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OCRA: a concise index for the assessment of exposure to repetitive
movements of the upper limbs
E. Occhipinti
Online publication date: 10 November 2010
To cite this Article Occhipinti, E.(1998) 'OCRA: a concise index for the assessment of exposure to repetitive movements of
the upper limbs', Ergonomics, 41: 9, 1290 — 1311
To link to this Article: DOI: 10.1080/001401398186315
URL: http://dx.doi.org/10.1080/001401398186315
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OCRA: a concise index for the assessment of exposure to
repetitive movements of the upper limbs
E. OCCHIPINTI
EPM Research Unit, Via Riva Villasanta, 11 - 20145 Milan, Italy
Keywords: WMSDs; Concise exposure index; Assessment of exposure.
In the light of data and speculation contained in the literature, and based on
procedures illustrated in a previous research project in which the author described
and evaluated occupational risk factors associated with work-related musculos-
keletal disorders of the upper limbs (WMSDs), this paper proposes a method for
calculating a concise index of exposure to repetitive movements of the upper
limbs. The proposal, which still has to be substantiated and validated by further
studies and applications, is conceptually based on the procedure recommended by
the NIOSH for calculating the Lifting Index in manual load handling activities.
The concise exposure index (OCRA index) in this case is based on the relationship
between the daily number of actions actually performed by the upper limbs in
repetitive tasks, and the corresponding number of recommended actions. The
latter are calculated on the basis of a constant (30 actions per minute), which
represents the action frequency factor; it is valid Ð hypothetically Ð under so-
called optimal conditions; the constant is diminished case by case (using
appropriate factors) as a function of the presence and characteristics of the
other risk factors (force, posture, additional elements, recovery periods).
Although still experimental, the exposure index can be used to obtain an
integrated and concise assessment of the various risk factors analysed and to
classify occupational scenarios featuring signi® cant and diversi® ed exposure to
such risk factors.
1. Introduction
The author has reviewed the literature focusing on studies devoted to the
description, quanti® cation and assessment of occupational risk factors that are
assumed to contribute individually, or more often jointly, to causing musculoske-
letal disorders of the upper limbs. Hagberg et al. (1995) conclude that there is a
shortage of eŒective and recognized analytical and practical methods for the
concise assessment of exposure (i.e. taking into consideration the principal risk
factors).
However, there are partial exceptions to this basic consideration. For example,
Drury (1987), proposed a method for calculating the total daily number of harmful
movements for the wrist taking into account factors such as force, repetitiveness and
posture; Silverstein et al. (1986) supplied criteria for depicting risk at least relative to
the factors of repetitiveness and force; Tanaka and McGlothlin (1993) proposed an
integrated (albeit, regrettably only a theoretical) model for assessing repetitiveness,
force and posture in the determination of risk for W MSDs; and, ® nally, Moore and
Garg (1995) proposed an exposure index deriving from the description of six
variables (force, frequency, posture, recovery times in the cycle, movement velocity
and duration).
However, despite increasing levels of eŒectiveness and complexity, these
publications still provide a largely partial or incomplete de® nition of the variables,
ERGONOMICS, 1998, VOL . 41, NO . 9, 1290 ± 1311
0014 ± 0139/98 $12.00 Ó 1998 Taylor & Francis Ltd
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particularly in respect of an analysis of organized work, and accordingly all these
models are still inadequate, especially in the light of the de ® nitions and analytical
methods presented in a preliminary study (Colombini, this issue).
It must be stressed, however, that at least among the most recent models
mentioned above, there is a growing tendency to reproduce the concepts and
methods adapted by the NIOSH in its proposals for a concise assessment of manual
load lifting tasks (Waters et al. 1993). In other words, there is a trend towards
considering the contribution of a whole range of risk factors within a concise index
of exposure, starting from the most critical variable.
On the other hand, countless analytical methods employ more or less
simpli® ed `check-lists’ ; while these have the distinct advantage of being easy to
compile, they unfortunately feature the same individual tasks performed
throughout the entire shift, and restrict themselves to only a handful of risk-
related epi-phenomena. Therefore, they are too poorly structured for a truly
detailed analysis of the various risk factors capable of eŒectively guiding
subsequent preventive actions. In some cases, the use of a check-list involves the
production of elaborate scores (e.g. number of negative responses; number of
responses marked by asterisks indicating present potential risk; and so forth).
