ERGONOMIC WORKSPACE DESIGN FOR MICROSCOPY IN LABORATORIES AT THE

INSTITUTE OF BIOLOGICAL SCIENCES, UNIVERSITY OF THE PHILIPPINES, LOS BAOS, LAGUNA

JOHN DERICK SANTOS MAGPANTAY RENZO ROBERT CEPILLO MANALO SARAH JANE HABAA SANCHEZ

JUNE 2015

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ACKNOWLEDGEMENT

It is when small efforts come together that great things happen. We would like to pay our

sincerest gratitude to the following for without them, this wont be possible:

To Dr. Maria Genaleen Q. Diaz, head of Genetics and Molecular Biology Division, for

granting us with the golden ticket;

To Maam Joan Adajar for patiently keeping up with our nuisances;

To BIO 131 students for not stopping us rummage through their work;

To Mang Caloy for his John Hancock;

To Maam Lizbeth for pulling us up every time were on the curb;

And most especially, to His Almighty, for the courage and wisdom to move forward.

To everyone who entrusted us with their insights, opinions and ideals, thank you! Hope that we

put your teachings to good use.

R.D.S.

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TABLE OF CONTENTS

Title Page i

Acknowledgement ii

List of Appendices iv

Abstract v

CHAPTER Page

1.0 Introduction 1

1.1 Problem Statement 3

1.2 Objectives 4

1.3 Project Scope 4

1.4 Project Work Breakdown Structure & Schedule 5

2.0 Review of Literature 6

3.0 Methodology 16

4.0 Results and Discussion 18

5.0 Summary, Conclusion and Recommendation 29

REFERENCES 32

APPENDICES 34

iv

LIST OF APPENDICES

Appendix Page

A REBA Worksheet (Middlesworth, 1989) 34

B RULA Worksheet (Middlesworth, 1989) 35

C Data gathered from the students 36

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ABSTRACT

Microscopy the use of a microscope is an essential activity in the study of

microscopic organisms, especially today with most researches venturing in the field of

microbiology. Past studies had revealed that while manipulating the microscope, the user may

experience symptoms that can lead to musculoskeletal disorders. In the University of the

Philippines Los Baos, the Institute of Biological Sciences has been producing several

graduates specializing in genetics and molecular biology. The study aims to investigate whether

the reviewed literature holds true for the laboratory setup in the institute. Moreover, the visual

environment is also inspected as it is a dominant factor in the possibility of experiencing eye

strain among the microscopists. Rapid upper limb assessment (RULA) and light survey are

used to evaluate the body posture of the students and the lighting of the room, respectively. The

scores for the postural assessment revealed that the perceived illumination on the working

surface followed the recommendation of Occupational Safety and Health Administration

(OSHA). While, RULA scores showed that the activity needs further investigation and that

changes in the work environment may be necessary. This can be achieved by designing a new

workplace for the microscope setup and adding auxiliary support for a more proactive approach

to mitigating the risks of MSD/CTD.

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Introduction

Microscope work is straining both to the visual system and the musculoskeletal system. Operators are forced into an unusual exacting position, with little possibility to move the head or the body. They are often forced to assume an awkward work posture such as the head bent over the eye tubes, the upper part of the body bent forward, the hand reaching high up for a focusing control, or with the wrists bent in an unnatural position.

Occupational Safety and Health Administration (Basic Microscope Ergonomics, n.d.)

The continuing research on prokaryotes has presented the scientific community with

major breakthroughs in fostering mans understanding of life on a microscopic level.

Prokaryotes are described as organisms having very simple cell structure: no nucleus or

organelles whose size typically ranges not more than 2 microns in diameter. Such organisms

as bacteria proved to be beneficial in food processing and drug manufacturing. Like most

autotrophs, cyanobacteria, formerly known as blue-green algae, have the ability to

photosynthesize, producing oxygen which is relevant in sustaining the ecosystem. Yogurts

which are gaining popularity as a dietary supplement contain lactobacillus which promotes

digestion (Microscope, n.d.). However, chronic exposure often leads to detrimental effects

normally on the health of the infected individual. Syphilis, chlamydia, and gonorrhea are some of

the sexually transmitted disorders (STDs) caused by bacteria. Other floral and faunal pathogens

have plagued several countries which resulted to the weakening of their socioeconomic milieu

(Microscope, n.d.). Thus, scientists proceed with the study of the micro-biome in general to

either further the development in the mentioned sectors, or prepare as rebuttal to the

devastation brought about by these plagues.

In investigating the microorganisms behavior, the scientist extensively uses the

microscope to be able to zoom in on the fine details beyond the normal capabilities of the

human eye, and render them on other imaging device like a camera (Abramowitz, 2003). The

activity of viewing an enlarged image of something minute while manipulating the microscope is

coined as microscopy (Kapitza, 1997). According to Sillanpaa and Nyberg (2010), microscope

works, by nature, require the person to maintain a static work posture which often lasts for

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long periods of time. In the context of ergonomics, it can be assessed as problematic in which

prolonged body fixations can gradually lead to the development of cumulative trauma disorders.

