ROSA

Rapid Oce Strain

Assessment

Michael Sonne, MHK, CK.

sonnemw@mcmaster.ca
Rapid Oce Strain Assessment
ROSA is a picture based posture checklist designed to quanCfy exposure to risk
factors in an oce work environment.
ROSA is modelled aHer other picture based checklists and chart scoring systems
such as RULA and REBA.
The goal of the ROSA process is to serve as a screening tool to idenCfy areas of
priority in large oce based organizaCons.

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ROSA - Usage
The end user will take a paper or electronic version of the ROSA score sheet with
them during an assessment.
The user selects postures that they observe, and records duraCons that are
reported by the person they are assessing.

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ROSA Results
Research has shown a correlaCon between discomfort levels and increasing ROSA
scores.
Inter and intra-rater reliability has also been shown to be good to very good.
Scores of greater than 5 are deemed to be high risk and the worksta7on
should be assessed further.

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ROSA Methods
The following are instrucCons on how to select postures using the ROSA checklist.
A full page example is at the back of this package, as well as a blank ROSA
assessment sheet that can be used to conduct assessments.

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Scoring within ROSA

Arms / Back rest

2 3 4 5 6 7 8 9

seat pan height /depth

2 1 2 3 4 5 6 7 8
3 2 2 3 4 5 6 7 8
4 3 3 3 4 5 7 7 8
5 4 5 4 4 5 7 7 8
6 5 5 5 5 5 8 8 9
7 6 6 6 7 7 8 9 9
8 7 7 7 8 8 9 9 9

SecCon A The Chair

Chair Height and Pan Depth

Select the posiCon of the seat height and chair pan. The rst posiCon in the leH column indicates the neutral
posiCon. This corresponds with a score of 1. The remaining posiCons are marked with increasing scores.
Those secCons with scores such as (+1) (ie., Insucient Space Under Desk) are addiCve scores. These can be
added on to the other scores. For Example, if the chair height is too high (2), and it is non-adjustable (+1), this
becomes a score of 3.

The score from the Chair Height is then added to the Pan Depth to receive the nal score from this secCon.
This score will correspond with the verCcal axis along the SecCon A scoring chart.
Scoring Examples Chair Height
Risk Factor Example Picture
Too low The height adjustment
cylinder is set to its lowest
height, and the worker is
tall.
Too high The knee angle is greater
than 90 degrees, and there
is pressure under the thigh.

Too high no foot contact The worker is using a stool

or lab height chair, so the
feet cannot physically
touch the oor.
Insucient space under The keyboard tray or a
the desk computer tower blocks the
legs from moving freely
under the desk.

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Scoring Examples Chair Depth
Risk Factor Example Picture
Seat pan depth too long There is less than 2-3 of
space behind the knee
when the person sits back
in the chair.

Seat pan depth too short There is more than 2-3 of

space behind the knee
when the person sits back
in the chair. This may
focus pressure on the
underside of the thigh, and
the thigh will not be
supported.

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 Arms / Back rest
2 3 4 5 6 7 8 9

seat pan height /depth

2 1 2 3 4 5 6 7 8
3 2 2 3 4 5 6 7 8
4 3 3 3 4 5 7 7 8
5 4 5 4 4 5 7 7 8
6 5 5 5 5 5 8 8 9
7 6 6 6 7 7 8 9 9
8 7 7 7 8 8 9 9 9

SecCon A The Chair, ConCnued

Arm Rests, Back Support and DuraCon of Sifng

Select the posiCon of the arm rests. Once again, the scores that can be added on to postures are indicated by
a (+) in front of the number. The scores from both the arm rest secCon and the backrest secCon combined will
amount to the score across the top axis on the scoring chart.

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Scoring Examples - Armrest
Risk Factor Example Picture
Armrests too low There armrests do not
support the forearms with
the elbows bent to 90
degrees

Armrests too high The shoulders are

shrugged when the
forearm is on the armrest
and the elbow is at 90
degrees.

Hard or Damaged Surface The armrest is made of a

hard plasCc/wood or
metal, and this creates a
pressure point on the
forearm. 10
Scoring Examples Backrest
Risk factor Example Picture
No lumbar support The chair has a at
backrest, possibly a plasCc
or board room chair. This
is usually seen in less
expensive models.

