1 CHAPTER 1 INTRODUCTION
1.1 Introduction
This chapter is divided into thirteen sections including this introduction. It explains the context and background of study in section 1.2, delay issues relating to elderly population in Malaysia in section 1.3, problem statement in section 1.4, research questions in section 1.5, research aim and objectives in section 1.6, theoretical framework in section 1.7, inquiry strategy in section 1.8, expected findings in section 1.9, scope and limitation of the study in section 1.10, significant of study in section 1.11, while section 1.12 covers the expected contributions and finally section 1.13 explains the organization of the thesis.
1.2 Context and Background of Study 1.2.1 Elderly Population
Based on the United Nations’ tariff set during the World Assembly of Aging, 1982 in Vienna, ‘elderly’ means a person aged 60 years and over. This tariff is applies to developing countries like Malaysia. Meanwhile the World Health Organization (WHO) which is a specialised UNs’ agency concerning with international public health classified elderly in developed countries as a person aged 65 and over. The age of 60 or 65, roughly equivalent to retirement ages in most developed countries is said to be the beginning of old age. In contrast, old age in many developing countries is seen to begin at the point when active contribution is no longer possible (Gorman, 1999).
2 Following to this tariff, this study will select persons aged 60 years and over. The physiology, psychology and pathology are three common changes in the ageing process.
These changes include some restricted movements of the legs, slowing down of directive functions, loss of alertness, loss of memory and reduced awareness. The normal effects of age are accomplished with varying frequency and extent by characteristic illness and infirmities (Grandjean, 1973). Regardless of the definition, it is bounded by the ageing process.
1.2.2 Elderly Demography in Malaysia
The number of elderly population in Malaysia keeps on increasing year by year due to their longer lifespan. Based on statistics from Department of Statistics Malaysia (2007) the Malaysian elderly population is at 6.82% out of its total population and will become aging society once its elderly population reaches 7%. In 1957 Malaysian lifespan is at the average of 56 years. According to Department of Statistics Malaysia (2013) the male life expectancy is 72.6 years and the female is 77.2 years made their average lifespan increase to 75 years. By the year 2020, the number or Malaysians aged 60 years and over is expected to reach 4.46 million people compared to 2.32 million now (Idris, 2014). This figures trigger alert that Malaysia should be prepared to face the challenge of the quality of life of the elderly in coming years. There are many reasons for how and why this has happened. Better medical facilities, shifting to a new nature of work, changes of lifestyle, better well-being and better food are some of the reasons. As women tend to live longer than men, the disproportion between males and females therefore also increase with aging. The sex ratio of men per 100 women will decrease from 90.1 in 1990 to 85.8 in 2020 (Mafauzy, 2000). The other feature on the demographic changes that is expected to occur in the aged population is in relation to urbanisation. The percentage of population in urban areas has increased from 24.5% in 1957 to 50.8% in 1990 (Mafauzy, 2000). This is due to out-migration of young rural
3 population to the urban areas in search for employment and education opportunities.
Later on remain staying in urban until their old age. As the absolute and relative number of elderly increases, research should be carried out to encounter the impending issues, such as increasing their independency and increasing quality of life as long as possible.
1.2.3 Ergonomic Related to the Aged Persons
Ergonomic study is an approach to investigate a task in accordance with the task performer. It is a branch of science that is concerned with the achievement of optimal relationship between workers and their work environment (Tayyari and Smith, 1997). In other words, ergonomic study is widely used to design task, evaluate task, improve present tasks design with consideration on lower energy expenditure, shorter time to complete a task, less stress, eliminating fatigue and relates to other biomechanical, physiological and psychological matters. The assessment could be based on the comfort, productivity, performance level, outputs and physical health of the performer.
Most ergonomic researchers are related to the ergonomic task design parameter and majority of them focused on physical ergonomics in the industrial or manufacturing sector (Stewart, 1995; Nichols, 1999; ANSI/HFES100, 2007). However, it is hard to find ergonomic researcher focuses on home instrumental activity of daily living’s (IADL) tasks specifically involve the fragile subject which is the ‘elderly’. This is the research gap that this study is going to investigate further.
Meal preparation is one of the main measurements of the elderly person’s level of independence. While in the ‘clinical and geriatrics’ disciplines, eating is number one in the measurement of ‘self-care’ (Turner-Stokes, et al. 1999). As people aged, their ability to perform tasks becomes less and finally they have to rely on others. The issues here are; how to increase the elderly person’s independency level and how to increase their quality of life so they could benefit from their longer lifespan.
4 To fill this gap one of the IADL task ‘frying’ was selected as the case study. Data acquisitions such as anthropometry, physiology, kitchen environment and kitchen triangle dimension were collected and analyzed. This includes video recording of the performed task by each subjects for postural analysis purpose. The analyzed result is tested to a controlled group to clarify which is/are answering the hypotheses.
1.3 Delay Issues Relating to Elderly Population in Malaysia
1.3.1 Critical Living Condition to Support Quality of Life among Elderly Population
The elderlies are less healthy than the young. Hence an increase in the population of the aged group is associated with an increase in the prevalence of ill health. The physical and social changes associated with aging are combined with the debilitating effects of multiple, acute and chronic diseases. Frailty in often compounded by problems such as urinary incontinence, instability, falls and acute confusional states. Before reaching this critical living condition or older old state, a delaying process to prolong elderly independency has to be considered in order to support their quality of life.
1.3.2 Task Performance and Work Environment
The task and the environment where a particular task is taken place are closely inter- related. The most significant human senses in performing task are seeing and feeling besides hearing, smelling, tasting and speaking. Human need light to see. Different task requires different brightness level. Human also require acceptable environmental temperature to be able to perform task effectively. There are also difference requirement between normal adult and the elderly person both in terms of brightness level and thermal comfort whilst performing task.
5 1.3.3 Identification of Elderly Common Tasks and Types of Task in Their
Homes
There are many activities performed by the elderly at home; either it is required or compulsory to be done for living. Home making, meal preparation and gardening are some of the examples.
1.3.3.1 Elderly and Activity of Daily Living Task
Activities of Daily Living (ADL) have been classified into two domains. They are Basic Activity of Daily Livings (BADLs) and Instrumental Activity of Daily Livings (IADLs).
