Basic Concepts
In the Kinematics Solver dialog box, the Optimize
Criteria option allows you to choose to optimize the posture according to either Postural Score or RULA Analysis. This option is in effect when IK
mode or Reach mode uses the IK solver to resolve a constraints update. By default,
None selects. Only one of the three options can be
available at the same time. When the Postural Score is on, the IK internally refers
to the Postural Score. It tries to find the best score for each segment involved in the IK chain that manipulates.
This requires you to apply preferred angles to these segments, before using the
optimize capability. If no Preferred Angles applies to the Manikin, then the Postural Score option grays out
and is unavailable. Select RULA, then IK uses RULAs internal preferred angles
calculation. That leads to a global score when RULA uses inside the appropriate
Human Activity Analysis command. To lead to an optimized posture of the involved
segments during manipulation involving the IK solver. Here you do not need to
explicitly apply Preferred Angles to the segments of the Manikin.
Side
Use the two to select the side,
Left or
Right of the manikin that is analyzed.
Parameters
- RULA Parameters
-
Use the options in this zone to specify settings that cannot be define automatically.
- Posture
- Three types of postures are:
- Static
- Intermittent
- Repeated
Select the choices that best describe the worker's situation.
- Repeat Frequency
- Uses this parameter to determine the task frequency. Two choices are available:
- Fewer than 4 times per minute.
- More than 4 times per minute.
- Arm supported/Person Leaning.
- Arms are working across the midline.
- Confirm balance.
Select one or more of these options to provide additional
information that may affect the output of the RULA analysis.
- Load
- Use this field to specify the weight of the manipulated object. Select the arrows to
increase or decrease the weight or use the keyboard to directly enter a
value into This field.
RULA Score
- Score
-
There are two modes for the score display: basic mode and
advanced mode.
- Basic mode
- The data displayed in This mode is the final score
accompanied by a colored zone. The color of This zone changes from green to red
according to the final score.
The RULA analysis examines the following risk factors:
number of movements, static muscle work, force, working posture, and time
worked without a break. All these factors combine to provide a final score that
ranges from 1 to 7.
- 1 and 2: (Green) Posture is acceptable if it maintains or repeats for long periods of time.
- 3 and 4: (Yellow) Further investigation requires and changes may require attention.
- 5 and 6: (Orange) Investigate and changes require soon.
- 7: (Red) Investigate and changes require immediate attention.
- Use
More
to switch from the basic mode to the advanced
mode.
- Advanced mode
- The data displayed in the basic mode is also displayed in the advanced mode. The advanced
mode, in addition, also displays the intermediate scores. Some
of these scores obtain by subjective values. In the basic mode,
these values are automatically define to default, in the
advanced mode you can change these values. The score modifies to
reflect these new values.
Details
|
[+] |
Upper Arm: |
1 |
|
[+] |
Forearm: |
1 |
|
[+] |
Wrist: |
1 |
|
[+] |
Wrist Twist: |
1 |
|
|
Posture A: |
1 |
|
|
Muscle: |
1 |
|
|
Force/Load: |
0 |
|
|
Wrist and Arm: |
2 |
|
[+] |
Neck: |
1 |
|
[+] |
Trunk: |
1 |
|
|
Leg: |
1 |
|
|
Posture B: |
1 |
|
|
Neck, Trunk, and Leg: |
2 |
|
Use Less to switch back to the basic
mode.
- Details
- The Details section that is displayed when you click More
presents the score obtained for each section and used to
calculate the final RULA score. Edit the parameters of six of
these segments:
- Upper arm: Shoulder elevation, Arm abduction.
- Forearm: Arm rotation.
- Wrist: Wrist deviation.
- Wrist twist: Wrist twist.
- Neck: Neck twist, Neck side-bending.
- Trunk: Trunk twist. Trunk side-bending.
For each of the parameters, you have a choice of three
options: Auto, Yes, and No.
Auto: |
(No or Yes): RULA is using the parameters defined in the RULA
Parameters field in Preferences. This determines the state of a specific
segment, that is, Shoulder in elevation or not,
Arm in abduction or not. |
Yes: |
By selecting Yes, you force RULA to consider the segment is at the
specified state (elevation, abduction, and others)
independent on the posture of the selected
manikin. |
No: |
By selecting No, you force RULA to consider the segment is not at
the specified state (elevation, abduction, and
others) independent on the posture of the selected
manikin. |
These intermediate scores, represented by a number and a
color, uses to calculate the final RULA score. The following
table indicates the score range for each segment as well as
the associated color.
Segment |
Score Range |
Color associated with the score |
1 |
2 |
3 |
4 |
5 |
6 |
Upper arm |
1 to 6 |
G |
G |
Y |
Y |
R |
R |
Forearm |
1 to 3 |
G |
Y |
R |
|
|
|
Wrist |
1 to 4 |
G |
Y |
O |
|
|
|
Wrist twist |
1 to 2 |
G |
R |
|
|
|
|
Neck |
1 to 6 |
G |
G |
Y |
Y |
R |
R |
Trunk |
1 to 6 |
G |
G |
Y |
Y |
R |
R |
G= Green
Y=Yellow
R=Red
O=Orange
For viewing the RULA Colors on the manikin, see the Profiles
node. See Segment Coloring Concepts.