The chair may have lumbar
support and it is not
posiConed correctly in the
lower back
Angled too far back The backrest recline is too
far back, causing the
person to either sit
forward, or reach to the
keyboard.
No Back Support The worker is using a stool
or the backrest is not
posiConed against the back
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 Arms / Back rest
2 3 4 5 6 7 8 9
2 1 2 3 4 5 6 7 8
Seat Pan Height /Depth
3 2 2 3 4 5 6 7 8
4 3 3 3 4 5 7 7 8
5 4 4 4 4 5 7 7 8
6 5 5 5 5 5 8 8 9
7 6 6 6 7 7 8 9 9
8 7 7 7 8 8 9 9 9

1 5
The combined score from the arm and back rest secCon will then be compared on the horizontal axis against
the seat pan depth and height on the verCcal axis. The square in which the scores land will then be the score
for the chair.

To account for the duraCon that the worker spends in the chair per day, a score of -1 will be assigned if the
worker spends less than 1 hour a day in the chair throughout the day, or for less than 30 minutes
consecuCvely. If the worker spends 1-4 hours a day intermiiently, or between 30 minutes to 1 hour
conCnuously in the chair, the duraCon score is 0. If the worker spends more than 4 hours a day in the chair
intermiiently, or greater than 1 hour consecuCvely, the duraCon score will be +1. Add the duraCon score to
the chair score to receive your nal chair score.

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This will represent your score for secCon A, which will be used later to achieve a nal score for the oce.
 Monitor
0 1 2 3 4 5 6 7
0 1 1 1 2 3 4 5 6
1 1 1 2 2 3 4 5 6
2 1 2 2 3 3 4 6 7

Phone
3 2 2 3 3 4 5 6 8
4 3 3 4 4 5 6 7 8
5 4 4 5 5 6 7 8 9
6 5 5 6 7 8 8 9 9

SecCon B Telephone and Monitor

Select the scores as present related to the monitor posiCon for the worker. With this score, add 1 for use of
the monitor of greater than 4 hours per day intermiiently, or 1 hour consecuCvely. Add a duraCon score of 0
if the work is between 1-4 hours intermiiently, or 30minutes to 1 hour consecuCvely. Subtract 1 if there is less
than 1 hour of work done per day intermiiently, or less than 30 minutes consecuCvely. This score is then to
be used along the horizontal axis

Select a score related to the posiCon and usage of the telephone. Add in a duraCon factor of +1, 0 or -1 based
on the amount of Cme the worker spends on the phone per day. This score is then to be used along the
verCcal axis.

Compare the score between the horizontal and verCcal axis as done with the chair score. This score becomes
the SecCon B ROSA score, which will be used again later to receive the grand score. 13
Scoring examples - Monitor
Risk Factor Example Picture
Monitor too low The top of the screen is 30
degrees below the sifng
eye height causing neck
exion
Monitor too high The top of the screen is
above eye level, causing
the neck to be extended
while viewing the screen.
Neck twist The monitor is posiConed
to the side of the worker,
or dual screens may cause
the worker to rotate the
head back and forth.
Documents used no The worker has to ex and
document holder twist the neck in order to
view papers posiConed on
the desk
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Scoring Examples - Telephone
Risk factor Example Picture
Too far reach The phone is posiConed at
the back of the desk, and
when it rings, the worker
has to extend and bend
over the surface to grab
the handset.
Neck and Shoulder hold The worker has to use the
phone and computer at the
same Cme, and in order to
type, they will pinch the
handset between the neck
and the shoulder.

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 Keyboard
0 1 2 3 4 5 6 7
0 1 1 1 2 3 4 5 6
1 1 1 2 3 4 5 6 7
2 1 2 2 3 4 5 6 7

Mouse
3 2 3 3 3 5 6 7 8
4 3 4 4 5 5 6 7 8
5 4 5 5 6 6 7 8 9
6 5 6 6 7 7 8 8 9
7 6 7 7 8 8 9 9 9

SecCon C Keyboard and Mouse

Select a score based on the posiCon of the keyboard. If the keyboard is used for greater than 4 hours per day
intermiiently, or 1 hour consecuCvely, use a duraCon score of +1. For between 1-4 hours intermiiently, or
30minutes to 1 hour consecuCvely, use a score of 0. For 1 hour or less intermiiently, or less than 30 minutes
consecuCvely, use a score of -1.

