RULA Analysis

This task describes the RULA analysis procedure using the RULA Analysis dialog box.
For more information on RULA analysis, see the Analysis Introduction in the Getting Started section.

In the IK Behavior panel, the Optimize Criteria allows you to choose to optimize the posture according to either Postural Score or RULA Analysis.  This option will be in effect when IK mode or Reach mode is used, as well as when the IK solver is called to resolve a constraints update.

By default, the None button would be selected. Only one of the three options can be available at the same time.

When the Postural Score is ON, then the IK will always internally refer to the Postural Score and try to find the best score for each segment involved in the IK chain being manipulated. This would have required you to apply preferred angles to these segments, before using the optimize capability.  If no Preferred Angles are applied to the Manikin, then the Postural Score option would be grayed and made unavailable.

When RULA is selected, then the IK would use the RULA internal preferred angles calculation (that lead to a global score when RULA is used 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.

However, a Human Activity Analysis license must be present in his current configuration. If this is not the case, the option for RULA would be grayed and made unavailable.

Select the Launch RULA Analysis from the Ergonomic Tools toolbar. The RULA Analysis dialog box appears when the Manikin is selected. The dialog box has the following fields:

  • Side: Select the side of the manikin that will be analyzed.
  • Parameters - Specify settings that are not automatically set.
  • Score - Displays the score obtained by the analysis.
  • Details - Displays the details of the analysis



Side: Use the two toggle buttons to select the side of the manikin that will be analyzed.
Parameters Use the options in this zone to specify settings that cannot be set automatically.
Posture Three types of postures are predetermined:
  • Static
  • Intermittent
  • Repeated

Select the one that best describes the worker's situation.

 
Repeat Frequency This parameter is used 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 midline
  • Check 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 type a value into this field.
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) Indicates that the posture is acceptable if it is not maintained or repeated for long periods of time.

  • 3 and 4: (Yellow) Indicates that further investigation is needed and changes may be required.

  • 5 and 6: (Orange) Indicates that investigation and changes are required soon.

  • 7: (Red) Indicates that investigation and changes are required immediately.

  • Use the More button 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 are obtained by subjective values. In the basic mode, these values are automatically set to default; in the advanced mode you can change these values. The score will then be modified to reflect these new values.


Use the Less button to switch back to the basic mode.
Details The Details section that is displayed when you press the More button presents the score obtained for each section and used to calculate the final RULA score. The parameters of six of these segments can be edited:

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 (Tools->Options->Ergonomics Design & Analysis) to determine the state of a specific segment, i.e., Shoulder in elevation or not, Arm in abduction or not, etc.

Yes:

 By selecting Yes, you force RULA to consider that the segment is at the specified state (elevation, abduction, etc.) no matter what the posture of the selected manikin is.

No:

 By selecting No, you force RULA to consider that the segment is not at the specified state (elevation, abduction, etc.) no matter what the posture of the selected manikin is.

 

These intermediate scores, represented by a number and a color, are used 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 to the score
1 2 3 4 5 6
Upper arm 1 to 6            
Forearm 1 to 3            
Wrist 1 to 4            
Wrist twist 1 to 2            
Neck 1 to 6            
Trunk 1 to 6            

  For viewing the RULA Colors on the manikin, please see Segment coloring for RULA Analysis.

 

 
   
For more information on the RULA method, please read the following page that explains the steps for manually carrying the RULA evaluation.

RULA Employee Assessment Worksheet
For more information about customization, please see Customizing RULA Specifications.

For exporting the data in a report, please see Reporting Capabilities and Reporting Capabilities for RULA in XML format in Human Task Simulation workbench (this will be selectable for activation only if the proper product license check succeeds for this analysis, and the workbench is available).