Human Engineering Evaluation of Street Cleaners’ MSDs Symp-

toms

Presented by Kang Yoojeong

Kang SeoJeong

Nam SongEe

CAPSTONE DESIGN

contents

• Reason of subject selection

• The aim of project

• Survey from Street cleaners

• about MSDs

• Posture analysis of RULA

• Improvements

• Gantt chart

• Q & A

Reason for subject selection

Street cleaners work in a poor environment and

they have MSDs symptoms because of repetitive

work, rack of tools and work overload.

We will analyze the posture and will suggest how

to reduce MSDs symptoms.

Human Engineering Evaluation of Street Cleaners’ MSDs Symptoms

Way to reduce overloading of the amount of work

Preventive management of MSDs

The aim of project

About MSDsMusculoskeletal dis-orders (MSDs) are in-

juries or pain in the body's joints,

ligaments, muscles, nerves, tendons, and

structures that support limbs, neck and back.

MSDs can arise from a sudden exertion, or they can arise from making

the same motions repeatedly repetitive strain, or from

repeated exposure to force, vibration, or awk-

ward posture.Examples

carpal tunnel syn-drome Low back pain Tension

Neck Syndrome

Survey from street cleaners

Place : Seoul

Ages : All ages

Respondents : Street cleaners from Seoul

Total : 299

Survey from street cleaners

10% 27%

51%

12%

~39 40~49 50~59 60~

Ages

21%

17%29%21%

12%

below 4 years5 to 9 years10 to 14 years15 to 19 yearsover 20 years

Years of service

The highest ratio group of ages are 50s by 51%, people who have been working for 10years are 62%

Survey from street cleaners

7%

45%

44%4%

Physical discomfort Very hard Hard Normal Not hard

More than half of workers have physical pain.

Survey from street cleaners

Who

le b

ody

Hands

Arm

s

Shou

lder

s

Wai

stLe

gs

The

uppe

r lim

bs0

40

80

120

160

workers characteristic symptoms and MSDs

(multiple responses possible)

Posture analysis of RULA

Table A

An action of picking garbage up

up-

per

arm

lowe

r

arm

wrist posture score

1 2 3 4

wrist twist wrist twist wrist twist wrist twist

1 2 1 2 1 2 1 2

1

1 1 2 2 2 2 3 3 3

2 2 2 2 2 3 3 3 3

3 2 3 3 3 3 3 4 4

2

1 2 3 3 3 3 4 4 4

2 3 3 3 3 3 4 4 4

3 3 4 4 4 4 4 5 5

3

1 3 3 4 4 4 4 5 5

2 3 4 4 4 4 4 5 5

3 4 4 4 4 4 5 5 5

4

1 4 4 4 4 4 5 5 5

2 4 4 4 4 4 5 5 5

3 4 4 4 5 5 5 6 6

Score A

Table B

unbal-anced pos-ture : +2-

points

Neck

pos-

ture

score

trunk posture score

1 2 3 4 5 6

legs legs legs legs legs legs

1 2 1 2 1 2 1 2 1 2 1 2

1 1 3 2 3 3 4 5 5 6 6 7 7

2 2 3 2 3 4 5 5 5 6 7 7 7

3 3 3 3 4 4 5 5 6 6 7 7 7

4 5 5 5 6 6 7 7 7 7 7 8 8

5 7 7 7 7 7 8 8 8 8 8 8 8

6 8 8 8 8 8 9 9 9 9 9 9 9

Score BAn action of picking

garbage up

Table C

1 2 3 4 5 6 7+

1 1 2 3 3 4 5 5

2 2 2 3 4 4 5 5

3 3 3 3 4 4 5 6

4 3 3 3 4 5 6 6

5 4 4 4 5 6 7 7

6 4 4 5 6 6 7 7

7 5 5 6 6 7 7 7

8 5 5 6 7 7 7 7

Score

C

Score D

Score B (6)

+

Muscle (1)

+

Force (0)

=

Score D (7)

Score A (4) + Muscle (1) + Force (0) = Score C (5)

Grand Score (7)

=Action Level 4

Total RULA System

Wrist twist

Wrist

Lowerarm

Upper arm

Legs

Trunk

Neck

A

B

Muscular use Power+ +

+ +

Score C=

=

Posture score by using graph A

Power

Usescore

Ac-tion level

Score D

Muscular use

Posture score by using graph B

Posture score by using graph C

3

2

3

1

3

4

2

6

41

1

0

0

5

7

7 4

Action level

# The requirements for action into which the grand scores are divided is summarized into Action levels as follows.

Action level 1 : A score of 1 or 2 indicates that posture is ac-ceptable

If it is not maintained or repeated for long peri-ods.

Action level 2 : A score of 3 or 4 indicates that further investi-gation is needed and changes may be re-quired.

Action level 3 : A score of 5 or 6 indicates that investigation and changes are required soon.

Action level 4 : A score of 7 indicates that investigation and changes are required immediately.

Need to im-prove

Improvements

Improvement - 1

1. Using improved tools

- Minimize work-load by using working tools like these pictures.

Improvement - 1

Neck

pos-

ture

score

trunk posture score

1 2 3 4 5 6

legs legs legs legs legs legs

1 2 1 2 1 2 1 2 1 2 1 2

1 1 3 2 3 3 4 5 5 6 6 7 7

2 2 3 2 3 4 5 5 5 6 7 7 7

3 3 3 3 4 4 5 5 6 6 7 7 7

4 5 5 5 6 6 7 7 7 7 7 8 8

5 7 7 7 7 7 8 8 8 8 8 8 8

6 8 8 8 8 8 9 9 9 9 9 9 9

-We expect the posture score will de-crease by using improved tools.

Im-proved score B

Improvement - 1

1 2 3 4 5 6 7+

1 1 2 3 3 4 5 5

2 2 2 3 4 4 5 5

3 3 3 3 4 4 5 6

4 3 3 3 4 5 6 6

5 4 4 4 5 6 7 7

6 4 4 5 6 6 7 7

7 5 5 6 6 7 7 7

8 5 5 6 7 7 7 7

Score

C

Score D

Score B (3)

+

Muscle (1)

+

Force (0)

=

Score D (4)

Score A (4) + Muscle (1) + Force (0) = Score C (5)

Improvedgrand Score (4)

=Action Level 2

Action level 4(Change immediately) Action Level 2(Observation)

Improvement – 2

2. Street cleaners’ vocational education and prevention business

- Workers will be improved recognition through vocational education

- Education for preventing industrial accident

- Stretching before working time and after

Expected effect- Reduce spending money from industrial acci-

dent- Reduce risks by stretching

Improvement - 3

3. Appropriate work intensity

- Add another person to meet the needs.

- When they carry a heavy garbage, they work in teams of two.

- Make groups for each area.

Expected effect- It will decrease MSDs symptoms by reducing

work overload

Improvement - 4

5. Trash can improvement

– The appropriate placement of trash can.

– Make trash cans to collect the garbage easily.

Expected effect

- MSDs symptoms will be reduced.

Gantt chart

　 1주 2주 3주 4주 5주 6주 7주 8주 9주 10주 11주 12주 13주 14주

Organizing team　 　

Theme selection 　

Symptom Sur-vey on MSDs

　　

　

work measurement

　

interim report 　　

　

Data analysis and evaluation

　　

　

Improvement 　　

　

Final report 　 　 　 　 　 　 　 　 　 　 　 　 　 　

Q & A