Select a score based on the mouse posiCon. If the mouse is used for greater than 4 hours per day intermiiently, or
1 hour consecuCvely, use a duraCon score of +1. For between 1-4 hours intermiiently, or 30minutes to 1 hour
consecuCvely, use a score of 0. For 1 hour or less intermiiently, or less than 30 minutes consecuCvely, use a score
of -1.

Select a score by nding the intersecCon between the keyboard and mouse scores. This score will now be used to 16
retrieve a score for the peripherals, monitor and telephone.
Scoring Examples - Mouse
Risk Factor Example Picture
Pinch grip on mouse The mouse is small (such as
a notebook mouse) leading
to a pinching of the mouse.

Reach to mouse The mouse is out to the

side of the keyboard,
causing abducCon of the
arm. This may because the
person is small through the
shoulders, and the numeric
keypad causes further
mouse posiCon.
Dierent surfaces Mouse reach may also be
cause if the keyboard tray
is too small, and the mouse
is on a separate surface.

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Scoring Examples Keyboard
Risk Factor Example Picture
Wrists extended The tray may be angled, or
the legs on the back of the
keyboard may be up
causing the wrists to be
extended while typing.
DeviaCon while typing A small keyboard can cause
wrist deviaCon while
typing (ie, laptop
keyboards)
Keyboard tray too high When typing, the
shoulders are shrugged in
order to rest the arms or
hands on the appropriate
desk surface.

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 Monitor
0 1 2 3 4 5 6 7
0 1 1 1 2 3 4 5 6
1 1 1 2 2 3 4 5 6
2 1 2 2 3 3 4 6 7
Phone

Mouse and Keyboard

3 2 2 3 3 4 5 6 8
1 2 3 4 5 6 7 8 9
4 3 3 4 4 5 6 7 8
1 1 2 3 4 5 6 7 8 9
5 4 4 5 5 6 7 8 9

Monitor and Telephone

2 2 2 3 4 5 6 7 8 9
6 5 5 6 7 8 8 9 9
3 3 3 3 4 5 6 7 8 9
4 4 4 4 4 5 6 7 8 9
Keyboard
5 5 5 5 5 5 6 7 8 9
0 1 2 3 4 5 6 7
6 6 6 6 6 6 6 7 8 9
0 1 1 1 2 3 4 5 6
7 7 7 7 7 7 7 7 8 9
1 1 1 2 3 4 5 6 7
8 8 8 8 8 8 8 8 8 9
2 1 2 2 3 4 5 6 7 9 9 9 9 9 9 9 9 9 9
Mouse

3 2 3 3 3 5 6 7 8
4 3 4 4 5 5 6 7 8
5 4 5 5 6 6 7 8 9
6 5 6 6 7 7 8 8 9
7 6 7 7 8 8 9 9 9

Peripherals and Monitor/Phone Score

Using the score retrieved from the Monitor and Phone score in SecCon B, highlight the correct number
on the horizontal axis. Using the correct score retrieved from the monitor and telephone secCon,
highlight the correct number on the verCcal axis. Find the corresponding value within the scoring chart.

The value found from this scoring chart will now be used to nd a nal score by comparing it against the
value retrieved from SecCon A The Chair.

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 Arms / Back rest Mouse and Keyboard
2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9

seat pan height /depth

2 1 2 3 4 5 6 7 8 1 1 2 3 4 5 6 7 8 9

Monitor and Telephone

3 2 2 3 4 5 6 7 8 2 2 2 3 4 5 6 7 8 9
4 3 3 3 4 5 7 7 8 3 3 3 3 4 5 6 7 8 9
5 4 4 4 4 5 7 7 8 4 4 4 4 4 5 6 7 8 9
6 5 5 5 5 5 8 8 9 5 5 5 5 5 5 6 7 8 9
7 6 6 6 7 7 8 9 9 6 6 6 6 6 6 6 7 8 9
8 7 7 7 8 8 9 9 9 7 7 7 7 7 7 7 7 8 9
8 8 8 8 8 8 8 8 8 9
9 9 9 9 9 9 9 9 9 9