1.3.3.2 Basic Activity of Daily Livings (BADLs)
Basic Activity of Daily Livings (BADLs) involves less complex, implicitly learned activities, such as bathing, dressing, and eating (Katz et al., 1963). It consists of self- care tasks including; bathing and showering, bowel and bladder management, dressing, eating, feeding, functional mobility, personal device care, personal hygiene and grooming, sexual activity, and toilet hygiene.
1.3.3.3 Instrumental Activity of Daily Living (IADL)
The Instrumental Activity of Daily Livings (IADLs) on the other hand is not necessarily for fundamental functioning. It involves more cognitively demanding tasks, such as managing money or medication (Lawton & Brody, 1999), house-keeping, meal preparation and cleanup, shopping, using the telephone, using other technology, and transportation within the community. The American Occupational Therapy Association (AOTA) in its IADLs evaluation involved other criteria such as; care of others, care of pets, child rearing, religious observances, and safety procedures and emergency responses.
6 1.3.4 Identification of Critical Living Condition to Support Quality Living
among Elderly
There are two types of elderly living categories. The elderly residing at the Nursing Home are categorized as dependent living. Many of them do not actively perform IADL compared to those staying at their own houses. This is due to physical and cognitive abilities of the elderly, or safety regulations of the dwelling-house. They probably perform certain Basic Activity of Daily Living (BADL) tasks since their meals are served, the garments are cleaned and dried and the beds are tidied-up by care givers working at those premises. The cleanliness of the premises is also taken care of by the management. Other activities are planned for them and monitored by the management.
Elderly in this category are at the stage of critical living condition as they become weaker day by day.
The second category is independent living. Those elderly in this category perform BADL and IADL tasks themselves. Most of them resided in their own homes and living in a community. They perform many tasks and activities inside and outside of their houses. This includes socializing, visiting neighbours and relatives, shopping for groceries, attending celebrations such as weddings, taking part in religious functions and ceremonies and so forth. The elderly from this category is the focus of this study.
1.3.5 Increasing Elderly Independency and Improving Their Quality of Living
Productivity and performance are synonyms and inter-related but there are multiple factors that could influence the measurement of these two terms. There have been many suggestions to improve task design, equipment, working environment and the method of doing things in the simplest, safest and fastest way. In particular; reference to industrial
7 workers as the human component is recognized as central to the productivity and performance in the manufacturing industries (Rouse et al., 1991). But it is hard to find research on the elderly with regards to performing home daily tasks. The decline of human capabilities and performance is significant with age. The older the person, the weaker and slower they are in physical performance. Therefore, it is crucial to investigate the task performing and working environment of the elderly to avoid strain and fatigue while performing daily activities.
According to Kroemer et al. (2000), based on ergonomics, fundamentally, all man-made tools, devices, equipment, machines and the work place environment should be advanced, safe and support well-being. These factors relate to productivity, safety, convenience and quality of life. This comfort perception applies to all adults but, for the elderly it is even more crucial since they are presently experiencing the ageing process.
This thesis explores the ergonomics approach to propose solutions to the issues using a selected case study. Five major variables were investigated, analysed and tested. There are two types of proposed solutions. Firstly, a recommendation to improve the workplace environment by providing criteria as well as suggesting a suitable kitchen layout design and triangle distance. Secondly, an adjustable stove height has been fabricated and ergonomically tested to meet user’s preferable stove table-top-height accordingly to their anthropometric dimensions. Ergonomically and user-friendly stove table-top design had to be established to ensure the elderly could perform the frying task conveniently.
8 1.4 Problem Statement
There are two major issues in this study. They are ‘increase independency’ and
‘increase quality of life’ of Malaysian elderly population. These issues are basic facts of present elderly situation which need serious attention. To further investigate these issues, a problem statement was set to address. The problem statement is: Malaysia is expected to become an aged society by the year 2020. Hence there is a need to prolong the independency of its senior citizens by improving their residential environment.
The future improvement through an ergonomic approach is hoped to enable elderly to perform daily activities or tasks on their own until such time they really need assistance from caregivers or family members. The elderly person’s quality of life and independent living should be as long as possible for many reasons. Some of the reasons are;
Malaysia is projected to be an aging society by 2020 and already the elderly population is tremendously increased. The Malaysian elderly population (aged 65 and over) at present is 1,443,300. This is 5.1% of its total number of 28.3 million. Out of that there is 13.6% yearly incremental number of elderly added to the present figures (Department of Statistics, Kuala Lumpur, 2011).
Elderly are exposed to a breakdown of functional impairments especially in performing activities of daily livings (ADLs). They are in the aging stage where the process involves complex body changes and changing interactions with environmental systems (Lawton et al., 1999). Surveys have shown that the older populations (65+) have great difficulty in performing one or more common self-care activities such as preparing a meal in the kitchen (Dawson et al., 1987, AARP, 2000). Human hearing sensitivity and auditory processing declines gradually and progressively with aging and so the cognitive decline (Gordon-Salant, 2005). Visual and hearing impairments decrease
9 independence in performing the activities of daily living, getting from place to place, or communicating with others. Older person are disproportionately affected by sensory impairments as well (Desai, et al., 2001).
It the same time, there are a small number of nursing homes and caregivers in Malaysia compared to the increasing numbers of elderly growth. Furthermore the Malaysian Government will stop building any ‘elderly homes’ in its 11th Malaysia Plan as announced by the Minister of Woman, Family and Community Development (Sinar Harian, May 5, 2014). This is to ensure the children take the responsibility to look after their old parent.
Table 1.0 Eagle Research Design Table Construct Research
Question Construct Description
Sub-Research Question / Research Objective
Strategy of Inquiry
Outputs Knowledge
Contribution
WHO Elderly
Population
Sub RQ1 What is the present state of living among elderly population in Malaysia?
RO1
To understand the present state of living among elderly
population in Malaysia.
Literature Research
•Documentation of demography information about elderly population in Malaysia
•Documentation of issues & problems relating to elderly population.
•Identification of critical living condition to support quality living among elderly population.
•Theory towards increasing elderly independency and improving their quality of life.
WHAT Ergonomics Sub RQ2 Which ergonomic factors are affecting task performance of elderly population in their homes?
RO2
To identify the ergonomic
Literature Research
•Identification of their common and types of tasks for elderlies in their homes.
