1. Inverse Dynamics and Joint Power Analysis
Visual3D
Inverse Dynamics and
Joint Power Analysis

2. Biomechanics Laboratory, School of Human Kinetics
Marker and Force Data
marker data come in a .C3D file created by Vicon, Motion Analysis, Qualysis or similar motion capture system
SIMI and APAS may also be used but data must be placed in a ASCII (.FSV) file by, for example, BioProc2/3
force data come with the .C3D file but may also be collected and placed in an ASCII (.FSV) file by BioProc2/3
data may be streamed directly to Visual3D using newest version of Visual3D and compatible motion capture system, e.g., Nexus
Biomechanics Laboratory, School of Human Kinetics

3. Biomechanics Laboratory, School of Human Kinetics
Creating the Model
first a static trial is loaded to create the model (you can use a movement trial)
a previous model may be used for a similar marker set
model is customized for each participant (mass and height etc.)
ideally markers are located at each joint but these markers do not have to be included in the movement (dynamic) trials
should save the model file (.MDH) separately for use with other trials or experimental conditions of the same person
new models must be created for each new marker set
modeling is done using graphical user interface (GUI)
Biomechanics Laboratory, School of Human Kinetics

4. Biomechanics Laboratory, School of Human Kinetics
Model Building Screen
create segments
create landmarks
enter body mass and height
Biomechanics Laboratory, School of Human Kinetics

5. Biomechanics Laboratory, School of Human Kinetics
Movement Trials
one or more movement trials may be loaded into same workspace (.CMO), essential if trials are to be averaged
model is applied to each trial
trial may be viewed with bones or geometrical solids for each segment
ground reaction forces should be checked
errors in force platform locations and parameters may be checked and changed in necessary
Biomechanics Laboratory, School of Human Kinetics

6. Biomechanics Laboratory, School of Human Kinetics
Workspace Screen
static trials
movement trials
tags to identify experimental conditions
Biomechanics Laboratory, School of Human Kinetics

7. Biomechanics Laboratory, School of Human Kinetics
Event Labeling
if events were not created by motion capture software they can be added automatically (via a pipeline) or manually with Visual3D
special events used for reports can also be added
e.g., Begin, End, Impact
events may be checked for
accuracy using GUI
Biomechanics Laboratory, School of Human Kinetics

8. Signal and Event Processing Screen
signals and events tab
edit events
signal tree
body at current event
signal histories with events marked
Biomechanics Laboratory, School of Human Kinetics

9. Data Processing Pipeline
a pipeline may be applied to process the data for inverse dynamics, energy or moment power analyses
a script may be used to perform these operations
a typical script (.V3S) includes interpolation and data filtering
special forces may be added such as moving force platforms or pedal forces
Biomechanics Laboratory, School of Human Kinetics

10. Biomechanics Laboratory, School of Human Kinetics
Pipeline Form
• commands • pipeline • options • import signals • load/save scripts
Biomechanics Laboratory, School of Human Kinetics

11. Biomechanics Laboratory, School of Human Kinetics
Graphical Reports
reports including graphs of the various kinematics and kinetics are created last
special filters may be used to display only certain types of trials, e.g., right vs. left leg starts, barefoot vs. shod gait, loaded vs. unloaded lifts
these categories are created in the workspace area
basic reports (.RGT) may be loaded or created and saved for later repeated use graphs may be exported for presentation
Biomechanics Laboratory, School of Human Kinetics

12. Biomechanics Laboratory, School of Human Kinetics
Reporting Screen
contents of pages
report pages
graphical or tabular reports
Biomechanics Laboratory, School of Human Kinetics

13. Export Data to MatLab or BioProc3
kinematic or kinetic data may be exported in .C3D or ASCII files
BioProc3 has capability of computing total, internal and external work, angular impulses and work done by individual bursts of power
script is used to create ASCII file for BioProc3
MatLab can compute foot clearance
Biomechanics Laboratory, School of Human Kinetics

14. BioProc3: External/Internal/Total Work
external work
internal work
total work
Biomechanics Laboratory, School of Human Kinetics

15. BioProc3: Work Done in Bursts
which moment of force
peak power
peak moment
mean power
total work done
Biomechanics Laboratory, School of Human Kinetics