A very brief tutorial on setting up a gait cycle using the CMC tool, including adding a custom path actuator.

1. OpenSim 3.3
A Brief Tutorial

2. Scenarios 1&2
Scenario 1
• Gait 2392 model
• No actuators added
• Subject01-kinematics
Scenario 2
• Gait 2392 model
• 2 actuators added behind the
knees between calf and
hamstring
• Subject01-kinematics

3. Scenario 2-marker adjustment
• Step 1: Find gait2392.osim in files directory
• Step2: Make a new copy of file called gait2392-subject02
• Step 3: Open using notepad ++
• Step 4: minimise submenus using alt+(submenu number)
• Step 5: Locate marker set submenu
• Step 6: Open both left toe tip and right toe tip.
• Step 7: Correct marker position for incorrect marker

5. Scenario 2-add probeset
• Step 1: Open probe submenu from the same model in notepad
• Step 2: Copy probset script section from gait2392_simbody-subject-
09-timecontrol.osim model file.
• Step 3: Paste into probe submenu in current .osim file.

6. Scenario 2-add Actuator
• Step 1: Open force submenu from the same model .osim file in
notepad
• Step 2: Insert following code as a new force path actuator
• Step2.5: Or alternatively copy the acuator set from
gait2392_simbody-subject-09-timecontrol :P

9. 2-add probeset
• Note: You can check individual bone axis in the model by right clicking
on a bone in the navigation panel on the left and clicking display axis.

10. Scenario – 2 – Adding metabolics to CMC
• Step 1: Open the file called “subject09_Setup_CMC”
• Step 2: Navigate down to the following

13. Scenario 1-Inverse Kinematics
• Step 1: Open Inverse Kinematics from the tools menu
• Step 2: Load the file from the gate2392 directory "Subject 01 IK
setup"

15. Scenario 1-Inverse Kinematics
• Step 3: Check inputs and ammend any mistakes. If ammendments are
made then save the file before running. Make sure output motion is
named appropiately (subject02)
• Step 4: Run the IK computation

16. Scenario RRA
• Step 1: Open Reduce Residuals from the tools menu
• Step 2: Load the file from the gate2392 directory
"subject01_Setup_RRA“
• Step 3: Ammend Details to current subject02.osim file you are
working on.change the following.
• Desired kinematics- change to inverse kinematics ouptut file
• Change name of adjust model name to anything suitable (subject02....)
• Output file prefix and directory change to som ething useful.
• Tick external loads
• Edit the external load file to the following:

17. Your IK motion file

18. External force 1

19. External force 2

20. This will produce….

22. Scenario 2 - CMC
• Step 1: Rename the output model from the RRA accordingly by right
clicking the model in the navigation pane.
• Step 2: Open the Computed Muscle Control in the tools menu.
• Step 3: Load “subject01_Setup_CMC”
• Step 4: Change the following to the appropriate files for your simulations
so far:
• Tick filter kinematics
• Make sure actuators is set to “Append to model’s force set”
• Make sure external loads is ticked and that you load the external loads file from the
RRA simulation. Check the file contents making sure filter kinematics is ticked.
• Change kinematics file to RRA output motion file.

23. Scenario 2 - CMC
• Step 5: make sure the setup looks roughly like this:

24. Scenario 2 - CMC
• Step 6: Save and then run the simulation!

25. Scenario 2 - Outputs
• Files from the simulations are output into the specified directory
during the tool setup.
• You can open any of these files in notepad ++
• To make graphs use either:
• In Opensim – tools -> Plot
• Excel
• Excel is recommended as control over the graphs is much better
although a plot in opensim shows a line which moves when the
animation is played, showing the stage of the gait cycle.

26. Plots
• Step 1: Open plot in tools
• Step 2: click Y quantity then
select the file you want to
analyse e.g. actuation force for
subject 2
• Step 3: Tick the actuators you
want to view on the graph
• Step 4: Select x quantity and
select time.
• Step 5: Click add.

27. Voalá!

28. Just use Excel ;)