•Categorization of task for ergonomics measurements.
•Identification of ergonomic variable affecting task
•Theory to improve elderly comfort perception by ergonomics means. (TP1)
10
factors that is affecting task performance of elderly population in their homes.
performance among elderly.
Table 1.0 Eagle Research Design Table (continue) Construct RQ
Construct Description
Sub RQ/RO Strategy of Inquiry
Outputs Knowledge
Contribution HOW 1 Enhance
comfort perception
Sub RQ3 What are the significant factors for enhancing comfort perception among elderly person when they perform their tasks?
RO3
To identify the significant factors for enhancing comfort perception among elderly person when they perform their tasks.
Literature Research
•Categorisation of significant factors enhancing comfort perception among elderly while performing tasks.
•Identification of comfort perception variables that could significantly support task performance by elderly.
•Theory to enhance comfort perception during task performance for the elderly.
(TP2)
HOW 2 Improve residential built environment
Sub RQ4 What are the recommendations for ergonomic interventions that could enhance comfort perception for improving residential built environment for the elderly population?
RO4
To recommend ergonomic interventions that could enhance comfort perception for improving residential built environment for the elderly population.
Case study •Recommendation of design
guideline and task performance for elderly residential.
•Proof of concept prototype of adjustable working table.
•Theory for applying ergonomic intervention that could enhance comfort perception for improving residential built environment for the elderly population.
•Design Model for using anthropometric dimensions for elderly residential design.
•Prototype of adjustable working table that is fabricated based on elderly anthropometric dimensions.
(TP3) TP – Theory Proposition
11 A complete Eagle Research Design Table outlays the sub-research questions, research objectives, strategies of inquiry, expected output and knowledge contribution. This is after identification of the research question construct description (Ibrahim, 2011). This Eagle Research Design Table (Table 1.0) will be the reference for the next sections of 1.5, 1.6, 1.7, 1.8, 1.9 and section 1.12.
1.5 Research Questions
There is one main research question and four sub-research questions in this study. The main research question is; what is the role of ergonomics in enhancing comfort perception for improving residential built environment for the Malaysian elderly population? The sub-research questions are:
1. What is the present state of living among elderly population in Malaysia?
2. Which ergonomic factors are affecting task performance of elderly population in their homes?
3. What are the significant factors for enhancing comfort perception among elderly person when they perform their tasks?
4. What are the recommendations for ergonomic interventions that could enhance comfort perception for improving residential built environment for the elderly population?
1.6 Research Aim and Objectives
There are four objectives in this study. They are:
1. To understand the present state of living among elderly population in Malaysia.
12 2. To identify significant ergonomic factors that affecting task performance of
elderly population in their homes.
3. To determine significant anthropometric dimensions that could enhance comfort perception among elderly person when performing their task in the kitchen.
4. To develop anthropometric workstation design model that could enhance comfort perception for elderly in the kitchen.
1.7 Theoretical Framework
The ‘activity theory’ or implicit theory of aging, normal theory of aging, and lay theory of aging (Loue and Sajatovic, 2007), proposed that successful aging occurs when older adults stay active and maintain their social interactions. It takes the view that the ageing process is delayed and the quality of life is enhanced when old people remain socially active (Schulz, 2006). The activity theory rose in opposing to the ‘disengagement theory’ (Bengtson and Putney, 2009). The activity theory and disengagement theory were the two major theories that outlined successful aging in the early 1960s (Schulz, 2006). The theory was developed by Robert J. Havighurst in 1961 (Loue and Sajatovic, 2007). The activity theory is one of three major psychosocial theories which describe how people develop in old age (Ebersole, 2005). The other two theories are the disengagement theory, with which the activity comes to odds, and the ‘continuity theory’ which modifies and elaborates upon the activity theory. Activity theory reflects the functionalist perspective that the equilibrium that an individual develops in middle age should be maintained in later years (Schulz, 2006).
The previously observed phenomenon on Malaysian elderly living is very significant to this ‘activity theory’. Besides its’ incremental number of elderly population and small
13 number of nursing homes the theoretical framework in this study is geared to increase independency and increase quality of life guided by this theory. These impending issues are also stated in the Problem Statement in section 1.4. From this ‘activity theory’, three constructs are selected for the research methods namely; Comfort Perception, Postural Measurement, and Physiological Limitation. Meanwhile, three hypotheses are developed and combined as a theory proposition for this study. The hypotheses are:
H₁ Comfort Perception improve (when) Postural Measurement is within range of acceptance during task performance
H₂ Comfort Perception improve (when) Physiological Limitation is within range of acceptance during task performance
H₃ Comfort Perception improve (when) Postural Measurement and Physiological Limitation matched with acceptable range during task performance
Detail of constructs and hypotheses will be discussed in Chapter 3.
1.8 Inquiry Strategy
1.8.1 Literature research inquiry strategy
Literature research or literature review is selected as inquiry strategy to convey knowledge and ideas that have been established on this topic as well as to know their strengths and weaknesses. It is a systematic, explicit, and reproducible method for identifying, evaluating, and synthesizing the existing body of completed and recorded work produced by researchers, scholars, and practitioners (Fink, 2005). As an assessment of a body of research that addresses some research questions it gives a theoretical base for the research. By reviewing the work of others in the same area (Caplan, 2010) one could reveal ‘state of the art’ on the subject he or she is working on and this is where research gaps normally identify.
14 This literature research method is used to further investigate ‘elderly population’ for sub-research question No.1 and research objective No.1; ‘ergonomics’ for sub-research question No.2 and research objective No.2; and ‘enhance comfort perception’ for sub- research question No.3 and research objective No.3.
1.8.2 Case Study inquiry strategy
Case Study inquiry strategy is a descriptive, exploratory or explanatory analysis of a person, group or event (Jon and Greene, 2003, Yin, 2009). It is believed case-study method was first introduced by Frederic Le Pay in 1829 (Healy, 1947) as a handmaiden to statistics in his study. According to Lamnek (2005) the case study is a research approach, situated between concrete data taking techniques and methodological paradigms. When selecting a subject for a case study, researchers will therefor use information-oriented sampling, as oppose to random sampling. It is popular in testing hypotheses (Stake, 1995).