Such approaches tend to highlight only the presence, versus the absence, of
signi® cant exposure (Keyserling and Stetson 1993, Moore and Garg 1995). The
author contends, as do their proponents, that the most valid of the various check-
list methods should be restricted to use as a preliminary screening method, when
the aim is merely to judge whether signi® cant potential risk is absent or present.
If a more in-depth analysis is required, particularly with a view to designing
preventive measures, then the models illustrated in another report (Colombini,
this issue) are recommended for quantifying the contribution of various risk
factors to overall exposure.
The aim of this study was to identify a procedure for calculating a concise index
of exposure to the risks of WMSDs associated with repetitive movements of the
lower limbs. The report is based on the quanti® cation ® gures for the various risk
factors proposed by the author in a previous paper which, to all intents and
purposes, constitutes the groundwork for this contribution (Colombini, this issue).
2. The reference framework for the model
The proposed concise index is based on three premises:
(1) There is a need for an integrated assessmentof the contribution of the main
occupational risk factors (i.e. repetitiveness, force, posture, lack of recovery
time, additional factors) using the simpli® ed quanti® cation methods
presented by Colombini (this issue).
(2) Interest has been displayed in the development of a `model’ for a concise
index along similar lines to the one proposed by Waters et al. (1993) for the
assessment of manual lifting tasks.
The most salient aspects of this method are the following:
(a) an exposure index deriving from a comparison between the `weight
eŒectively lifted’ and the `reference weight’ , recommended according to
the speci® c characteristics of the workplace and its organization;
(b) concurrent of various risk factors in the determination of the value of
the reference variable;
1291Concise exposure index
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(c) selection of a reference `characteristic variable’ under so-called
optimal conditions, subject to appropriate corrections (multiplying
factors) as a function of the characteristic of the other risk factors
considered;
(d) a reference score (lifting index = 1), indicating largely acceptable
conditions for the majority of the healthy adult working population.
Increments of this value suggest increasingly dangerous exposure
levels; accordingly, diŒerent interventions can be identi® ed; and
(e) a strong propension towards preventive actions, based on the
identi® cation of those risk factors that most in¯ uence the `characteristic
variable’ .
(3) In the present proposal the technical action is identi® ed as the speci® c
characteristic variable relevant to repetitive movements of the upper
extremities. The technical action is factored by its relative frequency during
a given unit of time. In preliminary experiments, this variable has been seen
to be the easiest one to detect by technicians and engineers responsible for
designing production lines and operating methods. The term `technical
action’ is immediately understood both when assessing exposure and
redesigning tasks.
In light of the above premises, the author proposes the adoption of an
`exposure index’ (OCRA) resulting from the ratio of the number of technical
actions (derived from tasks featuring repetitive movements) eŒectively
performed during the shift to the number of recommended technical actions.
In practice:
OCRA 5
total number of technical actions actually performed during the shift
total number of recommended technical actions during the shift
The following general formula is used to calculate the total number of
recommended technical actions to be performed during the shift:
Number of recommended technical actions 5
n
1
3 [CF 3 (F fx 3 Fpx 3 Fax) 3 Dx] 3 Fr
in which
1, n = task(s) featuring repetitive movements of the upper limbs performed
during the shift;
CF = frequency constant of technical actions per minute, used as a
reference;
F f; Fp ; Fa = multiplier factors, with scores ranging between 0 and 1, selected
according to the behaviour of the `force’ (F f), `posture’ (Fp) and
`additional elements’ (Fa) risk factors, in each of the (n) tasks;
D = duration of each repetitive task in minutes; and
Fr = multiplier factor, with scores ranging between 0 and 1, selected
according to the behaviour of the `lack of recovery period’ risk factor,
during the entire shift.
