Is it possible to perform inverse dynamics analysis in OpenSim without using force plates?

[Catarina Santos]

I am conducting research on lower limb biomechanics in real-world work environments. I am using a motion capture system and lower limb EMG to collect data during standing work tasks, where the use of force plates is not feasible.
My objective is to analyze the biomechanics of the lower limbs with and without an exoskeleton using OpenSim. However, I am unsure if performing inverse dynamics analysis is possible without force plate data.

[Adrián Schmedling]

Hi Catarina,

From my experience I would say that perform inverse dynamics without GRF is not feasible for a lower limbs analysis. Maybe you could estimate the forces from the EMG measures and the weight, I have read something about that kind of process. Another longer and complicated way to do that is performing a predictive analysis (Forward dynamic) with a foot-ground contact models to estimate the forces.

[Catarina Santos]

Hi Catarina,

From my experience I would say that perform inverse dynamics without GRF is not feasible for a lower limbs analysis. Maybe you could estimate the forces from the EMG measures and the weight, I have read something about that kind of process. Another longer and complicated way to do that is performing a predictive analysis (Forward dynamic) with a foot-ground contact models to estimate the forces.

Hi Adrian,

I greatly appreciate your suggestion. Could you kindly share literature related to the process you mentioned? While I've come across some studies on similar topics, they primarily focus on walking tasks. Since I'm collecting data from surgeons who spend prolonged periods in static standing positions during procedures, those methods may not be applicable. As an example, I've reviewed this resource https://simtk-confluence.stanford.edu: ... k+Approach


Thank you for your help

[Adrián Schmedling]

Hi Catarina

I have gone through the literature I have found and as you say they all refer to walking test. In my research work I'm studying stance positions, but don't use EMG sensors and when I have tried to predict the GRF the response has been to make feet-ground contact models.

One solution that I found an maybe could work for you is to create a 2D model and assume that the loads are simetric. I this article you have an example:

https://pubmed.ncbi.nlm.nih.gov/34550877/

I hope it helps