In this study the ‘case study’ is refer to the selected task that is to be performed by the elderly and the activity is video recorded for motion analysis. Some other data regarding the space where they perform the task are also collected. The results from the analysis are tested to the same task in a controlled condition. This case study is used to answer research question No.4 on how to improve residential built environment. It is also to answer sub-research question No. 4 and research objective No. 4.
1.9 Expected Findings
From the literature research, 3 sub-research questions (No.1, 2 and 3) and 3 research objectives (No.1, 2 and 3) are expected to cover. While the case study will only cover sub-research question No.4 and research objective No.4.
15 1.9.1 Sub-research question No.1 and research objective No.1
The first output for sub-research question No.1 is documentation of demography information about elderly population in Malaysia. The second output for sub-research question No.1 is documentation of issues and problems relating to elderly population.
The output for research objective No.1 is identification of critical living condition to support quality living among elderly population.
1.9.2 Sub-research question No.2 and research objective No.2
The first output for sub-research question No.2 is identification of elderly common tasks and type of tasks in their homes. The second output for sub-research question No.2 is categorization of task for ergonomics measurements. While the output for research objective No.2 is identification of ergonomic variable affecting task performance among Malaysian elderly.
1.9.3 Sub-research question No.3 and research objective No.3
The output for sub-research question No.3 is categorization of significant factors enhancing comfort perception among elderly while performing tasks. The output for research objective No.3 is identification of comfort perception variables that could significantly support task performance by elderly.
1.9.4 Sub-research question No.4 and research objective No.4
The output for sub-research question No.4 is recommendation of design guideline and task performance for elderly residential. The output for research objective No.4 is the proof of concept prototype of adjustable working table.
16 1.10 Scope and Limitation
Ergonomic study is a multi-disciplinary in nature and covers many fields such as psychology, physiology, biomechanics, sociology, anthropology, anthropometry, industrial engineering, industrial design and philosophy. Therefore, it is necessary to limit the scope of this study to accomplish the thesis objectives. This study gathered some information on Malaysian elderly in terms of their nature of living and issues on performing common daily home tasks. It focuses to their kitchen setting where cooking took place as meal preparation is the most important measures to classify their independence level. Frying case study is selected to gauge the postural and physiological factors of the elderly task performance. Other ergonomic factors are anthropometry, kitchen environment and kitchen triangle distance.
This study did not, however, investigate elderly from ‘dependence living’ category.
Number of subject in this study is 30 people since case study approach is not rely on random sampling which requires huge numbers for statistical analysis to represent the actual population. In the first session, 220 elderly participated for demographic data collection. This requires huge number of participant since it relies heavily on statistical analysis. In the second session which is collecting anthropometrics measurement data only 55 elderly participated. The data is to establish stove width and length dimensions.
In the final session there are only 30 elderly houses had been visited and data from them were collected. The reduction number of participants is greatly due to many reasons.
Some of them are; health status, committed to other family agenda, time constraint, difficulty in arrangement of data collection at their kitchens, and their availability to participate within the given timeframe. Some of them had passed-away within the data collection period. This does not affect the results as there are studies using only three or even less elderly subjects in their PhD theses especially on ‘case study’ basis.
17 1.11 Significance of the Study
This study focuses on the elderly performing Instrumental Activity of Daily Living’s (IADL) task. There has been little research focusing on Instrumental Activity of Daily Living’s (IADL) task performing. In Malaysian context it is a rare case where researchers study elderly IADL task performing. There are so many unanswered questions to investigate. For example, how do they perform the task; how long they spend time doing all these tasks; are they facing any physical fatigue related to the task;
what is wrong with the tools or equipment they use; are they satisfy with the working environment; are they willing to participate in research; how to approach them in the research and so forth.
This section provides description on the various significances of the study. To the elderly, output from this proposed ergonomic study will increase their independency and improve their quality of life. Task performance could be much easier and painless.
To the ergonomists, the proposed study will provide deeper understanding about issues on elderly task performing and increase their awareness to study other home tasks. To the future researchers, the research process proposed in this study could be used as a guide to investigate other IADLs tasks with concerning the elderly. Therefore, ergonomic research on the Instrumental Activity of Daily Livings (IADLs) task for elderly should be prioritized and conducted broadly and frequently.
1.12 Expected Contributions
There are four expected knowledge contributions based on 4 outputs from all research questions from this study. They are;
18 1.12.1 Output from construct WHO: elderly population
The expected knowledge contribution for this section is theory towards increasing elderly independency and improving their quality of life.
1.12.2 Output from construct WHAT: ergonomics
The second expected knowledge contribution is theory to improve elderly comfort perception by ergonomic means.
1.12.3 Output from construct HOW 1: enhance comfort perception
The third expected knowledge contribution is theory to enhance comfort perception during task performance for the elderly.
1.12.4 Output from construct HOW 2: improve residential built environment
The last expected knowledge contribution consists of 3 elements. First, a theory for applying ergonomic intervention that could enhance comfort perception for improving residential built environment for the elderly population. Second, design guidelines for using ergonomic intervention for elderly residential design. Finally, the prototype of adjustable working table that is fabricated based on elderly anthropometric dimensions.
1.13 Organization of the Thesis
There are seven chapters in this thesis.
• Chapter 1 presents an overview of the elderly population, its demography and ergonomic related to the aged persons. It touches elderly activity of daily living (ADL) and their critical living condition supporting the elderly quality of life. It also touches task performance and work environment, identification of elderly common tasks, identification of critical living condition to support quality living
19 among elderly and increasing elderly independency and improving their quality of life. Chapter 1 also states the problem statement, research questions, aim and objectives of the research, theoretical framework, inquiry strategy, expected findings, scope and limitation, significance of the study and expected contribution of the study. This chapter ends with a summary.
• Chapter 2 is reviews the ‘ergonomics’, enhancing comfort perception, task performance, and improving residential built environment. Reviewing
‘ergonomics’ includes the introduction to ergonomics, its definitions, nature of ergonomic research, introduction to anthropometry, postural and physiology, significant factors, benefit of factors, current study, categorising task for ergonomic measurements and ergonomic variables affecting task performance among elderly. Reviewing ‘enhancing comfort perception’ includes definition, general introduction to comfort perception, related theories, gaps, factors enhancing comfort perception and factors that could support task performance by elderly. In reviewing ‘elderly task performance’ this includes definition of task performance, and task performance in the ergonomics point of view. Here, the expected outcomes are stated. In ‘improving residential built environment’
on another hand, includes current design guidelines for elderly residential, ergonomic intervention that could enhance comfort perception for improving elderly residents, improving task performance by ergonomic means, recommending ergonomic design model using anthropometric dimensions, and prototype of adjustable working table. This chapter then ends up with a summary.