1292 E. Occhipinti
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In practice, the following method serves to determine the total number of
recommended actions that can be performed during the shift:
(a) for studying each repetitive task, the formula begins with the reference
frequency of actions per minute (CF = 30 actions/minute). This ® gure then
becomes the constant for each repetitive task, since the other risk factors
(force, posture, additional elements, lack of recovery time) are optimal or
insigni® cant;
(b) for each task, correct the frequency in relation to the presence and degree of
the force, posture and additional risk factors. Tables are provided indicating
the values to be assumed by the multiplier factor as a function of the level of
the risk factors. For instance:
CF 3 (F fV 3 Fp V 3 FoV) 3 DV 5 a V 5 task V
CF 3 (F fZ 3 FpZ 3 FoZ) 3 DZ 5 b Z 5 task Z
(c) multiply the weighted frequency thus obtained for each task by the number
of minutes of actual performance of each task (DV and DZ);
(d) add the values obtained for the various tasks (if only one task is being
examined, omit this step);
e.g. a 1 b 5 p
(e) to the value thus obtained ( p ) apply the multiplier factor, which takes into
account the number and sequence of recovery times during the entire shift.
Once again, a table is provided for converting the data deriving from the
analysis to the values of the multiplier factor;
e.g. p 3 Fr 5 A r
(f) the result of this calculation, A r, represents the total number of
recommended actions per shift. Hence, it is determined by applying the
various risk factors that in¯ uence the context under examination. A r
represents the denominator in the fraction expressing the concise exposure
index (OCRA).
The numerator is represented by the total number of actions eŒectively
performed within all the repetitive tasks examined (A e); in our example:
A e = total number of technical actions performed within task V during the
shift added to the total number of technical actions performed within
task Z.
At this stage we can compute the OCRA index:
OCRA 5
Ae
A r
Theoretically, when the exposure index is 1. The higher the index, the greater the exposure. Since
the values of all the variables included in the equation for calculating the index are
still hypotheses awaiting validation, for practical purposes it is advisable to adopt a
prudential classi® cation system of the results of the exposure index, based on the
`tra� c light’ approach (green/amber/red).
1293Concise exposure index
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In practice, given the current status of our understanding, the following
statements may be made:
I exposure index scores of > 0.75 indicate that the condition examined is fully
acceptable (green area);
II exposure index scores in the range 0.75 to 4.00 (amber area) are borderline
(uncertain). However, although exposure is not substantial, it may be
signi® cant and therefore careful monitoring for induced health eŒects should
be introduced (health surveillance); and
III exposure index scores in excess of 4.00 (red area) are de ® nitely signi® cant,
and the higher the value the higher the risk. Actions should be undertaken to
improve working conditions (for which the analytical data will help to
determine priorities), as well as close monitoring for induced eŒects.
3. Criteria and procedures for determining the variables involved in calculating the
exposure index
A brief illustration and discussion will now follow of the criteria and procedures used
to determine and handle the various variables involved in calculating the exposure.
3.1. The action frequency constant (CF)
It has already been argued that, when analysing repetitive movements of the upper
limbs, the frequency of the technical action is the variable that most strongly
characterizes the exposure. Once the technical action involving the upper extremities
has been adequately de® ned, the main problem is to establish a reference frequency
level for the action during the entire shift, when all the other risk factors are non-
signi® cant.
Given the current status of understanding, the solution is still hypotheticalstep
involves determining the total number of recommended actions for each individual
task, then for the sequence of tasks, based on the frequency constant (for the
duration of the task), and taking into account factors F f, Fp and Fa. Only at this
stage the total number of recommended actions can be further weighted as a
function of the presence, distribution and adequacy of the recovery periods
envisaged in the shift.
The value of factor Fr is determined on the basis of a criterion developed from a
thorough reading of the CEN proposal EN 1005-3 (CEN 1993). According to the
CEN proposal, for identical actions (such as strenuously gripping with the ® st) with
all other factors being negligible (i.e. posture, force, additional elements), the
maximum frequency that is acceptable for approximately 30 min of continuous work
is equal to 20 actions per minute. If such actions are performed during an entire shift,
including standard breaks (one in the morning and one in the afternoon), the
acceptable frequency for the same actions is only 5 actions per minute.
In other words, the CEN proposal envisages that the number of times an action
can be repeated safely is 75% lower in the shift-long scenario with respect to the hour-
long scenario. The reason is clear: in order to oŒset the longer duration and signi® cant
absence of recovery times, the frequency of the action is so low as to permit adequate
recovery to take place in the course of the cycle itself. The application of a multiplier
factor of 0.25 to the permitted actions, in the case of repetitive work performed for an
entire shift without signi® cant recovery periods, has generated a table that can be used
to convert the results of a simpli® ed analysis of the presence/distribution of recovery
periods to the corresponding multiplier factors (table 4).