A study revealed that as high as 80% of microscopists experience musculoskeletal symptoms

like low-back pain, neck pain, and tension headaches (Haines & McAtamney, 1993; Kalavar,

Hunting, 1996; cited by Sillanpaa and Nyberg, 2010). Lee, Waikar, Aghazadeh, and Tandon

(1986) asserted that electromyographic examinations of microscopists showed that as short as

four hours of work, there has been a significant increase in muscle strain, about the neck and

shoulder region and in the back, augmenting by 25% to 65% (cited by Sillanpaa and Nyberg,

2010).

Aside from poor body posture, microscopy also causes eye strain with the concentration

needed in viewing through the ocular lens. An investigation done by Soderberg et al (1983)

highlighted the relationship between the eye function and visual strain in the population of

microscope operators at an electronics plant. On the average, 80% of them experienced

symptoms which strain the human visual faculty. Statistically, it has been found out that aside

from poor eye coordination and uncorrected astigmatism, the duration in which the operator

uses the microscope directly correlates with the manifestations of visual fatigue.

Table I. Prevalence of medical problems in microscopy

Anatomical Location Employee Percentage

Neck 50-60

Shoulders 65-70

Back (Total) 70-80

Lower Back 65-70

Lower Arms 65-70

Wrists 40-60

Hands and Fingers 40-50

Legs and Feet 20-35

Eyestrain 20-50

Headaches 60-80

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Table I shows the relative percentages of medical problems as reported by microscope

operators. Mostly stated that they experienced pain in the back region, followed by the

shoulders, lower arms, neck and wrist. The segments mentioned are located at the upper

portion of the human anatomy which proves its susceptibility over the lower extremity. Although

eyestrain scored the least minimum, it is a prospective precursor of headaches which racked a

relatively high number, almost tying up with back pains (Basic Microscope Ergonomics, n.d.).

The following data presented elicits an immediate study on the ergonomic intervention in

microscope work. With todays researches making profound use of the tool, it is necessary to

reduce the risk of developing CTDs and protect the microscopists in the practice of their

professions. The study aims to meet these requirements by modifying the workspace in

laboratories allocated for microscopy with due consideration to the ergonomic principles and the

anthropometry of the potential end users.

1.1 Problem Statement

Microscopy has the potential to cause the user discomfort and poses negative

health implications such as recurring pain in the neck, shoulder, back and suffering from

visual strain a study of Haines and McAtamney revealed 80% of microscope users

suffers from low-back pain, neck pain and tension headaches; and 80% of the

microscope operators of an electronic plant experienced visual strain from the

investigation of Soderberg.

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1.2 Objectives

The general objective of this study is to design a workplace inside laboratories at

the Institute of Biological Sciences that will be conducive for microscope work.

Specifically:

To reduce or eliminate hazards, while using the microscope, which can lead to

the development of cumulative trauma disorders

To minimize eye strain experienced by the students while using the microscope

.

1.3 Project Scope

The study focuses on the available compound microscope, Euromex Holland monocular

microscope, used in laboratory classes in the Genetics and Molecular Biology Division of the

Institute of Biological Sciences, University of the Philippines, Los Banos. The workplace design

is expected to fit microscope users who are within the samples age bracket and height range

since the researchers are limited to the student respondents as their subject, unable to account

for a more varied population. Thus, the anthropometric data gathered may not be as reliable to

use outside the study, or in other anthropometric designs.

The study chooses students specializing in genetics and molecular biology with the

frequency of implementing the microscope as a primary tool in their laboratory exercises. Other

institutions in the university are also feasibly to be selected as the venue of the study and it is

not necessary to limit the choice to a specific department. After all, the researchers aim to make

the study applicable to, if not all, most types of microscope work environment. With students

being accessible respondents, the study presents a more proactive approach to reduce, or

eliminate, possible hazards and risks associated with microscope work before the symptoms

manifest, as early as possible.

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1.4 Project Work Breakdown Structure & Schedule

The study takes place in the Institute of Biological Sciences, UPLB, Los Baos, Laguna with a project time frame of one

month, April 7 to May 6. The activities that the project will undertake are listed below with their corresponding schedule.

Fig.1.Gantt schedule chart for conduct of research study.

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2.0 Review of Literature

1.0 Ergonomics

Ergonomics is a science, indicating both of a study and a process, concerned with the

compatibility of the task to the individual who performs it and to the environment in which it is

performed (HSE, 2013; ILO, 1996, cited by Timoteo-Afinidad, 2010). This normally accounts the

persons capabilities and limitations, usually in terms of his/her physical, physiological,

biomechanical and psychological state, in the design of a workplace, equipment, machine,

tool, products, environment, and system (Fernandez and Marley, 1998; cited by Fernandez and

Goodman, n.d.). The term may be interchanged with human factors such as in defence and

transport industries (HSE, 2013), however, other textbooks provide a separate definition for the

latter whose focus differs slightly from that of ergonomics.

In the industry, ergonomics aims to determine the best work system which will effect

productivity increase with due consideration to the safety, health, and well-being of workers

(Fernandez and Marley, 1998; cited by Fernandez and Goodman, n.d.). However, the

applicability of the concept is not limited to manufacturing as it is also employed in services,

such as healthcare (Springer, n.d.), which render opportunities uniquely attributed to that sector.