Peripherals and Monitor

1 2 3 4 5 6 7 8 9 10
1 1 2 3 4 5 6 7 8 9 10
2 2 2 3 4 5 6 7 8 9 10
3 3 3 3 4 5 6 7 8 9 10
4 4 4 4 4 5 6 7 8 9 10
Chair

5 5 5 5 5 5 6 7 8 9 10
6 6 6 6 6 6 6 7 8 9 10
7 7 7 7 7 7 7 7 8 9 10
8 8 8 8 8 8 8 8 8 9 10
9 9 9 9 9 9 9 9 9 9 10
10 10 10 10 10 10 10 10 10 10 10

The score from SecCon A is seen along the verCcal axis, and the score from secCon B and C is seen along the
horizontal axis. These scores are then combined through this nal scoring chart to receive the ROSA nal score from
the oce.

The ROSA nal score is broken into two areas: further assessment not immediately required, and further assessment
required as soon as possible. 20
 ROSA Example 1
2

2 2 1

3 1

2 1 2

3
-1

2 1 2

3 1

2 1 2 1

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1 1
Example 1
Arms / Back rest
2 3 4 5 6 7 8 9
seat pan height /depth

2 1 2 3 4 5 6 7 8
3 2 2 3 4 5 6 7 8 Chair Score = 5 +1 FOR DURATION = 6
4 3 3 3 4 5 7 7 8
5 4 4 4 4 5 7 7 8
6 5 5 5 5 5 8 8 9
7 6 6 6 7 7 8 9 9
8 7 7 7 8 8 9 9 9

Mouse = 2 + 1 = 3
Keyboard = 3 +1 = 4

Mouse and Keyboard

1 2 3 4 5 6 7 8 9
1 1 2 3 4 5 6 7 8 9

Monitor and Telephone

2 2 2 3 4 5 6 7 8 9
3 3 3 3 4 5 6 7 8 9
4 4 4 4 4 5 6 7 8 9
Monitor = 2 +1 = 3 5 5 5 5 5 5 6 7 8 9
6 6 6 6 6 6 6 7 8 9
7 7 7 7 7 7 7 7 8 9
8 8 8 8 8 8 8 8 8 9
9 9 9 9 9 9 9 9 9 9

Phone = 2 -1 = 1 22
Example 1

Mouse and Keyboard

Chair Score = 5 +1 FOR DURATION = 6 1 2 3 4 5 6 7 8 9
Arms / Back rest 1 1 2 3 4 5 6 7 8 9

Monitor and Telephone

2 3 4 5 6 7 8 9 2 2 2 3 4 5 6 7 8 9
seat pan height /depth

2 1 2 3 4 5 6 7 8 3 3 3 3 4 5 6 7 8 9
3 2 2 3 4 5 6 7 8 4 4 4 4 4 5 6 7 8 9
4 3 3 3 4 5 6 7 8 5 5 5 5 5 5 6 7 8 9
5 4 4 4 4 5 6 7 8 6 6 6 6 6 6 6 7 8 9
6 5 5 5 5 6 7 8 9 7 7 7 7 7 7 7 7 8 9
7 6 6 6 7 7 8 8 9 8 8 8 8 8 8 8 8 8 9
8 7 7 7 8 8 9 9 9 9 9 9 9 9 9 9 9 9 9

Peripherals and Monitor

1 2 3 4 5 6 7 8 9 10
1 1 2 3 4 5 6 7 8 9 10
2 2 2 3 4 5 6 7 8 9 10
3 3 3 3 4 5 6 7 8 9 10
4 4 4 4 4 5 6 7 8 9 10
Chair

5 5 5 5 5 5 6 7 8 9 10
6 6 6 6 6 6 6 7 8 9 10
7 7 7 7 7 7 7 7 8 9 10
8 8 8 8 8 8 8 8 8 9 10
9 9 9 9 9 9 9 9 9 9 10
10 10 10 10 10 10 10 10 10 10 10

The Grand ROSA score for Example 1 is 6.

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Reference
Sonne, M.W.L., Villalta, D.L., and Andrews, D.M., 2012. Development and
EvaluaCon of an Oce Ergonomic Risk Checklist: The Rapid Oce Strain
Assessment (ROSA). Applied Ergonomics 43(1), 98-108

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