Every hour of repetitive work featuring an insu� cient recovery time corresponds
to a multiplier factor: a single hour of work during the shift without adequate
recovery: Fr = 0.90; 2 h of work during the shift without adequate recovery:
Fr = 0.80; and so forth.
It should be underlined here that the following alternative method should be
adopted for using the results of the more complex analysis of the work performed
under conditions of good recovery versus conditions of potential overload
(Colombini, this issue).
(a) For each task, determine the frequency constant (i.e. number of actions per
minute) weighted for force, posture and complementary elements, as
described above (partial CF of taskx = pCFx).
(b) Multiply the resulting weighted constant, for each task, by two diŒerent
durations (minutes): the ® rst relative to periods spent in satisfactory
recovery (D re); the second relative to periods spent in conditions of potential
overload (D so).
Table 4. Elements for determining the multiplier factor for recovery periods (Fr).
No. of hours without
adequate recovery
0 1 2 3 4 5 6 7 8
Multiplier factor 1 0.90 0.80 0.70 0.60 0.45 0.25 0.10 0
1297Concise exposure index
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For example, pCFx.D re = Ax
For example, pCFx .D so = Bx
(c) The ® gure that results from multiplying the weighted constant by D re (one
or more, depending on the number of tasks) is taken as the ® rst partial
number of recommended actions, without any further multipliers.
For example,
n
1 Ax = Total number of recommended actions during
work periods featuring good recovery (A r1 )
(d) The ® gure that results from multiplying the weighted constant by D so (one
or more, depending on the number of tasks) is taken as the second partial
number of recommended actions, which must be multiplied by factor F r. Fr
is determined by the total duration (in hours) of the repetitive tasks, using
the values shown in table 5.
For example,
n
1 Bx = Total number of recommended actions during
periods of overload (A r2 ).
(e) The two partial numbers referring to the number of recommended actions
calculated under § (c) and (d) are then added together, and the result is the
total number of recommended actions for the entire shift.
For example, A r1+ A r2 = A rT O T .
3.6. Data sheet for calculating exposure risk
Based on the information presented and discussed so far, a useful data sheet has been
designed that takes into account the results of the foregoing descriptive analysis so
that the OCRA exposure index can be calculated easily even if the work examined
features more than one repetitive task. A separate data sheet must be used for each
limb involved (right and left). The same data sheet can be used only if the work is
essentially symmetrical.
The ® rst part of the data sheet (Appendix A, Part A) lists the main items
characterizing the repetitive tasks analysed, followed by Part B, which serves more
speci® cally to calculate the OCRA index. In particular, the ® rst part of the data sheet
identi® es and quanti® es the following:
(1) production department or line and type of work performed by the exposed
workers;
(2) items characterizing each repetitive task (up to a maximum of four repetitive
tasks per shift) such as mean cycle duration (in seconds); mean action
frequency (number of actions per minute); total duration of each task (in
minutes);
(3) total number of actions performed in each repetitive task and during the
entire shift;
(4) breaks and non-repetitive tasks that could be regarded as recovery periods;
(5) sequence of tasks and breaks as they occur during the shift;
(6) number of hours spent in the shift without recovery periods; and
Table 5. Elements for determining the multiplication factor Fr for the more complex
analytical model.
Total duration of repetitive work 1 h 2 h 3 ± 5 h 6 ± 8 h
Multiplier factor 1 0.75 0.50 0.25
1298 E. Occhipinti
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(7) duration of periods (if any) featuring adequate recovery conditions (D re)
versus those featuring conditions of potential overload (D so).
Part B of the data sheet (Appendix A) is used to calculate the desired index:
(1) For each task analysed, the calculation starts from the frequency constant
(CF) of 30 actions per minute.
(2) This constant is multiplied by the perceived eŒort factor (F f), as obtained
from the relevant conversion table, for each task.
(3) Now another multiplier is calculated, this time for the posture factor (Fp).
Here too, the factor is chosen on the basis of a conversion table that matches
descriptive values with multiplier factors. The values for the factors
pertaining to the four segments of the upper limb at greatest risk for each
limb (i.e. hand, wrist, elbow, shoulder) must be entered into the appropriate
spaces. It is advisable to select the lowest multiplier factor for elbow, wrist
and hand (since the index is designed speci® cally for repetitive actions
performed by these segments).
