Biomechanics Single Action Analysis

This procedure describes how to use the Biomechanics Single Action Analysis command.
This ergonomic tool measures biomechanical data on a worker in a given pose. From the current manikin posture, the Single Action Analysis tool calculates and outputs information such as the lumbar spinal loads (abdominal force, abdominal pressure, body movements) and the forces and moments on manikin joints. All the output incorporated in the model are based on research results and algorithms published by the scientific community.

The forces (loads) acting on the manikin's hands are taken into account in the biomechanical analysis; these forces represent the load of carry, push, lift/lower, or pull, depending on the scenario, and are available for the hands only. Both the Load Properties and the Biomechanics Single Action Analysis dialog boxes can be open at the same time. The last analysis is updated when the load is modified.

  1. In the Ergonomics Tools toolbar, select the Biomechanics Single Action Analysis.

  2. In the PPR tree or the 3D view, select a manikin for the analysis.

  3. The Biomechanics Single Action Analysis dialog box for that manikin appears, opening to the default Summary tab.
     
    Summary tab The Summary tab gives general biomechanics information such as:
    • L4-L5 Moment
    • L4-L5 Compression
    • L4-L5 Joint Shear
    • Abdominal Force and Pressure
    • Ground Reaction


     
      L4-L5 Spine Limit tab The L4-L5 Spine Limit tab displays the evaluation of the posture and whether it exceeds the compression and joint shear limits recommended by NIOSH and the University of Waterloo. The information on this tab can be viewed as a list or as a chart.


     
      Joint Moment Strength Data tab

    The Joint Moment Strength Data tab displays the evaluation of the percentage of a worker population that doesn't have the strength to perform a task based on strength studies such as those by Askew, An, Morrey and Chao (1987) for the elbow, Koski and McGill (1994) for the shoulder, and Troup and Chapman (1969) for the lumbar.

    This information can be displayed as a chart or as a list.

    For a more complete analysis of the human biomechanics Results a new analysis will cover both wrists in flexion-extension and Radial-Ulnar deviation


     
      Reaction Forces and Moments tab

    The Reaction Forces and Moments displays, in detail, the reaction forces (N) and orthopedic moments (Nm) proximal and distal segments.

    This tab specifically presents many data for each analyzed segments which leads to a wide and long list that need to be so extended that the manikin is hidden.  Moreover, having to read through many lines and columns of data can introduce misread errors. A better way to display the results in 3D, each segment results are highlighted in the list when the related segment in the 3D model is selected.

    At a segment’s selection directly from the manikin, the results panel will update in order to highlight the selected segment.

    The results for a given segment can be highlighted in the Reaction Forces and Moments tab by a single selection of it either by a direct selection on the manikin or a segment node selection from the tree.

    If the segment is not part of the Biomechanics Analysis, no highlighted data will be displayed.

     
      Segment Positions tab The Segment Positions tab displays information (position, angle, center of gravity, length) about the segments.

     
      Export Results Use the Export... button to save the biomechanical data in a text file. In the Export results dialog box, select the type of information you want to save and OK.

    The biomechanical data is saved as a text file.