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Work Station Evaluation: Bartending at Original Gravity

Ashley Anderson

Laura Jackson

Ryan Schabel

12/3/2013

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Table of Contents

Abstract 3

Introduction 4

Task Analysis 4

Anthropometric Assessment 7

Description of Tasks 7

Work-Relevant Dimensions 8

Existing Design Strategies Incorporated at the Workplace 8

Anthropometric Mismatches 9

Work-relevant Dimensions and Corresponding Percentile Values 10

Detailed Ergonomic Assessment 11

Back Pain/Risk Factor Assessment 11

Conclusion: Back Pain/Risk Factor 11

Static Elements of Workers Job Tasks 11

Conclusion: Static Elements of Worker’s Job Tasks 12

Upper Extremity Discomfort/ Risk Factor Assessment 13

Conclusions: Upper Extremity Discomfort/Risk Factor Assessment 13

Posture Assessment 15

Conclusions: REBA Assessment 15

Manual Materials Handling Assessment 16

Conclusion: Manual Materials Handling Assessment 17

Vision and Lighting / Hearing and Noise / Display Controls 18

Conclusions: Lighting and vision Conclusion: Noise Controls 19

Intervention Conception 20

Workplace Improvements 21

Appendix 22

References 29

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1.0 Abstract

The workplace of a bartender was evaluated for ergonomic risks relating to the workplace. Our team

visited the workplace of bar to take observe the worker performing his daily tasks in the workplace, record

the tasks via video and pictures, and to take measurements of the worker and his environment. Back pain

risk, static elements of the worker’s work, upper extremity risk, posture, manual materials handling, and

vision and lighting / hearing and noise / display controls were assessed. We found that the task,

“Grabbing and Placing Glasses Under the Counter”, created the most risk out of the tasks evaluated. The

risk for injury of the workers head/neck and back were the most concerning. Improvements and

modifications were suggested to improve the workplace.

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2.0 Introduction

We visited The Original Gravity Public House, where we observed the bartender (worker) performing

common work duties during a normal shift. During our observations, we identified a few different tasks

that were routinely performed, however there were two main tasks we noted that were particularly of

ergonomic concern. The first task was the Serving Process routine the worker engages in. This task can

be broken down into two subtasks: A) Filling glasses and B) Serving glasses. The second task

observed was the worker Grabbing and Placing Glasses Under the Counter, which involved putting

clean glasses away and retrieving them as needed. During our visit we identified areas that were reach

and fit problems for our worker relevant to the tasks, took and recorded the workers measurements for

our evaluation.

Our workers workplace is set up in a traditional pub arrangement. The back side of the workspace is a

wall with about twenty tap handles located about chest height for the average worker. Below the tap wall

is a low cabinet, with a stainless steel metal top that holds glasses and where the worker places after

being washed and grabs glasses to fill with beverages for customers. Located about six feet away and

directly across from this area, there is a low counter with a sink about (hip height of the average worker)

where the workers wash dishes. Back up to the sink and counter, is a serving table, where workers take

orders from customers and serve drinks. The floor is tile and does not have a rubber mat on top of it. On

the left side of the workplace there is an entrance to the kitchen. On the right is the register area and

storage for wine glasses and other items.

2.1 Task 1: Task Analysis

1 Company’s name: Original Gravity Public House

2 Employee’s name: Sopheak

3 Supervisor’s name: Rob Monroe

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4 Job title: Bartender

5 Work schedule: 20-24 hours per week

6 Department: Bartender (a subcategory of Food and Beverage

Services)

7 Job description: Serve beer to customers, wash dishes/glasses,

prepare food, serve food to customers, and clean

the workspace.

8 List of job objectives: Serve customers, maintain clean workspace a

clean supply of dishes.

9 List of tasks that encompass the

job:

Serving process (filling glasses with beer and

serving glasses to customers) and grabbing and

placing glasses under counter.

10 Essential functions of the job: Clean beer glasses, pour beer into glasses, and

serve beer to customers.

12 Any discomfort (ache, pain, etc)

experienced by the employee,

which the job exacerbates, or for

which the employee has had to

take off from work:

The employee described shin and calf pain in his

legs towards the end of his shift. No time has

been taken off from work for this issue.

13 Screening checklist - Indicate

which characteristics, listed on

the right, describe the job you

are studying:

Involves lifting or lowering objects.

Involves carrying objects.

Involves pushing or pulling objects.

Involves intensive use of the hands (such as a

craft or assembly work).

Involves a lot of standing.

Involves a little walking.

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14 Food and Beverage Service

Injury data from Bureau of Labor

Statistics website:

The data from the Bureau of Labor

Statistics measured workplace

injuries of Servers from the

following categories:

Fast food and counter workers,

waiters and waitresses, and non-

restaurant food servers.

