19 in Italy.

METHODS

A workshop, involving students and experts of Human Factors and Ergonomics, has been performed to identify aspects/factors that could influence online learning. Then, from workshop output and literature studies, a survey composed of two questionnaires (one for students and one for teachers) has been developed and spread out among Italian universities students and professors.

RESULTS

700 people answered the questionnaires. Data have been analysed and discussed to define the most important changes due to the new eLearning approach. Absence of interactions with colleagues and the necessity to use several devices were some of the aspects coming out from questionnaires.

CONCLUSIONS

The study shows an overview of factors influencing both teaching/learning effectiveness and general human comfort and wellbeing. Results could be considered as a basis for future investigation and optimization about the dependencies and correlations among identified factors and the characteristics of the products/interaction/environment during eLearning courses.

A method for postural critical factors checking: The case of library chairs

BACKGROUND

According to ergonomic researches regarding a good sitting posture, it is essential to ensure a natural back-curve in order to prevent musculoskeletal disorders. A brief observation among the Scientific Technology Library inside the University of Salerno showed that students used to complain about neck and lumbar pain, especially after a study day.

OBJECTIVE

On the light of this background, a sitting posture comfort analysis had been performed on chairs inside the library to check the critical factors that influence the postural comfort and, consequently, the learning.

METHODS

A prolonged sitting posture, that is common during the daily study activity, had been simulated with fifteen volunteer students performing 1-hour tests (divided into four 15-minutes tasks). Subjective perceptions had been gathered through questionnaires rating on a 5-point Comfort scale, both the expected comfort at the beginning of the experiment and the Localized Postural Comfort at the end of each task have been investigated. Then, postural angles had been gathered through photographic acquisition and Kinovea®. CaMAN software had been used to calculate the objective (dis)comfort indexes. Finally, subjective and objective data had been statistically processed and compared.

RESULTS

Lumbar area scored the lowest perceived comfort while the perceived comfort was independent of participants and tasks, but dependent on time.

CONCLUSIONS

After this comfort-driven analysis, critical factors of the chair-design were checked, and a proposal for a future re-design was hypothesized.

Study of the relationships between articular moments, comfort and human posture on a chair

BACKGROUND

One of the aspects that influences the sitting comfort is the distribution of the pressure applied to the skin by the seat surface. In the scientific literature, many studies show experimental activities in order to evaluate the influence of pressure distribution at the seat-human interface on the comfort evaluation. The main limitation in seat design is based on the difficulties to predict the contact pressures distribution without prototypes because of the complex interaction among body muscles, wearing, human's anthropometric characteristics, shape and materials of the seat. Moreover, the same human can assume different postures on the same seat, and different people, seated on the same chair, can assume different postures even if they have the same anthropometric percentile.

OBJECTIVE

The aim of this study is to propose a mathematical model evaluating interaction loads between human segments and seat segments.

METHOD

In this model, a human body represented by 8 segments is placed on a 6 segments seat with posture dependent on seat segments and on position of the coccyx on seat and feet on floor. Human segments can be configured in length and weight and friction between body and seat is considered. A model validation study based on an experimental comparison with contact pressures is also presented.

RESULTS

The experiment showed that there is a remarkable recursion of some stress values of the articular joints of the pelvis, hip and knee. By imposing these values in the calculation model, it is possible to determine, for each chair configuration, which postures will be assumed by a person, and to make a preliminary assessment of the level of comfort possible.

School combo-desk comfort assessment: A method for weighing postural factors that affect the overall perceived comfort

BACKGROUND

In recent years, a growing interest in ergonomics and comfort perception in secondary schools and universities can be detected, to go beyond the UNI-EN regulations and understanding how practically improve students' perceived comfort during lessons.

OBJECTIVE

This study aimed to analyse the (dis)comfort perceived by students while sitting in a combo-desk during lessons; it proposed a method for understanding and weighing the influence of postural factors on overall (dis)comfort.

METHODS

Twenty healthy students performed a random combination of three different tasks in two sessions - listening, reading on a tablet and writing. Subjective perceptions were investigated through questionnaires, in which the expected and the overall comfort were evaluated; postural angles were gathered by processing photos through Kinovea® software and were used for the virtual-postural analysis, using a DHM (Digital Human Modelling) software; statistical analysis was used to investigate the influence of subjective comfort of each body part on the overall perceived comfort.

RESULTS

The statistical correlations were used to perform an optimization problem in order to create a general law to formulate the overall comfort function, for each task, as a weighted sum of the comfort perceived in each body part. The test procedure, additionally, evaluated the influence on comfort over time. The results showed how the upper back and the task-related upper limb are the most influencing factors in the overall comfort perception.

CONCLUSIONS

The paper revealed a precise and straightforward analysis method that can be easily repeated for other design applications. Obtained results can suggest to designers easy solution to re-design the combo-desk.