• Chapter 3 describes the methodology used in this study. It shows the research framework, the selection of elderly from their demography, the investigated
20 ergonomic factors, questionnaire design and method of data analysis. This chapter ends with a summary.
• Chapter 4 presents the results from the analysed collected data. This includes results from the preliminary survey. This chapter ends with a summary.
• Chapter 5 presents the fabrication of anthropometric adjustable stove height prototype and testing. This chapter explains the data collection, result and analysis from the prototype testing. This chapter ends with a summary.
• Chapter 6 present the discussions and findings from the results of this study.
This chapter ends with a summary.
• Chapter 7 is the conclusion of this study which states;
i) Key findings and output of the study ii) Limitations of the study,
iii) Major contributions, and
iv) Recommendation for future work This chapter ends with a summary.
21 CHAPTER 2 LITERATURE REVIEW
2.1 Introduction
This chapter presents a review of the literature on ergonomics, elderly comfort perception, task performance, and improving residential built environment. It elaborates the role of ergonomics by identifying the ergonomic factors that is affecting task performance of elderly population in their homes. It explains the elderly common tasks and type of tasks as well as categorization of task for ergonomic measurements.
This chapter is divided into six sections including the introduction in the first section. It explains the ergonomics in section 2.2, enhancing comfort perception in section 2.3, task performance in section 2.4, improving residential built environment in section 2.5 and end up with a summary in section 2.6.
2.2 Ergonomics
‘Ergonomics’ or ‘human factors’ is the scientific discipline concerned with the understanding of interactions among humans and other elements of a system, and the profession that applies theory, principles, data and methods to design in order to optimise human well-being and overall system performance (IEA, 2000, and Marras, 2013). Based on this statement, ergonomics is chosen as part of the research questions to answer the problem statements in this study. Here are some reviews about ergonomics:
2.2.1 Definition of Ergonomics
Ergonomics is the science of work. It derives from two Greek words: ‘ergon’ meaning work and ‘nomoi’ meaning natural laws. Combined they create a word that means the
22 science of work and a person’s relationship to that work (Adams, 2014). According to Online Etymology Dictionary (Harper, 2010) ergonomics is a scientific study of the efficiency of people in the workplace. In other words, ergonomics is the science of designing the job to fit the worker, rather than physically forcing the worker’s body to fit the job. Ergonomics can also be defined simply as the study of work (OSHA, 2000).
It is also known as comfort design, functional design, and user-friendly systems. The British Dictionary defines ergonomics as the study of the relationship between workers and their environment especially the equipment they use. The Stedman’s Medical Dictionary defines ergonomics meaning the applied science of equipment design, as for the workplace, intended to maximise productivity by reducing operator fatigue and discomfort.
Adapting tasks, work stations, tools, workspace and equipment to fit the worker or user can help reduce physical stress on their body and eliminate many potentially serious, disabling work-related musculoskeletal disorders (WRMSDs). Ergonomists have a role to evaluate tasks, products, environments and systems compatible with needs, ability and user’s limitations while industrial designers and engineers design these necessities accordingly to user’s requirements.
2.2.2 General Introduction to Ergonomics
Ergonomics draws on a number of scientific discipline including; anthropometry, biomechanics, physiology, psychology, kinesiology and industrial hygiene. These scientific disciplines can be classified into three basic ergonomic domains namely;
cognitive, physical and organizational ergonomics. This study is focused on physical ergonomics as it touches the human anatomical, anthropometric and physiological characteristics which relates to physical activity of performing a task.
23 2.3 Enhancing Comfort Perception
The second point of departure in this study is that enhance elderly comfort perception could improve their task performance. This section will elaborate literature on enhancing comfort perception.
2.3.1 Definition of Comfort Perception
Comfort is a state of ease and satisfaction of bodily wants, with freedom from pain and anxiety. Perception is the organization, identification, and interpretation of sensory information through the medium of bodily organs or by the mind of what is presented to someone. It is an act of perceiving the environmental condition psychologically and physically. Therefore comfort perception is someone’s interpreted comfort preference towards the task of what he/she is doing. Different working posture for example will require different comfort perception to certain people. In this study, comfort perception means the elderly preferable or acceptable comfort level during performing frying task.
2.3.2 General Introduction to Comfort Perception
Every task has its own range of comfort level based on who is the performer of that particular task. Body anthropometrics, age cohort and gender differences are example of variables that could contribute to person comfort perception on certain task performing.
The REBA (Rapid Entire Body Assessment) for example is one of the methods of evaluating postural comfort level towards the task. A specific set of questionnaires could also very useful to assess someone comfort perception on the task he/she is doing.
24 2.3.3 Theories on Comfort Perception
It is hard to find specific theory on comfort perception for elderly performing daily activities. However, it is undeniable that people perceive comfort in task performing especially in the industrial or manufacturing sectors. Mostly it relates to materials handling, work postures, productivity and safety and health of the workers.
‘Productivity theory’ could be used for workers but for elderly doing ADL task, theory to enhance comfort perception during task performance could be suitable in this context.
Therefore it is important to evaluating their comfort perception against task they performed.
2.3.4 Gap Analysis of Comfort Perception
Since there is no specific theory on comfort perception, therefore no gap analysis on comfort perception. Many researches focused on workers and their tasks that benefit production workers and manufacturers. The non-existed comfort perception itself shows the gap between task performance and comfort perception both on adult workers as well as the elderly population.
2.3.5 Factors Enhancing Comfort Perception among Elderly
There are many ergonomic factors that could enhance elderly comfort perception upon performing any daily tasks. Some of them could be measured quantitatively while the others require qualitative approach which is relies on feedbacks from the users. The ergonomic factors are anthropometrics, physiology, working posture, kitchen environment and kitchen triangle distance.