Some of the injuries are similar to

the pain our worker expressed to us

during our evaluation, in which he

stated he experiences shin and calf

pain in his legs. Pain in the leg

areas are often related to injuries in

this industry according to the BLS,

with the most injuries occurring to

the head, back, shoulders, arms,

and knees.

When recommendations are given

in the Intervention Conception of

suggested improvements to our

worker’s workplace; taking special

care to monitor the head, back,

shoulder, arm and knee conditions.

Please see section, 6.0 for details.

Food and Beverage Service industry:

Amount of injuries and illnesses that involved lost

time (days away from work) in 2011.

Upper extremities:

Head: 730

Back: 2,850

Shoulder: 950

Arm: 1,280

Hand: 4,550

Wrist: 1,030

Lower extremities:

Knee: 1,610

Ankle: 1,110

Foot: 730

Bartender Specific:

Amount of injuries and illnesses that involved lost

time (days away from work) in 2011.

Upper extremities:

Head: 50

Back: 140

Shoulder: 20

Arm: 50

Hand: 470

Wrist: 70

Lower extremities:

Knee: 130

Ankle: 20

Foot: 60

Please see Table 1 in the appendix for each team member’s contribution and assignment to various

tasks.

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3.0 Anthropometric Assessment

The purpose of an Anthropometric Assessment is to determine the extent that the worker’s size fits with

the workspace conditions. When mismatches exist between the dynamics of a worker and their work

environment, there is an increased risk for work related injuries. In our observations, we saw two tasks in

particular which put the worker at the greatest safety risk. We then applied the work dimensions that

were most relevant to the workers task. Lastly, we noted any existing design strategies implemented by

the workplace, assessed the effectiveness of each, and made suggestions of more applicable strategies if

needed.

3.1 Description of tasks

Based on our observations, the following tasks were determined to put the worker at greatest risk for

injuries:

The first task was the Serving Process routine the worker engages in. This task can be broken down into

two subtasks:

A) Filling glasses, in which the worker holds the glass up to the tap height, then pulls down on the tap

handle to pour beer into the glass. This tasks encompasses forward reach, functional elbow reach,

hand length, standing elbow height, and standing height.

B) Serving glasses, which entails the worker standing and bending over the bar, and placing each glass

on the bar table. This tasks encompasses forward reach, functional elbow reach, standing height,

and hand length.

The second task observed was the worker Grabbing and Placing Glasses Under the Counter, which

involves putting clean glasses away and retrieving them as needed. While performing this task it requires

the worker to extend his arm, which involves elbow functional reach and forward reach while grabbing

the glass with the worker’s hand (hand length).

3.2 Work-relevant dimensions

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Based upon the observed job tasks of the worker, we determined the following dimensions to be most

relevant to to the job duties that the worker performs.

Elbow Functional Reach - Pulling the tap handle, holding the glass up to the tap, placing and retrieving

a glass on the bar, and reaching under the table for a glass.

Stature - Pulling the tap handle, holding the glass up to the tap, placing and retrieving a glass on the bar.

Hand Length - Grasping the glasses.

Standing Elbow Height - placing a glass onto bar and retrieving a glass from the bar.

Forward Reach - Pulling down the tap handle, holding the glass up to the tap, placing a glass onto bar

and retrieving a glass from the bar, and reaching under the counter for a glass.

3.3 Existing Design Strategies Incorporated at the Workplace

The workplace has designed a few strategies for reducing occupational risk factors. A portable iPad is

provided for placing orders and is equipped with an adjustable stand, which angles the screen towards

the worker. Since it is not fixed, the iPad stand can also be held to accommodate hand and neck

positions which bring the worker closer to a neutral posture. On the counter there is also a glass washing

device, which allows the worker to efficiently rinse glasses to remove soap residue and dust. This way

allows the worker to remain standing upright, which leave him in a more neutral position. (Please note,

these are general design strategies incorporated by the workplace and we did not observe any specific to

the tasks which we are evaluating).

Please see Table 2 in the appendix: DESIGN STRATEGIES, for a detailed breakdown of strategies

according each work element, what type of strategy was employed, and suggestions of more applicable

design strategies if they apply.

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4.0 Task 2: Anthropometric Mismatches

Anthropometric mismatches occur when there is a disparity between the worker and the work

environment, which negatively affects the workers ability to perform job related tasks correctly, resulting in

elevated risk of injury and decreased work productivity. These mismatches apply to fit and reach issues

which are caused by a lack of proper fit of workplace environment to the worker. These problems prevent

the worker from easily performing his job correctly leading to negative consequences. Another way

disparities are determined is by measuring the worker’s size and reach in relation to the work relevant

dimensions determined in section 3.2. The worker’s measurements are compared to that of the U.S.

population. A percentile is then calculated based upon where the worker falls in the spectrum relating to

the population and the calculated standard deviations from the mean. This further assists in detecting

anthropometric mismatches.