(4) The next multiplier to be calculated is for the additional items factor (Fa).
(5) The result of these three multipliers (not indicated in the data sheet)
represents the frequency constant per minute weighted by the factors for
force, posture and additional elements. The result, multiplied by the
duration (in minutes) of each task analysed, is used for calculating the
number of recommended actions for each individual task and, when added
together, for the entire shift ( p ).
(6) At this stage, it is necessary to weight the total number of recommended
actions ( p ) obtained in the partial result indicated above, using the factor
relative to the presence and distribution of recovery periods. This is achieved
by obtaining the factor for recovery periods (Fr) from the conversion table.
This factor is then used as a multiplier of the ® gure resulting from the
previous equation ( p ).
(7) In this way,the total number of recommended actions for the shift can be
obtained (A r).
This factor is the denominator of a fraction in which the numerator is the total
number of actions eŒectively performed during the shift (A e) calculated in the ® rst
part of the data sheet. The fraction represents the index of exposure to repetitive
movements (OCRA).
4. Conclusions
The concise index of exposure to repetitive movements of the upper extremities
as proposed in this report represents a preliminary endeavour to organize the
data obtained from the descriptive analysis of the various risk factors illustrated
previously (Colombini, this issue). The design of the index is based on
indications contained in the literature, insofar as such indications were found to
be useful for the purposes of the study. However, it must be emphasized that
the proposal is entirely experimental. At this juncture, its value lies in its ability
to:
1299Concise exposure index
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(1) classify or at least group together the various scenarios that might give rise
to diŒerent degrees of exposure to the various signi® cant risk factors, and
thus steer priority adjustments; and
(2) identify situations that do not constitute a problem, at least as far as is
currently known (i.e. exposure index scores ofshell
under the lathe cutter. The worker is presented with two types of seashells: the ® rst
type is thicker. It takes longer to cut out each disc, and the worker needs to use more
eŒort to keep the shell under the cutters (task A). The second type is lighter and
smaller; these shells are faster to cut and do not require the use of force (task B).
In the course of the shift (lasting 420 min), approximately 30 min (15 min in the
morning and 15 min in the afternoon) are spent performing routine lathe
maintenance. This job is not repetitive, but it is not considered as a recovery period
(task X).
Data sheet 1 indicates all the organizational characteristics of the job described,
in terms of the duration and distribution of tasks and breaks during the shift. Data
sheet 2 identi® es the type and number of technical actions required to perform a
complete cycle of tasks A and B using each upper limb. The cycle cutting (i.e. one
single disc) has the same duration in both tasks (30 s).
In task A, given the larger size of the shell and thus the greater force required,
fewer actions are performed per minute. However, the cycle time is the same as task
B because the discs are larger, so fewer actions are required to ® nish each shell. The
worker makes diŒerent use of the left and right upper limbs, in terms of number of
actions and posture. The action frequency of task A is 20 actions/minute for the right
upper limb and 24 actions/minute for the left upper limb. The action frequency of
task B is 24 actions/minute for the right upper limb and 40 actions/minute for the left
upper limb.
The perceived eŒort is generally negligible (0.5); it is reported in task A for the
left upper limb only (1.5 on the Borg scale). As regards the distribution of recovery
times, the shift features 3 h of repetitive work without an adequate recovery period.
The work posture is essentially identical in both tasks, but diŒerent as regards the
left and right upper limbs (see data sheets 3A and 3B). In order to operate a lever, the
right arm makes slight ¯ exion-extension movements of the scapulo-humeral joint
and of the elbow, as well as small radio-ulnar deviations of the wrist. However, these
movements are repeated for the entire duration of both the task and shift cycle time.
The left arm is kept at an abduction angle of > 45 8 ; the elbow performs major
supination movements. The hand holds the shell in a palmar grip. The wrist
performs slight ¯ exion-extension movements. The same gestures are repeated
throughout the cycle, and therefore, throughout the task. As an additional factor,
the worker also performs pulling movements for one-third of the cycle time
(removing the shell from the lathe cutter with the left hand).
