Hi
(I wrote this for a while ago, just posting it again, it might help you out. It took me a bit of work to nail down all the parameters for CMC and RRA)
Most (read all) of these suggestions I got from Ayman Habib, so all credit should go his way.
Its no internal ranking between the ordering, you probably have to look into all points to get a good solution and understand the RRA and CMC.
1: Read the homepage
http://wiki.simtk.org/opensim/rraCmcPage
2: Check your ground reaction force, does it align up with the correct time frame
(you can read the mot file into matlab)
3: Check again your ground reaction force, is it described correctly in the OpenSim coordinate system? Compare to the motion capture software, maybe an axis is point in the wrong direction.
4: check your model and setup files, like Actuators and Task. Have you looked or unlocked any joints in the model file? If so, you have to change these file so everything match. Like the subtalar or mtp joint.
5:Center of mass
AFTER the scaling you have to open the model file (osim) and copy the center of mass (COM) for the pelvis. This because when you scale the model the COM moves).
For RRA:
Before running the RRA you have to copy the new COM into the RRA Actuator files. (see further down for example)
For CMC / after RRA (or if you go direct from scaling to CMC)
The RRA gives you a new model file, with a new COM, so again open the file, copy the COM and past the new value into the actuator file.
(so if you run both RRA and CMC you have to do it twice)
Example:
In the osim file, in <Body name="pelvis"> you have something like this
<mass_center> -0.07357895 0.00000000 0.00000000 </mass_center>
copy these values and past them into the actuator file in the point_B node (they stand for FX, FY and FZ)
<Force name="FX">
<optimal_force> 100.00000000 </optimal_force>
<body_A> ground </body_A>
<point_A> 0.000 0.000 0.000 </point_A>
<direction_A> -1.000 0.000 0.000 </direction_A>
<body_B> pelvis </body_B>
<point_B> -0.0724376 0.00000000 0.00000000 </point_B>
</Force>
6: kp and kv parameters, if the motion is fast you might have to increase these, see the manual and homepage for equation.
7: Weights, there are plenty of them, use higher values of joints/markers you are confident in. Check your IK solution, is this what you want. Does you motion need the mtp or subtalar joint?
8: In the Actuators file, you have reserve actuators (read OpenSim users guide for more info about these) enable them, except for the joints you have locked.
The idea is that you should not need these, but sometime the model is not strong enough, and this give it some extra force, but read the manual for more info.
9: The Setup file,
read and take a look of the following parameters
maximum_number_of_integrator_steps
maximum_integrator_step_size
integrator_error_tolerance
integrator_fine_tolerance
optimizer_max_iterations
for CMC also make sure that
adjust_com_to_reduce_residuals is set to false