In relation to our worker, there are a few anthropometric mismatches we noted, specifically relating to fit

and reach problems in the workplace. During the serving process, to pour beer the worker must access

the tap handle, located above the midrange height of the worker’s forward reach, which forces him into

using an awkward upward reaching posture. Next, the worker must continue to hold his reach while he

pours beer into the glass from the tap. Also during the serving process, another disparity that occurs is

that the bar table the customers sit at is located over and past the sinks behind the bar. To serve beer to

customers, the worker must lean forward to reach over the sinks to place glasses onto the bar table.

Lastly, there is a fit issue involved with grabbing and placing glasses under the counter. Since the

glasses are stored under the counter, the location is very low to the floor and difficult to access because

the worker can not properly fit down into the low area. This action requires the worker to crouch down and

flex his back, then extend his arm forward while grasping the glass with a pinch grip.

Please see Table 3 in the appendix: ANTHROPOMETRIC MISMATCHES for a breakdown of if it is a fit

or reach problem and potential consequences associated with each problem.

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4.1 Work-relevant Dimensions and Corresponding Percentile Values

During our observation at the workplace, we measured dimensions of the the worker which were relevant

to the job tasks to determine his size in relation to other males the U.S. population. In the dimensions

measured, elbow height, stature, functional reach, forward reach,our worker falls into percentiles lower

than that of the average male. The one dimension which our worker lies above the 50th percentile is hand

length. This means, for most of these dimensions, he is of smaller size and stature than the 50th

percentile male in the United States. Hand length is relevant to the tasks because the worker must handle

materials like glasses very frequently. Stature, standing elbow height, forward reach, and forward

functional reach are relevant dimensions because a bartender must be capable of serving glasses onto

the bar table without too much discomfort. These dimensions are also relevant to the task of filling

glasses, as well. The Stature and forward functional reach are important to keep in consideration when

assessing the task of grabbing glasses under the cabinet.

Please see Table 4 in the appendix: WORK-RELEVANT DIMENSIONS and CORRESPONDING

PERCENTILE VALUES for calculations specific to each dimension.

Please see Table 5 in the appendix for team contributions.

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5.0 Task 3: Detailed Ergonomic Assessment

5.1 Back Pain/Risk Factor Assessment

Back pain risk factors were assessed after reading chapter two in the textbook Introduction to Ergonomics.

Risk factors for back pain were identified and applied to our chosen tasks for evaluation. The areas that

could potentially cause back pain are identified as: lifting objects from the ground in twisting positions,

nonneutral trunk postures held for > 10% of work cycle in repetitive jobs, bending and twisting, and

psychological factors.

Conclusion: Back Pain/Risk Factor

Back pain is a risk for our worker’s job. Intermittent lifting of objects from the ground in a twisting position,

non-neutral trunk postures held for 10% of the work cycle, bending and twisting, and psychological factors

are all risks of back pain and injury. Clearly, the task of Grabbing and Placing Glasses Under the

Counter has the highest risk because each of the risk factors for back pain/injury can be applied to this

task. As part of the Serving Process, the task of Serving Glasses appears less risky than Grabbing and

Placing Glasses Under the counter, but more risky than Filling Glasses. Three of the four risk factors

identified applied to this task and indicate this task should be evaluated in more depth. Only one of the

four risk factors applied to the task of Filling Glasses. This particular risk factor is called “Psychological

Factors” and only applies to the task when the worker is stressed, dissatisfied with work, avoiding pain,

etc. Therefore, this risk factor is only a risk sometimes and depends on our workers mental state.

Please see Table 6 in the appendix: BACK PAIN/ RISK FACTOR for details of the amount of risk

associated with movements of each job task.

5.2 Static Elements of Workers Job Tasks

Static positions and standing are both core aspects of a bartender’s job. Static positions are of concern

because they can contribute to fatigue and increase loads and forces on muscles and tendons, which

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increases risk of workplace injury. The vast majority of the worker’s shift is spent on his feet. While the

stagnant period of each task is relatively short in the case of our worker, it is the repetitiveness which

elevates risk of injury. Fortunately, there is a lot of movement due to the different locations of the tasks to

be performed, however there are still areas in need of improvement.

Conclusion: Static Elements of Worker’s Job Tasks

First, for the subtask of Filling Glasses, the worker must reach awkwardly upwards, bringing his body out

of a neutral position and placing strain on the lower back, neck, and shoulders. He must hold this position

while waiting for the glass to fill. Unfortunately no easy solutions exist for the repositioning of the taps and

their location in relation to small counter, however new taps which are positioned at a lower height

between the worker’s shoulders and hips could be installed to eliminate the need to reach upward.

Furthermore, the new taps could also extend out past the small counter, allowing the bartender to stand

in an upright position without having to reach over.