Review of Measuring Microenvironmental Changes at the Body-Seat Interface and the Relationship between Object Measurement and Subjective Evaluation

Being seated has increasingly pervaded both working and leisure lifestyles, with development of more comfortable seating surfaces dependent on feedback from subjective questionnaires and design aesthetics. As a consequence, research has become focused on how to objectively resolve factors that might underpin comfort and discomfort. This review summarizes objective methods of measuring the microenvironmental changes at the body–seat interface and examines the relationship between objective measurement and subjective sensation. From the perspective of physical parameters, pressure detection accounted for nearly two thirds (37/54) of the publications, followed by microclimatic information (temperature and relative humidity: 18/54): it is to be noted that one article included both microclimate and pressure measurements and was placed into both categories. In fact, accumulated temperature and relative humidity at the body–seat interface have similarly negative effects on prolonged sitting to that of unrelieved pressure. Another interesting finding was the correlation between objective measurement and subjective evaluation; however, the validity of this may be called into question because of the differences in experiment design between studies.

Developing a Multi-Criteria Decision Making approach to compare types of classroom furniture considering mismatches for anthropometric measures of university students

The mismatch between students’ anthropometric measures and school furniture dimensions have been investigated in many countries. In Iran, collegians spend at least a quarter of the day hours at university in the sitting position, so it is essential to evaluate furniture mismatch among university students. In Iranian universities, the use of chairs with an attached table is widespread, while the study of mismatches in these chairs among the collegian community is rare. This study was aimed to compare and rank different classroom furniture types based on the mismatch between collegians’ anthropometric measures and the dimensions of classroom furniture among Industrial Engineering students by developing a Multi-Criteria Decision Making approach in an integrated Methodology. The sample consisted of 111 participants (71 males, 40 females). Ten anthropometric measures were gathered, together with eight furniture dimensions for four types of chairs. Mismatch analyses were carried out using mismatch equations, and the Simple Additive Weighting method was used as a base method to solve the decision-making problem. The results indicated that Underneath Desk Height and Seat to Desk Clearance showed the highest levels of the match, while Seat Width presents the highest levels of low mismatch. According to the results, Type 1 and Type 3 were the best current classroom furniture. The Sensitivity Analysis was performed in two ways: changing the weights of criteria in nine scenarios and comparing the results with five other MCDM methods. The proposed MCDM approach can be used widely in furniture procurement processes and educational environments.

The effect of furniture intervention on the occurrence of musculoskeletal disorders and academic performance of students in North-West Nigeria

BACKGROUND

Mismatch between classroom furniture and the students' anthropometry have been identified as a major cause of musculoskeletal disorders (MSDs) among students. Such discomforts can affect students' performance.

OBJECTIVE

This paper is aimed at investigating the prevalence of MSDs and the effect of furniture intervention among students of tertiary institutions in Northwest Nigeria.

METHODS

The Cornell's MSD questionnaire was used to investigate the prevalence of MSDs in twelve body regions of students aged between 16 and 25 years. Eleven students' anthropometric dimensions were also measured and used to compute the ergonomically compliant furniture dimensions for the participants. A new set of furniture was introduced, and the questionnaire was used to investigate if the intervention made was significant or not. The academic performance of some of the students before and after the intervention was analyzed using the t-test statistical technique.

RESULT

None of the furniture in use was suitable for the majority of the students. MSDs prevalence ranges from 14% to 67.3% among the body regions with the students reporting that low back pain is the most prevalent (67.3%), severe (19.4%) and interfering with their studies (15.8%). The intervention also reduced MSDs in all body regions except at the upper arm and the right side of the forearm. Only sitting, knee, and popliteal heights were significantly associated with MSD occurrence. There was also a significant improvement in the students' academic performance after the intervention (t = -3.239, p = 0.002).

CONCLUSION

The limited success of the intervention is an indication of the need to carry out a more holistic intervention that incorporates other inputs such as continuous enlightenment and classroom facility design.

Comfortable seating: The influence of seating comfort and acoustic comfort on customers' experience of hospitality in a self-service restaurant

Does comfort in a restaurant influence people's experienced hospitality? Effects of seating comfort and acoustic comfort on the experience of hospitality were examined by means of a 2 x 2 between subjects experiment among 262 customers of a self-service restaurant, using the EH-scale measuring the experiential factors care, comfort and inviting. In line with theory on embodiment, MANOVA and mediation analysis showed that comfortable seating positively influences mental comfort, which subsequently increases the experience of hospitality (comfort factor). Extra ambient sound (acoustic discomfort) cancels out this effect. Also, people's desire to sit matters: people with a low desire to sit interpret comfortable seats as more caring instead of comfort. Regarding the discussion on (dis)comfort: seating comfort, not discomfort, accounted for the effects. Altogether, the hospitality experienced in a restaurant may be enhanced by offering comfortable seats, making customers feel more comfortable, physically and mentally.