To expound on the typical ergonomic problems found in the workplace, the Health and Safety

Executive (HSE, 2013) suggested the following inclusions, summarized in the table below:

Table II. Typical ergonomic problems (HSE, 2013)

Design of tasks

Fluctuating work demands

Low employee involvement in organizing work

Conflicting demand requirements

Decreased work pace due to badly designed machinery guards

Manual handling

Too heavy or bulky loadings

Frequent repetitive lifting

Awkward postures

Improper gripping

Uneven, wet or sloping work surfaces

Insufficient rest breaks

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Workstation layout

Items out of convenient reach

Inadequate work surface for legs

Inappropriate work surface height

Inadequate lighting

Improper adjustment of chairs

Managing the working day

Insufficient recovery time between shifts

Poor job scheduling

Excessive overtime

Safe to say, ergonomics is a process-oriented discipline which recognizes the growing

vitality of the human capital in the design of jobs as the individual directly interacts with work

interfaces (Timoteo-Afinidad, 2010). If ergonomic principles are well-infused in its intervention,

the benefits, as elaborated by Fernandez and Goodman (n.d.), are as follows:

Increase in productivity Improvement in workers safety and health Reduction of compensation claims Compliance with government regulations Improvement in job satisfaction Increase in quality of work Reduction of worker turnover Reduction of lost work time Improvement in workers morale Reduction of absenteeism rate

2.0 Anthropometry

Anthropometry, as defined by Del Prado-Lu (2007) and cited by Singh et al (2013), is

the science of measurement and the art of application that establishes the physical geometry,

mass properties, and strength capabilities of the human body. Its purpose is to record the body

size and shape of an individual in a systematic fashion with the use of caliper-like devices and

other graduated measuring tool (Freivalds, 2012; Singh et al, 2013). The validity of the

anthropometric data will depend on the accuracy of the measurement, the reliability of both the

tool and the person implementing the procedure, and the allowable degree of error that the

study is willing to compromise.

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The database access is crucial in optimizing the design of the workplace, and products

as to achieve an environment aligned with the ergonomic principles. Armstrong (1983), as cited

by Singh et al (2013), stated that acute and sub-acute cumulative trauma disorders (CTDs),

usually in the hand, wrist, and forearm, results from poor design and excessive use of hand

tools. Hence, many product designers and ergonomists make sure that the product, or the work

space, fits the structural size of the individuals body. Aside from that, factors like gender,

ethnicity, growth and development, secular trend, aging, social class, occupation, clothing, and

personal equipment (Fernandez and Goodman, n.d.) dictate to what extent the anthropometric

data can be deemed applicable.

2.1 Design for the average

Design for the average, as the name explicates, is a design approach in which the

measurement taken for a product dimension equals the 50th percentile of the anthropometric

data collected. According to Freivalds (2012), this is the cheapest method but the least

preferred for its inability to account a greater range of end users. Fernandez and Goodman

(n.d.) noted that it is only when the individual will use the product for a very short duration that

this design approach may be considered.

2.2 Design for extremes

Design for extremes is another design approach which often limits the maximum or

minimum value of a population variable to be considered (Freivalds, 2012). For example,

clearances, such as a doorway, should be designed for the tallest individual, considerably with

the 95th percentile stature. In contrast, door knob height should be within functional reach of the

smallest individual, normally with the 5th percentile stature (Fernandez and Goodman, n.d.).

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2.3 Design for adjustability

Also known as design for range, this is the most preferred design approach for its

accommodation of a wider range of end users (Freivalds, 2012). The measurements usually

vary from the 5th percentile to the 95th percentile, according to Fernandez and Goodman (n.d.).

This is commonly employed in the design of chairs, tables, desk, vehicle seats, steering

columns and tool supports (Freivalds, 2012, p. 188) however with greater flexibility attributed to

the product comes higher implementation cost. Thus, it is important to evaluate whether the

design will offset its cost on the long run before pursuing such approach.

3.0 Probability distributions and percentiles

Freivalds (2012) defined the kth percentile as a value such that k percent of the data

values, plotted in ascending order, are at or below this value and 100 k percent of the data

values are at or above this value (p. 187). To illustrate, a histogram plot of U.S. adult male

statures shows a bell-shaped curve as presented below:

Fig.3. Normal distribution of U.S. adult male statures (Freivalds, 2012)

Typically, the data can be normalized or approximated to the normal distribution,

continued Freivalds (2012), by the transformation

z=(x-)/

Where =mean

=standard deviation

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When normalized, the person can easily compute for the desired percentile value, using

the appropriate k and z values, as follows:

Table III. kth percentile vis--vis z value (Freivalds, 2012)

kth percentile 10 or 90 5 or 95 2.5 or 97.5 1 or 99

z value 1.28 1.645 1.96 2.33

Continuing with the example, it is computed that the mean stature for males in the U.S.

is 68.3 in. while the standard deviation is 2.71 in. (Webb Associates, 1978; cited by Freivalds,

2012). Given this, the 95th percentile male stature is computed as

68.3 + 1.645(2.71) = 72.76 while the 5th percentile male stature is

68.3 1.645(2.71) = 63.84

4.0 Cumulative Trauma Disorders (CTDs)

According to Fernandez and Goodman (n.d.), cumulative trauma disorders (CTDs) refer

to the physical injuries, which develop over a period of time as a result of repeated

biomechanical or physiological stresses on a specific body part. Symptoms for developing

CTDs, according to Kroemer (1989) and cited by Fernandez and Goodman (n.d.), include

discomfort, impairment, disability, or persistent pain in joints, muscles, tendons and other soft

tissues. These injuries are typically due to work and can develop over time with some reaching

years in span. It is almost impossible to accurately record the number of occurrence in a given

time frame without compromising the budget constraint and the validity of the result. To archive

an encompassing document which focuses on the prevalence of CTDs will be difficult for one

industry alone, especially with the specificities underlying each job type. Other factors which

should be considered include the high-paced improvement in available technology, an aging

workforce, physical weakening of new workers and reduction in worker turnover, increase in

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awareness and diagnosis, and the evolution of reporting methods (Fernandez and Goodman,

n.d.).