25 2.3.6 Comfort Perception Factors that could Support Task Performance
by Elderly
In this study which frying is the selected task, the comfort perception factors that could support task performing by elderly are their preferable stove height. Their stoves height preferences which make them physically comfortable have a great significant with their working posture and body dimensions. Besides the anthropometry and working posture, physiological and kitchen environmental factors could also support elderly task performance.
2.4 Task Performance
In relation with Section 2.3, this section remain using the second point of departure in this study which was ‘enhance elderly comfort perception could improve their task performance’. This section will elaborate literature on enhancing task performance.
2.4.1 Definition of Task and Task Performance
Task means any piece of work often to be finished by a person within a certain time. In the contact of this study it refers to activities required to be done by the elderly for their daily living. On the other hand, performance means the execution or accomplishment of work. It is the act of performing a work or task. Therefore task performance can be defined as execution of a work within a certain time.
2.4.2 Selection of IADL task
One of the most important IADL tasks is meal preparation. It involves issues on the nature of the task and the instrument used to perform the task. Meal preparation is also identified as the main measurement of elderly level of independency (Turner-Stokes, et.
al., 1999). From a preliminary survey it was found that this crucial task is so tiring
26 because there are ‘pre and post activities’ involved in the whole process. More than 20% of the subjects require assistance due to their limitations. The selected method within meal preparation is frying. Since it is the most popular method among Malaysian elderly population compared to roasting, steaming or boiling the findings from this case study hopefully could benefit majority of elderly.
2.4.3 Factors Affecting Frying among the Elderly
Beside elderly health condition and physical capability, there are many factors that could be considered in evaluating frying task. It could be the task-design itself, the equipment and furniture used or the kitchen setting. To further investigate the affecting frying factors among elderly, five factors are selected. They are anthropometry, working posture, physiology, kitchen environmental and kitchen triangle distance factors. The findings will show the affecting factors of elderly frying task.
2.4.4 Physiological Capabilities
A physiological study is a way to translate the capabilities and limitations of the body reacting to task performance. The more strenuous the activity, the more oxygen consumption will be needed by the body.
As a person gets older their physical capabilities are decreased significantly. Performing several daily tasks requires certain physical ability. Assuring that job demands do not exceed worker’s capabilities is the responsibility and goal of those in the field of ergonomics. If a person’s capabilities are known, they may be used as a criterion for job design (Garg et al., 1978). Energy expenditure for example could vary between different tasks. Therefore it is crucial to measure the physiological limitation of the elderly to avoid strain and fatigue in performing daily activities.
27 2.4.5 User’s Anthropometry towards Task and Space Setting
Physical dimensions have a relation with human movement. A smaller person for example has a shorter footstep distance compared to a taller person’s footstep.
Therefore, anthropometric dimensions are significant when designing a task or work place setting. Parameters such as width, length and height of a working table may affect the performance or comfort in performing a task. Human anthropometry is also very useful as a guideline in designing products, equipment, furniture, transport or even buildings.
Anthropometry is the study of human body measurement for use in anthropological classification and comparison (Answer.com, 2010). According to Wilcox (2002), anthropometry is the study of the shape and size of a human body. Roebuck (1995) explains anthropometry is the science of measurement and the art of application that establishes the physical geometry, mass properties, and strength capabilities of the human body.
Another application of anthropometry is setting parameters for a work envelope.
According to National Aeronautics and Space Administration of America (NASA), a work envelope is a region in three-dimensional space in which a person can comfortably work. A work envelope can be explained as a space which can cater for part or the whole human body movement when performing certain tasks. In this study the standing posture and work envelope of the elderly is derived from their anthropometric measurements.
28 2.4.6 Working Posture
Working in a kitchen could be an issue for some elderly especially when preparing a meal. This is due to shrunk cartilage throughout their spine which reduces their standing strength ability and endurance. The aged person’s posture has a slumped character that could limit their movements (Tilley, 2002). According to Opila et al. (1988) the line of gravity is forward of the spine (Lumber No.4 and No.5), meanings that the body has a forward bending moment, counter balanced by ligament forces and back muscle forces.
If the body centre of gravity is moved forward, it causes a variety of biomechanical stresses while standing or walking (Lee et al., 2001). Another factor is that 50%
reduction of leg strength (Tilley, 2002) decreasing the elderly standing endurance which may require them to use supportive instruments such as canes, tripod aids, walkers or even a chair when cooking.
Ecologically, the elderly are exposed to a breakdown of functional impairments. These include changes in anthropometry, musculoskeletal attributes, respiration and circulation, nervous functions, capacity for physical work, brain and memory, visual functions, hearing, taste and smell, sensitivity and also sensory and psychomotor performance. These factors have a negative impact towards the performance of instrumental activities of daily living (IADL) task or even the basic activities of daily living (BADL) task. In household settings, the body action to complete a task such as opening a can of red beans is considered far more complex than cellular or molecular mechanisms of aging due to complex body and environmental systems involved.
Surveys have shown that older populations (65+) have great difficulty in performing one or more common self-care activities such as eating, using the toilet, dress, bathing, or preparing meals in the kitchen (Dawson et al., 1987; AARP, 2000; Taha and Ruhaizin, 2008).
29 Cooking is normally performed in a standing posture. This is because ordinary meal preparation requires high physical mobility between a work-triangle. The performers in this case the elderly, will have to stand and use both hands to perform the task whether they are right or left handed. The dominant hand will normally perform the main task and be supported by the other hand. The right handed users for example, will hold the ladle with the right hand while the left hand is holding and stabilizing the frying pan against the forces of stirring.
Besides physical frailty, the other factor affecting cooking is the height of the stove and work-top. For example, the incorrect height of table-top could contribute to shoulder fatigue, neck pain, back pain and elbow pain. The actual task of frying normally requires hand rising due to the additional stove height and the height of the frying pan.
Furthermore, the ladle set used for mixing the cuisine could also increase the height of hand raising and making the situation worst. Providing a stepping stool for a shorter person may overcome the problem, but this short-term solution could also contribute to an accident in the kitchen.