Next, for the subtask of Serving Glasses to the customers, the worker is required to engage in a posture

very similar to Filling Glasses. The worker must reach forward while leaning forward over the sink to

reach the serving table, which separates the worker from the bar table. This also forces the worker to

extend his neck. Although the serving table is positioned between the shoulders and hips of the worker,

his posture could be improved greatly by removing the sink from the area thus lessening his

overextended reach to access the serving table.

The task of Grabbing and Placing Glasses Under the Counter requires the worker to use a very

awkward posture. The counter is too low to the floor to reach under without causing strain on his back

due to the fact that he is forced to crouch and bend downwards to the floor. This counter is used to store

glasses which are clean and not in use. Therefore, the worker must use this posture to place clean

glasses under the counter and also to retrieve glasses as needed when the supply is running low.

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Major improvements can be made to aid the worker while in the static and standing positions. Additionally,

a floor mat would greatly benefit the workers, providing a surface softer than the current hard floor tiles.

Leg compression stockings would also aid in relieving the pain reported by our worker. Adjusting the

height of the glass-storage cabinet would also allow the workers to remain in a more neutral position,

reducing the risk for back pain.

Please see Table 7 in the appendix: STATIC ELEMENTS of WORKERS JOB TASKS for details of the

amount of risk associated with movements of each job task.

5.3 Upper Extremity Discomfort/ Risk Factor Assessment

The Moore and Garg’s Strain Index was best suited to assess our workers risk of Distal Upper Body

Disorders. This is due to the fact that he repetitively performs tasks that put him at risk. High risk tasks he

performs are filling glasses with beer, grabbing and placing glasses under the counter, and serving glass.

During these activities, he is placing strain on his upper extremities, thus this is why this test is

appropriate.

In explaining the use of this risk assessment tool to a manager, I would reiterate the above points of why

it is a good fit. I would let the manager know that while this worker is Filling Glasses, he is at some risk

of developing Distal Upper Body Disorders, which include primary muscle tendon and carpal tunnel

syndrome. For the Serving Glasses task, it is considered safe and he is at low risk, and for Grabbing

and Placing Glasses Under the Counter the risk is uncertain which means it is in a gray area. Right

now the worker is performing this task less than 1 hour a day and the manager should not allow the time

duration to not increase because anything over 1 hour will increase the risk rating to hazardous.

Conclusions: Upper Extremity Discomfort/Risk Factor Assessment

For the Serving Process task of Filling Glasses, the worker must reach his hand upwards to the beer tap.

Then he must press the glass against the tap, exerting pressure on his hand and wrist. When the glass is

near full, he rotates his wrist outward to pour out the excess beer foam. The intensity of exertion is

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somewhat hard, while he is performing one cycle of this task approximately >80% of the time during the

cycle is spent exerting pressure on the beer tap. A typical cycle lasts approximately less than 1 minute

and the worker spends about 2-4 hours in total per shift performing this task. The work pace falls within a

normal speed of motion and while he is performing the task there is a marked deviation of his wrist when

filling the glasses. The worker is at some risk of developing a Distal Upper Body Disorder from repetitively

performing this task.

For the Serving Process task of Serving Glasses to the customers, this requires less strain on the hand

and wrist than the prior task. The intensity of exertion is light. The time spend on this task that exerts

strain during a cycle is >80% and the total cycle last less than 1 minute and the task being performed

typically more than once per minute. There is a non-neutral wrist posture, the speed of work normal, and

the time duration of performing the task during a shift is between 2-4 hours. While some factors remain

constant, the difference with this task there is much less strain put on the wrist and hand. Thus, the task

is rated safe with low risk of injury.

For the Grabbing and Placing Glasses Under the Counter task, there is an uncertain level of risk

involved. The intensity of exertion is somewhat hard on the hand and wrist. The time spent on this task

exerting pressure on the wrists is 50-79% during 1 cycle. The total number of cycles the worker does in 1

minute can be between 4-8. There is a marked deviation due to the working having to reach awkwardly

under the counter to place glasses. The speed of work is rushed, but the worker is able to keep up with

the demand. The time duration of performing the task during a shift is typically less than 1 hour per day.

This the is rated as uncertain level of risk and is in the grey area.

Please see Table 8 in the appendix: UPPER EXTREMITY DISCOMFORT/ RISK FACTOR

ASSESSMENT for details of the amount of risk associated with movements of each job task.

5.4 Posture Assessment

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The REBA assessment tool was used to measure the risk of each task. This allowed us to easily identify

which parts of each task translated to higher risk as well as which tasks translated to higher risk. The

RULA assessment for each task is located at the end of the appendix.

Conclusions: REBA Assessment

The task of Grabbing and Placing Glasses Under the Counter received the highest risk measurement

with a score of 11. For the Serving Process tasks, Filling Glasses received a score of 2 and Serving

Glasses received a score of 3. After reviewing the scores of each of the tasks I have found that some of

the tasks should be modified to reduce the risk of injury to the worker.

