The aim of this study was to investigate the work-related musculoskeletal disorders (WMSDs) among workers in wall plastering jobs within the construction industry.
OBJECTIVE: The unavailability of anthropometric data especially in developing countries has remained a limiting factor towards the design of learning facilities with sufficient ergonomic consideration. Attempts to use anthropometric data from developed countries have led to provision of school facilities unfit for the users. The purpose of this paper is to use factor analysis to investigate the suitability of the collected anthropometric data as a database for school design in Nigerian tertiary institutions.
PARTICIPANTS: Anthropometric data were collected from 288 male students in a Federal Polytechnic in North-West of Nigeria. Their age is between 18-25 years.
METHODS: Nine vertical anthropometric dimensions related to heights were collected using the conventional traditional equipment. Exploratory factor analysis was used to categorize the variables into a model consisting of two factors. Thereafter, confirmatory factor analysis was used to investigate the fit of the data to the proposed model.
RESULTS: A just identified model, made of two factors, each with three variables was developed. The variables within the model accounted for 81% of the total variation of the entire data. The model was found to demonstrate adequate validity and reliability. Various measuring indices were used to verify that the model fits the data properly. The final model reveals that stature height and eye height sitting were the most stable variables for designs that have to do with standing and sitting construct.
CONCLUSION: The study has shown the application of factor analysis in anthropometric data analysis. The study highlighted the relevance of these statistical tools to investigate variability among anthropometric data involving diverse population, which has not been widely used for analyzing previous anthropometric data. The collected data is therefore suitable for use while designing for Nigerian students.
KEYWORDS: Exploratory factor analysis; measurement model; school ergonomics
The complex and limited understanding of the interactions among multiple factors associated with back pain occurrence among schoolchildren might explain the current inconclusive and contradictory findings on the issue. The global increase in the prevalence of childhood overweight and obesity, which reportedly affects children's physical abilities, calls for concern among school/children ergonomists and other stakeholders.
The study analysed backpack-related back pain in school children by investigating the possibility of multiple interactions among causative factors, which may be responsible for the non-conclusive findings on the issue. Using data from 444 prepubescent schoolchildren, a mixed method design combining survey, observation and direct measurement strategies was implemented. Using a multivariate structural equation modelling approach, the study investigated interactions among anthropometry, posture, backpack volume, rating and back pain constructs, with each construct made of 2-4 indicators. Additionally, regression analysis was used to determine the feasibility of considering the two additional factors of age and body mass index along with the globally accepted recommendation of a load of 10-15% of body weight. Our model demonstrated an acceptable model fit and revealed direct and indirect effects of the factors. Obese children were recommended to carry a one-third lighter load than other children. The application of systematic/multiple strategies provided an explanation for some of the issues associated with school children's backpack-related back pain.
Prolonged standing can cause discomfort on the body of the workers and can lead to injury and occupational disease. One of the ergonomic intervention is through improving the work-rest scheduling. The purpose of this study are to identify the fatigue level from the perception of the worker and to investigate the impact of the work-rest scheduling to the standing workers for 12 h working time with a different gender. This study involved two methods which are self-assessment of the worker and direct measurement by using electromyography (EMG). For self-assessment, 80 workers have been interviewed using questionnaire in order to identify the fatigue level. For direct measurement, EMG was attached to the 15 selected workers at their respective leg and lower back to analyse the muscle efforts. In terms of perception, the results show the discomfort and fatigue level at the lower body region in the following order as foot ankle, lower back and leg. There is a significant difference between gender on discomfort pain for foot ankle and leg. The results show short frequent break by 10 min can reduce the fatigue at the leg and infrequent long break is preferable in order to reduce the fatigue at the lower back. In conclusion, it was found that prolonged standing affect the muscle fatigue and discomfort especially lower extremities such as foot ankle, lower back and leg. Besides that, different type of work rest scheduling and gender have significant result towards the muscle fatigue development.
This paper describes the development of the Workplace Ergonomic Risk Assessment (WERA) for investigating the physical risk factor associated with work-related musculoskeletal disorders (WMSDs). The initial development of WERA tool involved the following procedures: (1) first stage, development of WERA prototype from literature review, (2) second stage, evaluation of the psychometric properties including (a) validity trials and (b) reliability and usability trials. In the validity trials, the relationship of the individual WERA body part scores to the development of pain or discomfort is statistically significant for the wrist, shoulder and back regions. It shows that the WERA assessment provided a good indication of work-related musculoskeletal disorders which might be reported as pain, ache or discomfort in the relevant body regions. In the reliability trials, the results of inter-observer reliability shows that moderate agreement among the observers while from the feedback questionnaire survey about the usability of WERA tool, all participants including expert and management teams agreed that the prototype of WERA tool was easy and quick to use, applicable to workplace assessment for the wide range of job/task and valuable at work. It was confirmed that there was no need of training required to do WERA assessment. Therefore, the WERA assessment has been designed for easy and quick use, and for those who are trained to use it do not need previous skills in observation techniques although this would be an advantage. As WERA is a pen and paper technique that can be used without any special equipment, WERA assessment can be done in any space of workplaces without disruption to the task that have been observed.