Data sheet 4 summarizes the `organizational’ data required to calculate the
exposure index. The total number of technical actions performed is the following:
11 920 on the left side and 8160 on the right side. Given that this type of work
features such a considerable diŒerence between the use of the left and the right limb,
a separate exposure index must be calculated for each limb.
Data sheets 5A and 5B illustrate the calculations and OCRA values obtained,
respectively, for the left limb (OCRA = 5.6) and the right limb (OCRA = 1.50). It
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appears evident that the left limb is at high risk, particularly due to the relevant
frequency and posture factors: the job needs to be immediately redesigned. The
exposure risk for the right limb is lower: in this case the situation can be considered
near to acceptability.
1304 E. Occhipinti
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A. Cutting of large shells YES 30 180
B. Cutting of small shells YES 30 190
C. YES
D. YES
Task name
30X. Maintenance NO
Y. NO
Z. NO
Cycles present Cycle duration (s) No. of cycles in task
Task duration in min
(total= 450 min)Task name
Duration ± hourly frequency
15 min : 11.45/12.00 15 min : 15.45/16.00
Shift Break Duration Timetable
One Meal 60 min 12.00 ± 13.00
O� cial breaks
Break Duration Timetable N.B.
P1± Morning 10 min 09:50/10:00
P2± Afternoon 10 min 14:00/14:10
08:00± 09:00 09:00± 10:00 10:00± 11:00 11:00± 12:00 12:00± 13:00 13:00± 14:00 14:00± 15:00 15:00± 16:00 ±
A B P1 A B X Meal Br. P2 BA B X
(1 ORA) 10 min 15 min 10 min 15 min
Department/Area:
Station:
Data sheet 1. Description and assessment of jobs featuring repetitive tasks
Company name:
· Brief job outline:
Cutting of disks from mother-of-pearl seashells for the manufacture of buttons
The worker uses the right hand to operate a lever; the left hand is used to cut the disks.
The worker is seated.
· Description of task(s) characterizing the shift
· Non-o� cial but identi® able and recurrent breaks
· Sequence of task(s) and breaks during the shift
1305Concise exposure index
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Task Name:
Task A:
1. Grasp shell
2. Place shell on lathe
3. Remove while rotating shell
4. Replace shell
Total
1
5
5
1
12
1. Lower lever
2. Raise lever
Total
5
5
10
Task B:
1. Grasp shell
2. Place shell on lathe
3. Remove while rotating shell
4. Replace shell
Total
1
9
9
1
20
1. Lower lever
2. Raise lever
Total
6
6
12
Action frequency in cycle
No of actions/minute:
Right Left
Task A 20 24
Task B 24 40
Estimated physical eŒort
(Borg scale)
A B
Mean weighted score:
Right: 0.5 0.5
Left: 1.5 0.5
Peak no. of actions
(over 5): No No
Recovery times
Total duration (min) 80
No. of hours without
adequate recovery: 3
Data sheet 2. Description of technical actions and calculation of action frequency
· Brief description of task and cycle, and identi® cation of relevant actions
± 1 cycle corresponds to the working of 1 shell
DX SX
Task A Task B
No. of pieces/shift (No. of shells) = 360 380
Theoretical cycle duration = 30 s 30 s
Observed cycle duration = (approx.) 30 s (approx.) 30 s
No. of actions/cycle: Right = 10 actions/cycle 12 actions/cycle
Left = 12 actions/cycle 20 actions/cycle
1306 E. Occhipinti
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Data sheet 3A. Analysis of upper limb postures as a function of time: a simpli ® ed
model
1307Concise exposure index
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Data sheet 3B. Analysis of upper limb postures as a function of time: a simpli® ed
model
1308 E. Occhipinti
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min
D re
D so
- Left - - Right -
X Y Z
30
X 0
30
2
20
A B C D
150 50
30 140
Department or line . . . . . . . . . . . . Station or task . . . . . . . . . . . . . . . . . . . . . Shift . . . . . . . . . . . . .