Grabbing and Placing Glasses Under the Counter received the highest score REBA can give to a task.

This task involves the worker bending down to the floor with bent legs to place glasses into the cabinet.

This often involves twisting of the wrist to place the glasses in the correct area of the cabinet as well as

twisting of the head/neck to see where the glasses are to be placed. REBA states that this task is very

high risk and a change must be implemented. This is the first task we will improve in the workplace.

The Filling Glasses task received the lowest risk score of the three tasks evaluated. It had REBA score

of 2 which indicates a low risk in which change may be needed. This task involves holding a glass up to

the tap while pulling down on the tap handle with the other hand. The position that contributes the most

risk to the risk score is the arm position. The upper arm is bent between 45 degrees and 90 degrees and

the lower arm is bent between 60 degrees and 100 degrees.The tap is positioned near the average head

height so it does not require much flexion or extension of the neck. The feet of the worker are usually

positioned directly under the body with straight legs which is a relatively safe position for the worker. This

task will need little, if any, improvement.

A score of 3 was given to the task of the Serving Glasses task because it is considered low risk by

REBA. This task involves the worker bending over the bar at an angle between 20 degrees and 60

degrees to place a drink in front of the customer. The legs are usually straight and supporting the weight

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of the worker. The upper arm is positioned between 45 degrees and 90 degrees while the lower arm is

positioned between 60 degrees and 100 degrees. This task will need slight improvement.

The REBA tool has helped us understand which task produces the highest risk in order for us to

concentrate on improving that task first. The other tasks produce lower risk and will need less

improvement. We now know to focus the majority of our energy on the Grabbing and Placing Glasses

Under the Counter task because it desperately needs improvement for the wellbeing of the employees.

5.5 Manual Materials Handling Assessment

1991 NIOSH Lifting Equation Assessment

The NIOSH assessment equation provides recommended weight limits for items lifted and lowered with

the hands. The outcome of the equation is based on physical factors which are present in the workplace

involved with the task at hand. Once the Recommended Weight Limit has been calculated risk can be

assessed by using the RWL and the actual weight handled to calculate the Lift Index. The value of the Lift

Index is used to determine the risk of the task. The higher the Lift Index, the higher the risk of the task.

The lifting task to be evaluated is the grabbing and placing of glasses under the small counter.

Lift Index is calculated by dividing the actual weight handled by the Recommended Weight Limit:

LI = actual weight handled / RWL

The following is the equation for the Recommended Weight Limit:

RWL = LC x HM x VM x DM x AM x FM x CM

Based on the values obtained, the RWL equation is as follows:

RWL = 23 x 0.926 x 0.913 x .898 x 0.76 x 0.50 x 1.0

RWL = 6.63 kg

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The recommended weight limit for the task of grabbing or placing a glass under the counter is 9.95 kg.

Using the actual weight of the glasses, 0.3 kg, and the RWL, 9.95 the Lift Index is calculated as follows:

0.3 / 6.63 = 0.045

Some key assumptions and restrictions required for this assessment:

Smooth lifting followed

Stable, moderate object followed

Unrestricted lifting postures close to violated due to the constraints of the small cabinet

Two-handed handling close to violated due to only one hand necessary, but are two often used

Good traction for feet followed

Same risk for lifting/lowering followed

Asymmetric lifting up to 135° followed

Lifting/lowering for < 8 hours followed

Lifting/lowering only followed

No lifting/carrying aids used followed

Conclusion: Manual Materials Handling Assessment

Due to the very small weight of the glasses being lifted during this task, the Lift Index is very low. This

means that the weight of the glasses are not a risk factor for the lift. However, based on the multipliers of

the task, important features of the lift should be taken into consideration when redesigning the work area.

For example, the Asymmetry Multiplier and the Frequency Multipliers are closer to 0.00 than the other

multipliers. Therefore, these two factors should be considered before the others when redesigning the

lifting process, especially due to the awkward posture of the task.

Please see Figure 1 in appendix for a full list of calculations and measurements.

5.6 Vision and Lighting / Hearing and Noise / Display Controls

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While working in a bar environment workers often experience conditions of improper lighting and

excessive noise, which can cause eyestrain and hearing damage. We found this to be the case of our

worker too. While observing the work place, issues with lighting and noise were detected, while display

control issues were not.

The lighting luminance conditions were measured by looking for shadows over the worker’s work areas,

asking the worker if he suffers from eye strain, or has to squint to see. We were unable to measure for

illumination since we do not have a luminance meter. Using the available evaluation methods, we

detected problems that affect the workers vision and make it difficult to see at times.

