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Comparing experimental EMG with simulated activation from CMC

Posted: Fri Jan 17, 2020 10:57 am
by sanzid33
When we collect experimental EMG data for a gait cycle, the data is not normalized. But in the CMC and Static optimization(SO) of OpenSim, we get normalized muscle activation. If we normalize the experimental data with MVC, then will it be ideal to compare the magnitude of experimental EMG data with OpenSim (CMC/SO) simulation?

Re: Comparing experimental EMG with simulated activation from CMC

Posted: Fri Jan 17, 2020 2:21 pm
by tkuchida
There's some discussion of comparison with EMG in Section 3.5 and the Case Study on page 17 of this paper, as well as the papers it cites: Hicks JL, et al. Is my model good enough? Best practices for verification and validation of musculoskeletal models and simulations of movement. ASME Journal of Biomechanical Engineering, 137(2):020905. https://nmbl.stanford.edu/publications/ ... ks2015.pdf

Re: Comparing experimental EMG with simulated activation from CMC

Posted: Fri Jan 17, 2020 3:05 pm
by sanzid33
I have already read that paper. But, it didn't clearly say that if we normalize the experimental EMG data, we can compare the amplitude with simulation muscle activity.

Re: Comparing experimental EMG with simulated activation from CMC

Posted: Fri Jan 17, 2020 7:53 pm
by tkuchida
it didn't clearly say that if we normalize the experimental EMG data, we can compare the amplitude with simulation muscle activity
I think it depends (on the muscle, activity, electrode placement, required precision, etc.). Please see the papers that are referenced in Section 3.5. For example, Arnold et al. (2013) use normalized EMG to drive their model: "How muscle fiber lengths and velocities affect muscle force generation as humans walk and run at different speeds", https://doi.org/10.1242/jeb.075697