Fig. 2.1 The table-top is higher than the elderly’s waist height
30 Fig. 2.2 The stove is too high compared to her anthropometry
Fig 2.3 Low table-top height
The Figure 2.1, Figure 2.2 and Figure 2.3 show different posture of elderly person’s performing frying tasks at their home settings. These figures show different ratio between elderly waist height and the table-top height. The is due to wrong table-top height setting that could cause pain, discomfort or even fatigue to certain body parts of the user. Figure 2.1 shows an elderly still having difficulty while frying although she had placed 2 pieces of brick to increase comfort. Figure 2.2 shows an elderly having difficulty performing frying task. Her elbow is higher than the shoulder.
Anthropometrically she is too short compared to the stove height. This contributes to shoulder pain. Figure 2.3 shows an elderly performing frying task in her kitchen with low table-top height. Having a low table-top height increases flexion and this could cause fatigue to the neck. Figure 2.4 taken from FAA William J Hughes Technical
31 Center (Wagner et al., 1996) illustrates the 10 degrees extension and 10 degrees of neck flexion limit. Both neck tilts should not exceed this range to avoid discomfort.
Fig. 2.4 Neck Extension (A) and Flexion (B)
Some of the examples above could contribute to musculoskeletal disorder primarily on the shoulder, neck and elbow. Konz and Johnson, (2004) stated that musculoskeletal disorder is also known as occupational cervicobrachial disorder (OCD) or upper limb disorder (ULD). Once an elderly having this disorder, the chances of getting back to normal are very slim or negligible. He or she definitely will have to depend on others for the rest of their life. Therefore, it is worth it to investigate elderly comfort perception whilst frying regards their anthropometrics measurement, working envelopes and kitchen stove height.
The most common height for a kitchen counter top is 91.5 cm (3 feet). Ready-made base cabinets are designed for this finished height. The height of 91.5 cm is typically the optimal and most ergonomic height for a kitchen counter. It may not be the best for a specific task, but it is the best overall compromise for the majority of tasks done in the kitchen. For most people, a kitchen counter top height of 91.5 cm provides a comfortable work station (About.com, 2010). Extremely short or tall people, or those with special needs, may want to modify that height to better suit their needs.
32 Referring to the National Kitchen & Bath Association (NKBA, 2013), the minimum height of first level, which is 71cm (28 inches), shows that a product complies with the requirements of the elderly. On the other hand, referring to NKBA maximum height of second level, which is 114cm (45 inches), shows the product is too high for Malaysian elderly. According to Peterson (1998) and Tilley (2002), kitchen cabinets are 91.5 cm standard height and 61cm (24 inches) deep. NKBA had proposed two levels of work- counter heights. One is 71 cm (28 inches) to 91.5 cm above the finished floor and the other one is 91.5 cm to 114cm, (Krengel, 1997).
One of the popular methods of assessing working posture assessment methods is Rapid Entire Body Assessment (REBA). It was designed in UK to provide a quick and easy observational postural analysis tool for whole body activities in health-care and other service industries (Hignett and McAtamney 2000, Hignett 2006, McAtamney 2005).
REBA has two groups to assess. Group A includes trunk and neck, and legs and Group B includes upper arms, lower arms, and wrist. These groups are combined and transformed to a general posture score. At the end scores are summed up to have one score for each observation. These scores are compared to tables stating risk on five levels and actions needed from ‘none to necessary now’.
2.4.7 Working Space Environmental Factors
Kitchen is the hub of a house. Many activities are carried out in this space such as sweeping, mopping, meal preparing, cooking, eating, and crockery cleaning and so on.
As the most important room in a house, its environment should be conducive when performing daily kitchen activities. An ergonomic approach (Helander, 1995; Pinto et al., 1996) and gerontechnology (Bouma and Graafmans, 1992) would improve the
33 relationship between the aging user and the environment. The environmental factors in this study are the temperature, humidity and brightness level.
Conducive environment is crucial to anyone when performing daily living activities especially the elderly. Kitchens should have a good thermal comfort. It should provide an environment that imposes as small as possible on the body’s own thermoregulatory system (Corlett and Clark, 1995). The ability to thermoregulate typically decreases with age. This is strongly related to decreases in physical fitness and increases in the incidence of disabilities with aging. The reduced thermoregulatory capacity leads to increased mortality and morbidity. Heat stroke, hypothermia, increased number of falls, and in-home drowning are some of the problems that are identified to be associated with this reduced thermoregulatory capacity (Havenith, 2001). Poor thermal environment causes; reduced physical performance, irritability and distraction from the task, and reduced mental performance, discomfort from sweating or shivering, increased load on the heart and finally death (Corlett and Clark, 1995). Temperature is one of the principal parameters of thermodynamics. In physics, temperature is a physical property of a system that underlies the common notions of hot and cold.
There have been numerous studies on the effects of surrounding environment on human performance. The considerations of the effects of thermal environment are psychological parameters which lead to individual differences (Parsons, 2000). The questionnaire on thermal comfort adopts ASHRAE (1996) definitions as ‘the condition of mind which expresses satisfaction with the thermal environment’. Abdulshukor and Young (1993) found that the preferred climate chamber for Malays is 28.0 ºC while for the Chinese it is 28.7 ºC. According to Sabarinah et al., (2007), the comfort band of home temperature in Kuala Lumpur is between 23.6ºC and 28.6ºC.
34 Humidity and temperature are inter-related. Humidity is critical mostly in a hot environment. It will restrict heat loss by evaporation (Corlett and Clark, 1995). Relative humidity is defined as the ratio of the partial pressure of water vapour in a parcel of air to the saturated vapour pressure of water vapour at a given temperature. Relative humidity is expressed as a percentage (%RH). Temperature and humidity are two important factors in maintaining optimal comfort levels and good indoor air quality of a working space.
Lighting is also another environmental factor and it is an important consideration in improving the visibility in the workplace environment (Reiling and Chernos, 2007).
Insufficient light source in a working area generally can affect task performance. Poor visual environment can induce; visual discomfort and headaches, error and inability to see detail, confusion, illusions and disorientation and epilepsy (Corlett and Clark, 1995).
According to Adams (2014), the cooking and food preparing tasks require 300 to 750 lux of brightness level. The recommended kitchen light level by Bliss (2006) is 30-50fc (foot candle) brightness which is approximately between 323 lux to 538 lux. Therefore, it is important to investigate the elderly person’s kitchen thermal comfort and brightness level. Results from the actual measuring will identify the status of elderly kitchen environment and the right kitchen environment can then be obtained upon the validation process.