When an individual maintains an awkward posture while doing work for some time, or

applies a great amount of force repetitively, these instances are potential precursors to the

development of CTDs. Aside from these, exposure to multi-axial vibration also augments the

risk as it causes constriction of blood vessels, usually in the fingers, which impedes normal

blood flow, and leads to numbness and swelling of the hand tissues. There are three identified

major categories of upper extremity CTDs which include tendon disorders, neurovascular

disorders, and nerve entrapment disorders (Putz-Anderson, 1988; cited by Fernandez and

Goodman, n.d.).

5.0 Comfort vis--vis discomfort

Slater (1985), as cited by Ayachi et al (2014), defined comfort as a state of harmony

between humans and the environment in three dimensions: physiological, psychological and

physical. How man perceives comfort depends on the balance among the three in which

Pineau (1982), also cited by Ayachi et al (2014), asserted would be the optimal condition. The

notion, however, varies from one individual to another which makes it almost impossible to

establish a transcendent definition of the term. Thus, it has been investigated conceptually and

empirically in several contexts like product marketing (Vink and Hallbeck, 2012; cited by Ayachi

et al, 2014) to be able to achieve a working design that will maximize utility and over-all comfort.

The concept is perhaps better elaborated by looking into the meaning of its complement.

To address the varying notion of comfort over time and space, it is generally defined starting

from discomfort or rather the verge of discomfort. With the two terms being closely related,

some authors have considered them dichotomously in which the presence of one means the

absence of another, coining the term comfort/discomfort dimension (Zhang et al, 1996; cited by

Constantin et al, 2014). For example, some people find comfort in their personal companions,

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eliciting satisfaction and a sense of well-being. Clearing them from the situation implicates the

underlying discomfort which in turn invokes anxiety on the physical, or psychological state of the

individual.

6.0 Postural Assessment Methods

To gain understanding of the job tasks, interview the worker and observe the

movements and postures during work cycles. Postures to be evaluated should be based: 1) the

most difficult postures and work tasks (based on worker interview and initial observation), 2) the

posture sustained for the longest period of time, or 3) the posture where the highest force loads

occur. After the interview, it can be determined if only one arm or both sides should be

evaluated (Middlesworth, 1989).

6.1 RULA

Aside from REBA, RULA is a postural assessment method that is focused on the upper

limb part of the body. RULA (Rapid Upper Limb Assessment) was developed to provide a rapid

assessment of loads on the musculoskeletal system of operators due to posture, muscle

function and the forces they exert that may contribute to upper limb disorders (McAtamney &

Corlett, 1993).

RULA worksheet, provided in Appendix A is divided in 2 sections. Section A (left side) is

for arm and wrist, and Section B (right side) is for the neck and trunk. This segmenting of the

worksheet ensures that any awkward or constrained postures of the neck, trunk or legs which

might influence the postures of the arms and wrist are included in the assessment (Hignett &

McAtamney, 2000).

For Section A, evaluate Upper Arm, Lower Arm and Wrist Position using the figures on

the worksheet as a guide. If there is a twist in a wrist, add the necessary score. Locate Posture

Score in Table A using the scores given on steps 1-4 on the worksheet. Add Muscle Use Score,

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if applicable. Force/Load ranges are set, evaluate which range does the evaluated position fall

then add, having the total Wrist and Arm Score.

For Section B, evaluate Neck and Trunk Position. Assess the legs if it is supported or

not. Using these three scores, locate Posture Score in Table B. Add Muscle Use and

Force/Load, if applicable, having the total Neck, Trunk, Leg Score.

Final RULA Score is located in Table C, where Wrist & Arm Score for the row and Neck,

Trunk, Leg Score for the column. Assess the level of Musculoskeletal Disorder (MSD) Risk and

improve workplace to decrease the risk of MSD and other upper body disorders.

6.2 Other Methods

Other postural assessment methods that can be used to prevent Cumulative Trauma

Disorders are REBA and OWAS.

Rapid Entire Body Assessment (REBA) was proposed by Hignett and McAtamney as a

means to assess posture for risk of work-related musculoskeletal disorders (WRMSDs) (Hignett

& McAtamney, 2000; cited by Bernard, 2001).

REBA was established to develop a postural analysis system that is sensitive to

musculoskeletal risks in any type of tasks. The body is divided into segments that will be scored

individually, depending on the type of movement. It is provided in the worksheet, the scoring

system for muscle activity whether it is static, dynamic, rapid changing or unstable postures

(Hignett & McAtamney, 2000).

The REBA worksheet, provided on Appendix B is divided into two body segment

sections, labeled A and B. Section A (left side) covers the neck, trunk, and leg. Section B (right

side) covers the arm and wrist. This segmenting of the worksheet ensures that any awkward or

constrained postures of the neck, trunk or legs which might influence the postures of the arms

and wrist are included in the assessment (Hignett & McAtamney, 2000). Start scoring Group A

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postures first then Group B postures. There is a posture scoring scale and additional

adjustments that are needed to be considered and accounted for, for each region.

