Objective Individuals performance at the workplace is affected by different adopted postures. Sitting postures are mostly used during office work. Improper sitting postures may cause muscle fatigue and discomfort in the spine and also result in mental workload. Poor posture may result in human errors and delay in information processing. Previous studies have demonstrated the relationship between static sitting postures and cognitive factors such as reaction time to an auditory stimulus. Also, some recent studies have demonstrated the effect of static postures on cognitive performance. To our knowledge, none of the studies had considered the sitting and standing postures effects on cognitive performance simultaneously. The aim of this study was to evaluate cognitive performance during three different static working postures: standard sitting, standing, and self-selected sitting postures. Materials & Methods This semi-experimental design study was conducted on the twenty-nine healthy students (aged 20-30 years). The non-probability sampling method was selected. All participants provided their written informed consent. Participants with no musculoskeletal disorders, heart disease, spine surgery, and history of depression and stress were selected. Their depression status and level of stress were measured using Beck questionnaire. The study was approved by the Ethics Committee of University of Social Welfare and Rehabilitation Sciences. Subjects performed complex Stroop test and typing activity in an office-like laboratory setting at the University of Social Welfare and Rehabilitation Sciences. Stroop test lasted about 9-12 minutes, and a typing task was also designed for approximately 5 minutes for all subjects. Three random postures were selected based on common postures used in the office. The effects of the postures (standard standing, standard sitting, and self-selected sitting posture) on dependent variables such as total test duration and reaction time to congruent and incongruent stimulus, number of typing words and number of typing error were assessed with Repeated Measures ANOVA. To examine the differences between groups, the paired t-test was used. Results The results demonstrated that reaction time measure and number of typing error (accuracy) were affected by postures (P=0.001). Post hoc analysis demonstrated that reaction time was significantly different between self-selected sitting posture and standard sitting posture (P=0.001), self-selected sitting posture and standard standing posture (P=0.043), standard sitting posture and standard standing posture (P=0.001). With considering the average amount of reaction time to congruent and incongruent cases, it was observed that there is less reaction time in the standardized sitting posture (M=628.67 ms) compared to the self-selected sitting posture (M=689.41 ms) and standard standing posture (M= 675.16 ms). Also, among the three postures studied a significant difference was observed in the number of typing error words (P=0.001). The number of typing error ...
Operator's role in industrial control centers takes place in time, which is one of the most important determinants of whether an expected action is going to be successful or not. In certain situations, due to the complex nature of the work, the existing interfaces and already prepared procedures do not meet the dynamic requirements of operator's cognitive demands, making the control tasks unnecessarily difficult. This study was conducted to identify ergonomic issues with a specific industrial control panel, and redesign its layout and elements to enhance its usability. Task and link analysis methodologies were implemented. All essential functions and supporting operations were identified at the required trivial levels. Next, the weight of any possible link between the elements of the panel was computed as a composite index of frequency and importance. Finally, all components were rearranged within a new layout, and a computerized mockup was generated. A total of 8 primary tasks was identified, including 4 system failure handling tasks, switching between manual and automated modes, and 3 types of routine vigilance and control tasks. These tasks were broken down into 28 functions and 145 supporting operations, accordingly. Higher link values were observed between hand rest position and 2 elements. Also, 6 other components showed robust linkages. In conclusion, computer modeling can reduce the likelihood of accidents and near misses in industrial control rooms by considering the operators' misperception or mental burden and correcting poor design of the panels and inappropriate task allocation.
The most considerable result of the current study was the match between the symbol with the highest ratings and the International Organization for Standardization (ISO)-related icon in appearance. Because previous studies demonstrated a strong correlation between comprehension scores of the symbol and both semantic closeness and meaningfulness, high-level comprehensibility of the best ranked symbol is expected.
Background: Multimedia systems are of considerable benefit to the current age of information technology, being beneficial for teaching purposes. Valid and reliable tools are required to assess the effectiveness of such systems. The current study aimed to evaluate psychometric properties of the Persian version of a widely held multimedia usability measurement questionnaire. Methods and findings: The study followed a descriptive-analytical design, in which American Association of Orthopedic Surgeons (AAOS) methodology was firstly consulted to translate the original version into Persian. Content and Face Validity assessments were carried out through Lawshe's method. Construct validity was evaluated applying Exploratory and Confirmatory Factorial Analyses (EFA & CFA). Reliability was evaluated via Test-Retest methodology. A number of 357 medical university students and 10 survey instrument normalization experts were randomly invited for participation. In measuring stability Pearson coefficient was calculated for all sub-scales as (Attractiveness: 0.
Purpose: Children's interaction with the environment considerably influences their growth. To create an environment that guarantees growth and development of children's skills, children's characteristics should be considered in selecting facilities, design, and setting of child-related environments. Proper tools should be used to study the compliance of the current design of playrooms in preschool centers with the criteria of user-centered design. The research objective was to design a tool for ergonomic assessment of preschool playrooms with a cooperative approach. Methods: In this descriptive-analytical research, after reviewing the resources and visiting the place, the preliminary items of the assessment tool were extracted. Afterwards, a 43-item assessment tool was developed through group sessions attended by experts and personnel of preschool centers. The validity of the tool was assessed through content and face validity assessment tests. Reliability of the test was measured by test-retest. The data were analyzed by Excel 2010 and SPSS15. Results: Research results indicated that 7 of the 43 items had low content validity and needed to be rejected. The calculated content validity index of the final version was 72.9, which was acceptable. During the content validity assessment, minor changes were made to two items. Results of the reliability also showed that this tool is repeatable with ICC=0.99 Conclusion: Considering the research results, the proposed assessment tool is properly efficient in assessing the environment of preschool centers.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.