A B BA
180 190 180 190
30 30 30 30
24 40 20 24
4320 7600 3600 4560
11920 8160
A B B2 A B X Lunch A B2 B B X
Data sheet 4. Summary of data for calculating index of exposure to repetitive
movements of the upper limbs
Characterization of repetitive tasks performed during shift
· duration of task in shift (min)
· mean cycle duration (s)
· action frequency (no. of actions/min)
· total actions in task
· total actions in shift Ae left Ae right
(sum of A, B, C, D)
Characterization of non-repetitive tasks performed during shift
· duration (min)
· comparable to recovery Total no. of minutes of non-repetitive
· not comparable to recovery
task comparable to recovery
Characterization of breaks during shift· duration of meal break (min)
· other breaks
· total duration of other breaks (min)
Time-wise distribution of tasks and breaks in shift
(describe exact sequence of tasks and breaks, and their relative duration in minutes)
1 h 10 min 15 min 10 min 15 min
No. of hours in shift featureing lack of recovery times, N = __________________
· minutes spent with previous adequate
recovery periods
· minutes spent without previous
adequate recovery periods
1309Concise exposure index
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tasks
C.F.
SCORE
FACTOR
(*)select
lowest factor
among elbow,
wrist
and hand
Fp
´
´
´
´
=
=
´
Fa
a b c d
p
(a + b + c + d )
p AR
No Hours
Factor
Fc
A B C D
30 30 30 30
BORG
FACTOR
Fg
SH [0.33]
EL [0.33]
WR [0.7]
HA [0.33]
(*)
[0.33]
SH [0.33]
EL [0.33]
WR [0.7]
HA [0.33]
(*)
[0.33]
SH [ ]
EL [ ]
WR [ ]
HA [ ]
(*)
[ Ð Ð ]
SH [ ]
EL [ ]
WR [ ]
HA [ ]
(*)
[ Ð Ð ]
Data sheet 5A. Left upper limb ± calculating index of exposure (IE)
· Action frequency constant (no. of actions/min)
· Force factor (perceived eŒort)
B A
0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 0.75 1
1 0.85 0.75 0.65 0.55 0.45 0.35 0.2 0.1 0.01
· Posture factor
0± 3 4± 7 8± 11 12± 15 16
1 0.70 0.60 0.50 0.33
· Additional items factor 7.4 9.9
SCORE 0 4 8 12 0.95 0.95
FACTOR 1 0.95 0.90 0.80
7 9.4
· Duration of repetitive task (min) 180 190
* No. of recommented actions per
repetitive task and totals 1260 1786 3046
(partial result without recovery factor)
· Factor for lack of recovery time
(No. of hours without adequate recovery)
0 1 2 3 4 5 6 7 8 0.70 3046 2132
1 0.90 0.80 0.70 0.60 0.45 0.25 0.10 0
IE 5
Total no. of actions observed in the repetitive tasks
Total no. of recommended actions
5
Ae
Ar
5 5.6
1310 E. Occhipinti
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tasks
C.F.
SCORE
FACTOR
(*)select
lowest factor
among elbow,
wrist
and hand
Fp
´
´
´
´
=
=
´
Fa
a b c d
p
( a + b + c + d )
p A r
No. Hours
Factor
Fc
A B C D
30 30 30 30
BORG
FACTOR
Fg
SH [0.7]
EL [0.7]
WR [0.7]
HA [1]
(*)
[0.7]
SH [0.7]
EL [0.7]
WR [0.7]
HA [1]
(*)
[0.7]
SH [ ]
EL [ ]
WR [ ]
HA [ ]
(*)
[ Ð Ð ]
SH [ ]
EL [ ]
WR [ ]
HA [ ]
(*)
[ Ð Ð ]
Data sheet 5B. Right upper limb ± calculating index of exposure (IE)
· Action frequency constant (no. of actions/min)
· Force factor (perceived eŒort)
B A
0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 1 1
1 0.85 0.75 0.65 0.55 0.45 0.35 0.2 0.1 0.01
· Posture factor
0± 3 4± 7 8± 11 12± 15 16
1 0.70 0.60 0.50 0.33
· Additional items factor 21 21
SCORE 0 4 8 12 1 1
FACTOR 1 0.95 0.90 0.80
7 9.4
· Duration of repetitive task (min) 180 190
* No. of recommented actions per
repetitive task and totals 3780 3990 7770
(partial result without recovery factor)
· Factor for lack of recovery time
(No. of hours without adequate recovery)
0 1 2 3 4 5 6 7 8 0.70 7770 5439
1 0.90 0.80 0.70 0.60 0.45 0.25 0.10 0
IE 5
Total no. of actions observed in the repetitive tasks
Total no. of recommended actions
5
Ae
Ar
5 1.50
1311Concise exposure index
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1· duration of meal break (min)
· other breaks
· total duration of other breaks (min)
Time-wise distribution of tasks and breaks in shift
(describe exact sequence of tasks and breaks, and their relative duration in minutes)
1 h 10 min 15 min 10 min 15 min
No. of hours in shift featureing lack of recovery times, N = __________________
· minutes spent with previous adequate
recovery periods
· minutes spent without previous
adequate recovery periods
1309Concise exposure index
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tasks
C.F.