For Group A, assess Neck, Trunk and Legs Position of the posture of worker being

evaluated. Locate Posture Score in Table A using the 3 assessments stated before. If there is a

force/load, identify the score based on the ranges given in step 5 of the worksheet. Add the

scores for steps 4 & 5 to obtain Score A.

For Group B, evaluate the Upper Arm, Lower Arm and Wrist Position. Using the scores

for the 3 positions, locate the Posture Score in Table B. Add coupling score after evaluating how

the student handle things while in the evaluated position. Add the score for steps 10 and 11 of

the worksheet, named it as Score B.

Look up Posture Score in Table C using the scores from A and B. Add 1 if the evaluated

posture is held for a period of time, as described in the duration ranges of the worksheet, having

the Final REBA Score. Using the Final Score, identify the level of MSD (Musculoskeletal

Disorder) Risk and assess what actions to be done to improve the workplace.

On the other hand, OWAS (Ovako Working Posture Analysis System) method was

developed by Ovako Company in Finland and is used to estimate the degree of a workers

static load at workstation by analyzing the workers posture. It is an analytical method that has

a purpose of improving the condition at a workstation, ergonomically. The same as REBA, it

considers different positions of back, shoulders and legs, and take into account the weight lifted

by the worker (Grzybowska, 2010).

7.0 Photometry

Photometry is directly related to light surveying as it is the study of measurement of light

brightness with consideration to the physical properties of human vision. It mainly aims to

measure the brightness of visible light, as it appears to the human eye (Simpson, 2010).

15

The unit of measurement to be obtained from the light meter during a survey is lux,

which is the amount of illumination observed by an observer. It can be computed by dividing the

amount of visible light from the source, or luminous flux, by the area where the light is spread

out (Simpson, 2010).

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3.0 Methodology

The process of conducting the study comprised of three main procedures: data

collection, data analysis, and data evaluation.

Collection of data is always the first step in conducting a study because this will serve as

the building block of the research. The method used for this procedure is the use of a

customized questionnaire. The researchers gathered information on possible hazards faced by

microscope users and transformed them into simple questions answerable by Yes or No. This

is done to reduce the possibility of students overthinking the answer to a question with multiple

choices. Data gathered from these questions will be used for analysis to evaluate the current

postural conditions of the respondents. Their height and age are also asked in the form because

these will be used together with anthropometric data suitable in every condition to come up with

conclusions and recommendations. A sample of the questionnaire is shown below.

Fig. 3. Sample questionnaire for the students.

To supplement the data gathered from the questionnaires, the researchers recorded the

actual process of microscopy through the use of a video camera and tripod. The procedure was

done with the permission from the officials of the institute. The video recording will be done by

leaving the camera in the workplace while the students perform their exercise with the use of

microscopes. This is necessary to be done so as to make them feel at ease since there will be a

17

possibility that the students would feel awkward with the researchers recording them instead of

recording them while roaming around the area and will most likely gather inaccurate results due

to them not performing the work naturally.

Part of the evaluation of integrated data is light surveying. It requires the use of a light

meter which measures the illumination from a certain distance to the source of light. This will

serve as another factor that will determine if illumination levels in the workspace is sufficient for

the work. The main point of interest in the work environment for light surveying is the light

source of the microscope since this is where the point where the light hits and the main source

of illumination to the specimen. The light measured here will determine if it is sufficient for

viewing properly without strain or glare from the user. Other points in the workplace, like the

table surface where the students write their observations and the board where they refer to the

some notes and guidelines regarding their exercise, are also going to be considered in the

survey because it can possibly provide result about hazards experienced due to poor lighting.

To aid the researchers in light surveying, a steel tape will be used to measure the distances of

all mentioned points of interest in the workplace from the source of light.

Data gathered from the collection will then be integrated and studied by the researchers

to come up with results and reports on the current setting of the workplace. Postural

assessment methods are to be used to determine if risks are present in the posture of students

while working with a microscope. Various methods are available but Rapid Upper Limb

Assessment (RULA) is going to be used for the study. RULA focuses more on the upper body of

the student in which parts like the neck, trunk, arm, shoulder, and wrist will be assessed

individually. The video recorded by the researchers will be analyzed and used as reference for

the assessment of microscope work. These assessments will then be recorded on a worksheet

obtained from research. A sample worksheet for RULA is shown in Appendix 1. The results from

the assessment will also be used to validate the response of the students from the

questionnaires regarding the hazards they experience during microscope work.

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4.0 Results and Discussion

4.1 Survey

Fig. 4. Results gathered from the survey.

The researchers surveyed the students from classes which are using microscope in the

Institute of Biological Sciences. Complete data collected from the students are shown in

Appendix C. Before answering the main questions of the survey, the students are required to

write their height and age, which will be useful in this study. The data gathered from 18

respondents (6 Males, 12 Females), the average height of the students is 63.6 inches with the

mean age of 20 years old.

The students are asked about their experiences with their back, neck and shoulder

during microscopy (Questions 1, 2 and 5). As a result, 50% (9 out of 18) of the respondents said

they feel back pain, and 61% (11 out of 18) said they feel neck and shoulder pain.