2.4.8 Kitchen Design and Triangle Distance
Kitchen size is important to a space user especially in terms of its ergonomics design consideration. Therefore it should be part of kitchen planning. Planning, it is often said, is for people, and with people a start must be made (Fraser, 1972). This is where the
35 sizes, shapes and spaces are calculated. To ensure the elderly remain independent in their own home setting, designers should consider the ergonomic aspects of the kitchen.
A well-designed kitchen should basically consider the layout, arrangement of cooking utensils, furniture and the user’s movement flow, besides physical and physiological aspects.
As far as the frying task is concerned, there is another crucial criterion in designing kitchen space. The most important rule here is the work triangle or kitchen triangle which involves distances between sink, fridge and cooker (Conran, 2002). It is a concept worked out by researchers from University of Illinois in the early 1950s to find the most sensible kitchen design for a four-person home. Esson (2006) also conducted an ergonomics study on the critical connection between the sink, cooker and refrigerator work areas in the kitchen.
The size of the kitchen and kitchen triangle are two main criteria in designing the kitchen space. These criteria have a strong indirect impact on the performance of the elderly especially in daily meal preparation. There are ‘pre’ and ‘post’ task in meal preparation. A longer walking distance in the ‘pre’ task will cause tiring to the elderly in completing the main task, and they will be exhausted when doing the ‘post’ task.
Elderly are commonly exposed to age-related decline such as locomotion. As far as the breakdown of physical impairment is concerned, the total daily walking distance during meal preparation in the kitchen should be reduced to a certain reasonable distance. This is crucial since there are many other instrumental activities of daily living (IADL) in the kitchen that need attention other than cooking. Therefore, the kitchen as a hub of the house should fit most of the user’s physical capabilities particularly to the elderly population.
36 Figure 2.5, Figure 2.6 and Figure 2.7 show three kitchen layouts and its different triangle shape. Each shape had different triangle length or distance. Whatever the kitchen layout looks like, the work triangle will automatically exist. Each triangle is invisibly created by the kitchen layout. It depends on how it can be made user-friendly, as well as considering it for later life arrangement.
Fig.2.5 ‘Gallery-type’ kitchen triangle
Fig.2.6 ‘L-type’ kitchen triangle
37 Fig.2.7 ‘U-type’ kitchen triangle
The National Kitchen and Bath Association, University of Minnesota (NKBA, 1992) has done research on kitchen triangle distances and compiled guidelines. In its guideline, the total triangle distance is 792.5 cm (26’ 0”). For Malaysian elderly, the total triangle distance should be shorter due to their smaller physical dimensions compared to the Americans and the difference in their walking step length.
2.5 Improving Residential Built Environment through Ergonomics
In order to improve elderly residential built environment, this ergonomic study is conducted. By improving comfort and enhanced elderly comfort perception through ergonomic could improve their task performance. Therefore applying ergonomic intervention could enhance comfort perception and improving residential built environment for the elderly population. The sub-topic below will explain the ergonomic approach heading to achieve the objectives of the study.
2.5.1 Current Design Guidelines for Elderly Residential
Elderly Residential Design Guidelines is not specified in Malaysia accept general building codes that are enacted by Public Work Department of Malaysia for general building construction (Rizal, 2014). The general building codes are widely applied by
38 architects, engineers, constructors and regulators but are also used for various purposes by safety inspectors, environmental scientists, real estate developers, subcontractors, manufacturers of building products and materials, insurance companies, facility managements, tenants, and others. This is another gap that could be filled through recommendation of the findings of this study.
2.5.2 Ergonomic Intervention that could Enhance Comfort Perception for Improving Residential Built Environment for the Elderly Population There are several ergonomic interventions that could enhance comfort perception for improving residential built environment for the elderly population. First, is by improving the workplace environment. Proposing the right kitchen temperature, humidity and brightness level will help the elderly in their task in the kitchen. It could also prevent them from kitchens’ accident. Second, propose the suitable kitchen triangle distance by referring the elderly anthropometry. Less walking will save their energy.
This will prevent the elderly from easily getting exhausted. Third propose physiological limitations upon performing certain task based on elderly physical ability. Energy expenditure or heart rate could be used to predict elderly physiological limitations. The results then could be compared with existing references. Fourth, improve the task design through postural analysis. Finally, provide the right equipment or furniture meeting the elderly anthropometry and physical requirements.
2.5.3 Improving Task Performance by Ergonomic Means
One of the ergonomic ways to improve task performance is through postural assessment (REBA) as mentioned in section 2.4.6. The process of coding and analysis starts from observing the task, selecting the posture for assessment, score the posture, process the scores, establish the REBA score and finally confirm the action level with the respect to the urgency for control measures. The improvement from the urgency for control measures could be changing the nature of a particular task by providing task aid such as
39 equipment to simplify the task, or even redesign the work layout to ensure worker’s comfort. Another way is evaluating the present task and working table height by considering the user’s anthropometric dimensions relate to the task he/she often faces discomfort and proposed the corrections through developing a workstation design model as explain in Section 2.5.4.
2.5.4 Developing anthropometric workstation design model for elderly in the kitchen
As the main problem identified, five anthropometric measurements are set to be collected. They are; stature height, shoulder height, waist height, arm reach forward and arm span. All measurements are statistically analysed to get the means, 5th Percentiles, 50th Percentiles and 95th Percentiles. The 50th Percentile of arm reach forward is used to set the width of the stove. Meanwhile the 95th Percentile of arm span dimension is used to set the length of the stove. The 5th Percentile of waist height became the lowest stove height and the 95th Percentile of waist height became the highest stove height. The other two measurements stature and shoulder height are used to estimate the elderly standing working envelope.
2.5.5 Prototype of Adjustable Working Table
Another expected outcome is fabrication of the adjustable stove height which is based on the elderly anthropometry dimensions as stated in section 2.5.4. The prototype consists of metal structures, laminated ply for the table-top and a hydraulic jack. A set of runner is designed to allow the up and down movements of the table-top. It is a manually adjusted working table. It can be locked to hold the elderly individually preferable height for the frying task session. A one meter steel ruler is attached to this adjustable table-top to measure the preferable height readings.