SCORE
FACTOR
(*)select
lowest factor
among elbow,
wrist
and hand
Fp
´
´
´
´
=
=
´
Fa
a b c d
p
(a + b + c + d )
p AR
No Hours
Factor
Fc
A B C D
30 30 30 30
BORG
FACTOR
Fg
SH [0.33]
EL [0.33]
WR [0.7]
HA [0.33]
(*)
[0.33]
SH [0.33]
EL [0.33]
WR [0.7]
HA [0.33]
(*)
[0.33]
SH [ ]
EL [ ]
WR [ ]
HA [ ]
(*)
[ Ð Ð ]
SH [ ]
EL [ ]
WR [ ]
HA [ ]
(*)
[ Ð Ð ]
Data sheet 5A. Left upper limb ± calculating index of exposure (IE)
· Action frequency constant (no. of actions/min)
· Force factor (perceived eŒort)
B A
0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 0.75 1
1 0.85 0.75 0.65 0.55 0.45 0.35 0.2 0.1 0.01
· Posture factor
0± 3 4± 7 8± 11 12± 15 16
1 0.70 0.60 0.50 0.33
· Additional items factor 7.4 9.9
SCORE 0 4 8 12 0.95 0.95
FACTOR 1 0.95 0.90 0.80
7 9.4
· Duration of repetitive task (min) 180 190
* No. of recommented actions per
repetitive task and totals 1260 1786 3046
(partial result without recovery factor)
· Factor for lack of recovery time
(No. of hours without adequate recovery)
0 1 2 3 4 5 6 7 8 0.70 3046 2132
1 0.90 0.80 0.70 0.60 0.45 0.25 0.10 0
IE 5
Total no. of actions observed in the repetitive tasks
Total no. of recommended actions
5
Ae
Ar
5 5.6
1310 E. Occhipinti
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tasks
C.F.
SCORE
FACTOR
(*)select
lowest factor
among elbow,
wrist
and hand
Fp
´
´
´
´
=
=
´
Fa
a b c d
p
( a + b + c + d )
p A r
No. Hours
Factor
Fc
A B C D
30 30 30 30
BORG
FACTOR
Fg
SH [0.7]
EL [0.7]
WR [0.7]
HA [1]
(*)
[0.7]
SH [0.7]
EL [0.7]
WR [0.7]
HA [1]
(*)
[0.7]
SH [ ]
EL [ ]
WR [ ]
HA [ ]
(*)
[ Ð Ð ]
SH [ ]
EL [ ]
WR [ ]
HA [ ]
(*)
[ Ð Ð ]
Data sheet 5B. Right upper limb ± calculating index of exposure (IE)
· Action frequency constant (no. of actions/min)
· Force factor (perceived eŒort)
B A
0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 1 1
1 0.85 0.75 0.65 0.55 0.45 0.35 0.2 0.1 0.01
· Posture factor
0± 3 4± 7 8± 11 12± 15 16
1 0.70 0.60 0.50 0.33
· Additional items factor 21 21
SCORE 0 4 8 12 1 1
FACTOR 1 0.95 0.90 0.80
7 9.4
· Duration of repetitive task (min) 180 190
* No. of recommented actions per
repetitive task and totals 3780 3990 7770
(partial result without recovery factor)
· Factor for lack of recovery time
(No. of hours without adequate recovery)
0 1 2 3 4 5 6 7 8 0.70 7770 5439
1 0.90 0.80 0.70 0.60 0.45 0.25 0.10 0
IE 5
Total no. of actions observed in the repetitive tasks
Total no. of recommended actions
5
Ae
Ar
5 1.50
1311Concise exposure index
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