The first issue we observed was high luminesces and glare from a large mirror in the workstation. There

are large mirrors covering the back wall with shelving racks containing beer bottles. Directly below the

mirror is the work counter made of shiny stainless steel metal. Sitting on this counter is the beer tap and

glass-washing device. There are overhead light fixtures with the lights angled toward the mirrors and

counter. The worker stands at the counter facing the mirrors when he is pouring drinks from the beer tap

and cleans glasses. The mirror and metal countertop cause high glare and reflection of light back into the

worker’s eyes. Additional glare is also caused from the light hitting the bottles and reflecting into the

mirror. The next problem was the use of a mobile visual display terminal (iPad). Since the device is

portable, the worker holds it at various angles and uses it in various areas around the workstation. This

causes glare from the overhead lights shining down on it, and depending on where he is standing relative

to the light, there are shadows falling across the screen making it dark and difficult to see.

During the observation, we auditorily monitored the bar’s noise levels that the worker is consistently

exposed to on a daily basis. We found potential noise issues that can cumulatively lead to hearing

damage over time. The bar atmosphere is loud with music playing in the background and people having

loud conversations to be heard over others around them. There is also noise from the dishwasher, and

the glasses and dishes make loud crashing and clinking sounds as they are moved or are hit against

other objects. These noise factors can cause reverberation and amplification. The noise from the glasses

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and dishes is of a higher pitch, sharp, and sudden in nature. The high pitch, along with the

unexpectedness variable may cause a startle response if great enough. If the noise it too great, it can

increase the worker’s stress level, decrease work performance due to loss of concentration and difficulty

hearing others in communications.

Conclusions: Lighting and vision

To improve the existing problems and reduce eyestrain, several steps can be taken. First, adjust the light

fixtures so the light is not pointed toward the mirror and is not glaring onto the mirror. Another option is to

use housing for the light bulbs, which cause the light to disperse out at a wider angle and not be as

sharply directed at one area. If these options are not available, the mirrors could be removed altogether.

Secondly, to fix the issue of the glare and the reflection of the iPad screen is to advise the worker to be

more cognizant of where he is standing while holding it to ensure that the light is not shining directly onto

the screen and that there is adequate lighting by making sure its not covered by a shadow.

Conclusion: Noise Controls

To help control noise level, care can be taken with handling of dishes and glasses to reduce loud noises.

The music level can be lowered and this will likely cause the conversation noise level to reduce also since

everyone will not need to talk over the music. These steps will help control the effects of noise for the

worker, lessening his chances for associated risks.

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6.0 Intervention Conception

Clearly, the task of Grabbing and Placing Glasses Under Counter needs to be improved. Raising the

cabinet to an average arm height would tremendously improve the risk to pain and injury. The worker

would no longer have to bend or twist their back or head/neck. This would keep the worker’s back and

head/neck in a posture closer to neutral for the entirety of the task, thus greatly reducing the risk. To

reduce potential risk factors associated with upper extremities, the worker should perform this task no

more than 1 hour of his total shift.

While observing our worker in the workplace, we noticed there were no rubber mats on the floor to

prevent (or reduce) back, foot, and leg pain during the job. A rubber mat would greatly improve the

working conditions of our worker, especially since lower leg pain is a symptom he described to us during

our observation.

Although the risk factor was not high, we believe a reorganization of the furniture in the workplace would

be beneficial to the workers while performing the Serving Glasses task. In the workplace there is a low

counter between the worker and the bar that the worker must reach over in order to give the customer

their glass of beer. This produces more arm and back strain than necessary. Short workers would need to

flex their spine more more than tall workers to reach over the two obstacles. Removing the low counter

between the worker and the bar would improve the workplace by reducing the flexion of the spine of the

workers back and neck.

Modifying the task of Filling Glasses will help reduce the risk of injury to the workers hand, such as

muscle tendon damage and carpal tunnel syndrome. As part of the task, the worker should not rotate his

wrist outward to pour out excess foam from the glass. As an alternative, he can let leave his stationary

and allow the glass to overflow to get rid of foam.

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To reduce the noisy working environment, workers should handle dishes and glasses with care to

noises levels. Also, by lowering the music level this will reduce the noise factor and help keep the

conversational noise level down also.

To reduce eyestrain, first, the light fixtures need adjusting so light is not shining directly on the mirror or

stainless steel counter top. Also, if possible the mirror should be removed altogether so there is not any

residual glare factor even with the lights adjusted. Next, workers should take care when using the

portable iPad to make sure light is not shining directly on it to reduce glare and that the screen is

obscured by shadows making it difficult to see.

Workplace Improvements

- Raise beer glass cabinet

- Add rubber mat to floor of workspace

- Reposition low counter between worker and the bar

- Rest periods and task rotation

- Fitness (trunk muscles)

- Back pain (when from muscles) can be prevented by redesign

- Lower music level

- Adjust lighting and/or remove mirror

Please see Table 9 in the appendix to see each team member contribution on various tasks to evenly

distribute workload on Task 3.