1 2 3 4 5 6 7 8 9 10

Yes 9 11 5 5 11 15 3 15 16 17

No 9 7 13 13 7 3 15 3 2 1

0

2

4

6

8

10

12

14

16

18

No

. of

Res

po

nd

ents

19

Questions 3 and 4 are related to the experiences of their arms while using the

microscope. The data shows that only 28% (5 out of 18) said their upper and lower arm feel

tired.

Data gathered for question 6 show that 83% (15 out of 18) of the respondents said they

slouch while using the microscope. Whereas data for question 7 which is related to the hand,

illustrate 16% (3 out of 18) said they feel pain in their wrist.

The information gathered for the question 8, which is associated to the eyes, show that

83% (15 out of 18) of the respondents are experiencing eye-strain. While 89% (16 out of 18)

said viewing the microscope take more than a minute (Question 9). Lastly, 94% (17 out of 18) of

respondents said there are microscope work breaks provided (Question 10).

4.2 Light Survey

It can be seen from the light survey result shown in Fig. 5 that the light intensity in the

laboratory varies in the eight specified places in each of the workstation tables where the

microscopes are placed. Even though the placement of the lighting fixtures in the laboratory are

designed in a pattern, the result of the survey showed varying light intensity which may be

caused by:

Poor maintenance which cause in accumulation of dust in the fixtures,

Difference in wattage of the fixtures, and

Old fixtures

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647 641

614 573

754 701

682 626

634 617

629 608

602 616

568 538

BLACKBOARD

Fig. 5 Light survey result in the laboratory (in lux)

The Occupational Safety and Health Standards stated a minimum of 500 to 1000 lux

shall be provided as light intensity in fixtures where discrimination of fine details is involved

under conditions of a fair degree of contrast such as microscopy. Since the light intensity

measured from the laboratory ranges from 500 to approximately 800, the illumination of the

work environment is sufficient for microscope work and no problems are present in terms of

illumination.

4.3 RULA

The data gathering elapsed for two separate weeks, one for documenting the process

and another for the light survey. The students, the subject of the study, uses a Euromex Holland

monocular microscope which can be adjusted axially with the user by a pivotal knob. This is to

position the eyepiece on an angle comfortable with them. During an informal interview, the

students frequently mentioned that it takes them several hours to complete the laboratory

exercise which causes them eye strain, and acute pain in their back and neck, non-verbatim.

21

`

Fig.6. Students while using the microscope

The researchers judiciously selected five (5) images, those shown above, taken either

by a camera or a screenshot from the video recording. From there, they evaluated the body

posture of the students while using the microscope. Although it was stated to apply both REBA

and RULA in the postural assessment, the former was decided unanimously not to be used.

After all, within the duration of the activity, majority of the body segments involved are located

on the upper extremity. The values summarized on Table III were peer-reviewed and was taken

with deliberate judgment and consideration.

TABLE III. Results from RULA of five microscope users

Parameter Student

A B C D E

Upper Arm Position 2 1 1 2 1

Lower Arm Position 1 1 1 1 1

Wrist Position 2 2 2 2 2

Wrist Twist 1 1 1 1 1

Posture Score (A) 3 2 2 3 2

Muscle Use Score 1 1 1 1 1

Force/Load Score 0 0 0 0 0

Wrist and Arm Score 4 3 3 4 3

Neck Position 1 3 2 2 2

Trunk Position 2 2 2 2 3

Legs 1 1 1 1 1

Posture Score (B) 2 3 2 2 4

Muscle Use Score 1 1 1 1 1

Force/Load Score 0 0 0 0 0

Neck, Trunk and Leg Score 3 4 3 3 5

RULA Score 3 4 3 3 4

22

The students were sequenced as they appeared on Fig.4. Students A and D had their

upper arms positioned beyond the 20 limit while the remaining had otherwise. Although the

student can rest their arms on the table while rotating the knob, the problem lies with the stress

concentrating only on the part touching the surface. Other factors which contributed to the

variation are whether the arms were abducted, or the shoulders were raised. Same scores were

given for the lower arm position which ranges from 30 to 50 on both sides of the neutral

position. Also, the same grades were affixed to the wrist parameters in which the students

wrists were bended within the -15 to 15 limit with minimal twisting. The subject had to keep its

stance for several hours, evidenced by personal observation, informal interview, and survey.

The force load score across the samples is equivalent to zero because the microscope was

placed on the table and the students were not required to lift any sort of loading.

The scores for the neck position varied across the samples. This is where the sitting

height of the student will matter considerably the most. Some were taller than the average user

so they had to bow their heads to perform the experiment. If not, most leaned their body forward

while using the microscope. All received the same evaluation for trunk position. Although the

legs were supported by the chairs, the items can be later improve to add on the comfort agenda.

The previous scores for the two parameters muscle use and force load is also true for the

neck, trunk and leg analysis. Evaluating for the RULA score, it has been found that microscopy

indeed calls forth further investigation and that ergonomic intervention may be required.

4.4 Recommendation

After analyzing the result from the student survey, light audit, and Rapid Upper Limb

Assessment, the study proposed the following recommendations:

Fix position of the microscope

23

Place permanent markings, a straight line will do, about two to three inches from the

edge of the table. The base of the microscope will be positioned tangentially and perpendicular

to the line. The equipment cannot be screwed or attached permanently to the table since it will

be stored in a separate room every time the students finish their laboratory exercise. The

markings have to be light to contrast the tables surface color.

