How can I solve the RRA error? - model goes up and down after rra.

[Jeuhee Lee]

Hello. I use opensim 4.4, and I have an issue about using RRA.

I use experimental data (.C3d file) and it exports to .trc /.mot using 'matlab tool' or 'c3dtools.com'.

It works IK and ID, CMC normally. But if I input the data to RRA, the model walks up and down not straight.

I think I correctly input GRF data and confirm by 'Preview experimental Data' .



I used gait2392 model, gait2392_RRA_Tasks and gait2392_RRA_Actuators file.

Have someone ever solved this problem? advice please.

[Carmichael Ong]

Some suggestions can be found in the Simulation with OpenSim - Best Practices documentation page.

One of the tutorials also helps users learn about how RRA works: The Strength of Simulation: Estimating Leg Muscle Forces in Stance and Swing

You could also consider looking into AddBiomechanics to help with scaling and adjusting the model. Paper and Web App.