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Appendix

Table 1. Team Contributions on Task 1, Task Analysis:

Team members names: Roles and responsibilities in Task Analysis.

Ashley Took pictures, observed workplace, held group meetings, back

pain risk, and posture assessment.

Laura Recorded measurements, observed workplace, held group

meetings, upper extremity discomfort, and vision/lighting

hearing/noise display.

Ryan Took pictures, observed workplace, held group meetings, static

elements of workers work, and manual materials handling.

Table 2. DESIGN STRATEGIES:

Work element What design strategy was employed? (Design for fit, design for reach, design for the average, design for adjustability, design with multiple sizes, or anthropometry did not seem to be a consideration in the design; + explain)

Is there a more appropriate design strategy that you would suggest?

iPad holder can be angled towards the worker’s face

Design for adjustability This is designed appropriately for the users

iPad had a holdable case, so the worker could hold it with a flat palm, without using a pinch-grip

Design for average This is designed appropriately for the task

Glass rinsing device built into table

Design for average This is somewhat designed appropriately but workers would benefit if the device was taller to prevent too much wrist extension

Table 3. ANTHROPOMETRIC MISMATCHES:

23

Task Problem (Fit or Reach) Existing or potential

consequences associated

with this problem.

Holding glasses up to

pour beer from the tap.

Reach Shoulder, upper back, wrist,

and neck pain.

Pulling down the tap to fill

glasses.

Reach Shoulder, upper back, and

neck pain.

Leaning over the bar table

to take customer orders

and place glasses on the

table.

Reach Low back and shoulder

pain.

Grabbing glasses from

under the counter.

Fit Knee, low back, and

shoulder pain.

Table 4. Team Contributions of Task 2, Anthropometric Mismatches:

Team member: Roles and responsibilities for Anthropometric Mismatches:

Ashley Anderson measurement chart, design strategies, anthropometric mismatches

Laura Jackson measurement chart, design strategies, anthropometric mismatches

Ryan Schabel measurement chart, design strategies, anthropometric mismatches

Table 5. Work-relevant Dimensions and Corresponding Percentile Values:

Dimension Measurement Corresponding

24

Anthropometric

Percentile Ranking

Age 29 years old

Sex Male

Stature (standing height) 1701.8 mm, 5’ 7” 22.69 percentile

Hand length (from distal wrist crease to tip

of middle finger)

190.0 mm 63.01 percentile

Standing elbow height 1090 mm 43.01 percentile

Forward reach (middle finger to back of

shoulder)

790 mm 0.14 percentile

Elbow functional reach 1105 mm 42.85 percentile

Note: these percentiles were calculated based on population of U.S. adult males.

Table 6. Back Pain/ Risk Factor:

Filling Glasses Serving Glasses Grabbing/Placing Glasses Under Counter

25

Lifting objects from ground in twisting position

n/a n/a Worker lifts glasses from a cabinet near the ground. Intermittent and brief task that is performed every time a customer orders a beer.

Nonneutral trunk postures held for > 10% of work cycle in repetitive jobs

n/a Worker bends over bar to serve beer to customers. Intermittent and brief task that is performed every time a customer orders a beer.

Worker kneels or bends over to place glasses in the cabinet on the ground as well as lifts glasses from the cabinet to fill with beer. Intermittent and brief task that is performed every time a load of freshly washed glasses come out of the dishwasher.

Bending and twisting n/a Worker bends over the bar to serve beer glass. Intermittent and brief task that is performed every time a customer orders a beer.

Worker bends and sometimes twists to grab glasses from under the counter. Intermittent and brief task that is performed every time a customer orders a beer.

Psychological factors Work dissatisfaction, stress, avoidance of pain, etc. can increase the risk of back pain. Could be present for the entirety of the task.

Work dissatisfaction, stress, avoidance of pain, etc. can increase the risk of back pain. Could be present for the entirety of the task.

Work dissatisfaction, stress, avoidance of pain, etc. can increase the risk of back pain. Could be present for the entirety of the task.

Table 7. Static Elements of Workers Job Tasks:

Filling Glasses Serving Glasses Grabbing/Placing

Glasses Under

Counter

26

Posture Non-neutral, leaning

forward unconstrained

for 4 seconds, feet

shoulder width apart,

legs straight.

Non-neutral, leaning

forward constrained for

less than 4 seconds,

feet shoulder width

apart.

Worker bends

downward far and

extends arms to grab

glasses from or in

cabinet low to the

ground.

Factors Influencing

Posture

There is a counter

between the tap on the

wall and where the

bartender can stand,

which requires him to

lean forward while

reaching upwards with

his hands to pull down

on the tap.

Worker has to bend

forward to serve beer to

customers, due to the

sink being positioned

directly in front of the

serving table.