Modify the working surfaces inside the laboratory

The researchers recommend to modify the current microscope workspace inside the

laboratory. The main changes would be for the height of the table and the chair. Using the data

gathered from the respondents, specifically the height, researchers used the data from

Anthropometric measurement of Filipino manufacturing workers, written by Del Prado-Lu, as the

basis for the anthropometric data of the students. To check the validity of referencing to another

work, the study summarized the survey's result, as shown in Table IV, and compared it with that

from Del Prado-Lu's study shown in Table V.

Table IV. Summary of anthropometric measurements from survey

Gender

Standing height (cm)

Mean Std. Dev. 5th Percentile 95th Percentile

Male (n=6) 167.64 8.07 154.36 180.92

Female (n=12) 158.31 9.30 143.00 173.61

Male & Female (n=18) 161.42 3.85 145.31 177.52

24

Table V. Summary of anthropometric measurements from Del Prado-Lu (2007)

Anthropometric

measurement

Male (n=843) Female (n=962)

Mean 5th

Percentile

95th

Percentile

Std.

Dev. Mean

5th

Percentile

95th

Percentile

Std.

Dev.

Standing height 167.01 157.00 178.00 8.03 153.92 143.00 165.00 8.28

Eye height

(sitting) 73.36 67.00 80.00 3.83 68.38 62.00 74.00 4.85

The study computed for the percent error to quantify the accuracy between datasets. For

male's standing height, the % error for the mean, 5th percentile, and 95th percentile are 0.38,

1.68, and 1.64, respectively. For female's standing height, the % error for the mean, 5th

percentile, and 95th percentile are 2.85, 0.00, and 5.22, respectively. The values showed little

discrepancy between the two studies which implies that cross-referencing between studies is

valid and acceptable. By interpolating between the height of the students, both male and

female, and eye height while sitting of Filipino manufacturing workers, it is computed that the

average eye height of the students is 71.28 cm. The height of the current table is 77cm, the

plastic chair is 43 cm and the microscope is approximately 22cm tall, the computed

recommended table height for microscope use is 92.28cm. With this desired table height,

slouching of students while microscopy will be prevented and may reduce back and neck pains.

On the other hand, if adjusting the work table will not be possible, adjustable chairs must

replace the plastic chair and the stool. This type of chair is applicable to any variations in height

of the students wherein students can easily adjust the chair using a lever, placed underneath

the chair. The price this type of chair is at a minimum of P2,000 and below is an example of an

adjustable chair.

25

Figure 7. Recommended adjustable chair.

Install microscope armrest and seat wedges

Purchase microscope armrest and seat wedges to support the forearms and back of the

student. Fig. 8 and Fig. 9 show what the armrest and seat wedge look like. The armrest permits

the distribution of the arms weight. This is better explained by the inverse relationship between

pressure and surface area where maximizing the latter on which the force is acting will decrease

the stress projected on it. Seat wedges, on the other hand, support the back and other body

parts of the user while leaning forward instead of holding a static posture. Microscope armrests

are priced at $25.75, or approximately PhP1133 from alimed.com, while seat wedges are priced

at $11.95, or approximately PhP525.8 from amazon.com.

26

Fig. 8. Microscope armrest

Fig. 9. Seat wedge

Schedule microscope work breaks

Implement microscope work breaks where for every 15 minutes, students are

encouraged to close their eyes or focus on something in the distance (OSHA, 2011). This will

decrease the risk of experiencing eye strain, especially with the rooms lighting already at par

with the recommended level. To permit circulation of blood, the students can stand and stretch

for a while. OSHA (2011) recommends to do this every 30-60 minutes. This will be integrated in

the policy for laboratory exercises.

27

Educate the students for sustainability and continuous practice

For additional information on hazards and risks regarding microscope work, it is

recommended to include a brief background or orientation (i.e. included on introductory part of

the lab) on the possible risks of work-related health issues on the improper use of microscope in

every class that involves the use of microscope. This will inform the students about the possible

health issues they may develop from using microscope with improper methods.

Not only does the concern be placed on the body posture, the over-all comfort of the

students should also be taken into consideration. In detail, the following are the

recommendations on fostering comfort among students in the conduct of the activity:

Pad areas which support buttock, thighs and back

It is recommended that the chairs to be used in the laboratory for microscope work is

equipped with cushion pads in the back rest and seat to support the back and buttocks of the

students. This will reduce the back pain experienced by the students from the result of the

survey.

Provide foot rings or any other foot rest

Foot rings, as shown in figure 10, or any other foot rest may also be installed in the

chairs to provide temporary rest or break for the thighs and reduce the stress experienced. This

can be used when the user takes a break from microscope work where the feet are rested in the

rings to elevate the feet and reduce the stress experienced by the thighs from the force exerted

by its weight.

28

Fig. 10. Foot ring in a chair

Maintain laboratory at room temperature

For the room temperature, it is recommended to maintain the current temperature in the

laboratory since it is already furnished with an air conditioner and electric fan to maintain a

standard room temperature of 20 degrees Celsius.

Maintain lighting at recommended level

As previously mentioned, the illumination in the laboratory is sufficient for microscope

work without causing eye strain and other difficulties in observation. The light intensity in

different areas of the workstation tables are shown previously in figure 5 where it follows the

recommended illumination level standards set by OSHA, which is 500 to 1000 lux for work

requiring discrimination of fine details, such as microscope work.

29

5.0 Summary, Conclusion and Recommendation

Microscopy, defined as the use of microscope, has increasingly gained attention as the

scientific community undertakes research on the microbiome. These prokaryotic organisms are

essential in the continuing development on the field of food technology, pharmaceutics, and the

like. In microbiology, specialists tend to consume several hours in manipulating the equipment

because some experiments do not easily yield results. This is well-observed from the two-week

data collection at the Genetics and Molecular Biology Division in the Institute of Biological

Sciences, University of the Philippines Los Baos.

From the light survey results, it can be concluded that students doing microscopic work

do not experience eye strain due to insufficient lighting in the work environment. Even though

majority of the respondents from the survey answered yes to the question of whether or not

viewing specimens in the microscope is eye-straining, it can be said that the eye strain they

experience is not caused by the work environments illumination. One possible cause of eye

strain may be the nature of the work, which is looking or observing through a small opening and

closing the other eye in order to view the specimen properly. In order to reduce eye strain, it is

recommended to cover the other eye with a hand instead of closing it. In this way, the eye not

looking through the specimen does not exert force by closing and therefore not experiencing

strain.

To further support the students in their microscope work, they are suggested to work the

areas of the workplace table where light intensity is greater. This can help them view the

specimen better with the help of sufficient and proper amount of light.

From the rapid upper limb assessment, survey results and literature reviewed,

microscope work is indeed a potential precursor to the development of musculoskeletal

disorder, or cumulative trauma disorder in some reference, among the students. The data

gathered from the survey respondents illustrates that there is a relatively high proportion of the

30

respondents who experienced back, neck and shoulder pain. However, most students said that

they experienced eye-strain during microscopy. In addition from the five samples taken, all

RULA scores showed that there is a need to investigate further the activity and recommend

possible actions to minimize the risk.

Some changes can include either the workplace or the tool. However, replacing the

microscopes is not an option because it will entail high losses with the current set still not

obsolete. Thus, the best alternative is to modify the workplace by changing the dimensions of

the working tables and chairs, and implementing tools complimentary to the design changes. In

detail, the following are the recommendations on pacifying the symptoms associated with

MSD/CTD risk:

Fix position of the microscope by placing markings on the table

Increase the tables height to 92.28cm, or provide adjustable chairs.

Install microscope armrest and seat wedges

Schedule microscope work breaks for every 15 minutes to refocus eyesight and for

every 30-60 minutes to stretch

Educate the students on safety and risk associated with microscopy

Pad areas which support buttock, thighs and back

Provide foot rings or any other foot rest

Maintain laboratory at room temperature

Maintain lighting at OSHA recommended level

The study has focused largely on the postural assessment of the student microscopists

and the risk associated with it. However, recapitulating on the surveys result, many responded

that they experience visual strain while using the microscope even though lighting inside the

31

room is at par with OSHA-recommended levels. It would be viable to further research in

improving visual experience while performing microscope works.

Whether the ergonomic intervention is successful, it is substantial that as early as their

adolescence, future researchers be protected against hazards that can afflict them of these

disorders. The study would have been better if other anthropometric measurements are taken

instead of proportionating with values from previous datasets. Rest assured, the research would

be integrated into the long-running stream of scholarly literatures which focuses on the health

implications of microscopy.

32

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Appendices

Appendix A: RULA Worksheet (Middlesworth, 1989)

35

Appendix B: REBA Worksheet (Middlesworth, 1989)

36

Appendix C. Data gathered from the survey

Sample No.

Gender Height Age

Question No.

1 2 3 4 5 6 7 8 9 10

M F Y N Y N Y N Y N Y N Y N Y N Y N Y N Y N

1 1 65.0 28 1 1 1 1 1 1 1 1 1 1

2 1 63.0 19 1 1 1 1 1 1 1 1 1 1

3 1 62.0 19 1 1 1 1 1 1 1 1 1 1

4 1 56.7 19 1 1 1 1 1 1 1 1 1 1

5 1 64.0 21 1 1 1 1 1 1 1 1 1 1

6 1 64.0 20 1 1 1 1 1 1 1 1 1 1

7 1 70.0 20 1 1 1 1 1 1 1 1 1 1

8 1 58.0 20 1 1 1 1 1 1 1 1 1 1

9 1 62.0 20 1 1 1 1 1 1 1 1 1 1

10 1 62.0 21 1 1 1 1 1 1 1 1 1 1

11 1 59.4 19 1 1 1 1 1 1 1 1 1 1

12 1 69.5 20 1 1 1 1 1 1 1 1 1 1

13 1 66.0 21 1 1 1 1 1 1 1 1 1 1

14 1 62.0 20 1 1 1 1 1 1 1 1 1 1

15 1 61.8 19 1 1 1 1 1 1 1 1 1 1

16 1 71.0 18 1 1 1 1 1 1 1 1 1 1

17 1 65.0 18 1 1 1 1 1 1 1 1 1 1

18 1 62.5 18 1 1 1 1 1 1 1 1 1 1

Total 6 12 9 9 11 7 5 13 5 13 11 7 15 3 3 15 15 3 16 2 17 1