The cabinet is close to

the ground and

requires the worker to

bend over heavily.

Work objects

positioned between

hip and shoulder

height?

The beer taps are

positioned just above

shoulder height and

cannot be easily

relocated.

The bar height is

positioned between hip

and shoulder height.

No, the cabinet is

positioned very low to

the ground, below hip

height.

Sufficient toe space? Yes Yes Yes

Standing aids in

place?

No standing aids. No standing aids. No standing aids.

Additional information Workers take breaks

based on staff and

busyness. Reports of

leg pain in the shin and

calf areas.

Workers take breaks

based on staff and

busyness. Reports of

leg pain in the shin and

calf areas.

Workers must perform

this task when stock

glasses is running low

or when emptying the

dishwasher.

Table 8. Upper Extremity Discomfort/Risk Factor Assessment:

Filling Glasses Serving Glasses Grabbing/Placing

Glasses Under

Counter

27

Intensity

of

Exertion

Somewhat hard.

10-29

Worker must apply

force to beer tap, while

holding glass to fill it

while deviating wrist.

Light effort.

10-29

Worker must hold glass

firmly in hand and set

glass on table for

customer.

Somewhat hard.

10-29

Worker must apply

force to beer tap, while

holding glass to fill it

while deviating wrist.

Duration

of

Exertion

The total amount of

time spend on this task

is during one exertion

cycle is >80%.

The total amount of time

spend on this task is

during one exertion

cycle is >80%.

The total amount of

time spend on this task

is during one exertion

cycle is between 50-

79%.

Efforts

per

Minute

The cycle of exertion of

filling a glass lasts less

than 1 minute and is

typically not performed

more than 1 time per

minute, thus <4.

The cycle of exertion of

filling a glass lasts less

than 1 minute and is

typically not performed

more than 1 time per

minute, thus <4.

The cycle of exertion of

filling a glass lasts less

than 1 minute, and can

be performed between

4-8 times per minute.

Hand/ Wrist

Posture

There is a marked

deviation of wrist while

performing this task.

There is a non-neutral

wrist posture while

performing this task.

There is a marked

deviation of wrist while

performing this task.

Speed

of Work

The speed is of work is

considered to be within

the normal speed of

motion.

The speed is of work is

considered to be within

the normal speed of

motion.

The speed is of work is

considered to be within

the normal speed of

motion.

Duration

per

Day

The total amount of

time per day this tasks

consumes

is 2-4 hours.

The total amount of time

per day this tasks

consumes

is 2-4 hours.

The total amount of

time per day this tasks

consumes

is < 1 hours per day

Strain rating: 6.8 some risk 1.7 safe 4.5 uncertain

Table 9. Team Contributions of Task 3, Detailed Ergonomic Assessment:

Team Member: Roles and responsibilities for Detailed Ergonomic Assessment:

Ashley Anderson Back pain risk assessment, posture assessment

28

Laura Jackson Upper extremity discomfort/risk assessment, lighting/vision/hearing risk assessment

Ryan Schabel Static elements of workers work, manual materials assessment

Figure 1: Manual Materials Handling Assessment Measurements

LC - Load Constant - Recommended maximum load under optimal conditions = 23 kg

HM - Horizontal Multiplier - 25 (The optimal horizontal distance from ankles to object) divided by the

actual distance from midpoint between ankles to the hands used to lift object = 25 cm / 27 = 0.926

VM - Vertical Multiplier = 1 - (0.003 * | V - 75|) Where V is the height of the hands above the floor when

grasping the lifted object. VM = 1 - (0.003 * |46 - 75|) = 0.913

DM - Distance Multiplier = 0.82 + (4.5 / D) Where D is the vertical distance the object travels. DM = 0.82 +

(4.5 / 58) = 0.898

AM - Asymmetry Multiplier = 1 - (0.0032 * A) Where A is the angle between the worker’s body and the

object being lifted. AM = 1 - (0.0032 * 75) = 0.76

FM - Frequency Multiplier - considering number occurrences per minute(6),duration of work (between 1

and 2 hours) and vertical distance of lift in inches (less than 30 inches) determined by the Frequency

Multiplier Table. FM = About 6 occurrences per hour = 0.50

CM - Coupling Multiplier - Rating of coupling, based on the Hand-Container Coupling Classification table.

Because the glass is designed to be held, CM = 1

29

References

"Anthropometry and Biomechanics” (n.d.). National Aeronautics and Space Administration. .

Retrieved December 1, 2013.

"Case and Demographic Characteristics for Work-related Injuries and Illnesses Involving Days

Away From Work" (n.d.). U.S. Bureau of Labor Statistics. U.S. Bureau of Labor

Statistics, Retrieved November 20, 2013.

Bridger, R. S. Introduction to Ergonomics. Boca Raton: CRC, Print 2009.