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plot after apply external force to model

Posted: Mon May 27, 2019 9:29 pm
by saeedaram
hello
I added an external force on tibia_r body to gait2354 model of opensim. then applied a motion (subject01_walk1_states_degree.mot) to that model. after I plotted a diagram of knee_angle_r to time for model before and after of added external force but i didnt see any change in diagram. I want to know why doesnt it change?

Re: plot after apply external force to model

Posted: Mon May 27, 2019 11:34 pm
by tkuchida
I added an external force on tibia_r body to gait2354 model of opensim. then applied a motion (subject01_walk1_states_degree.mot) to that model. after I plotted a diagram of knee_angle_r to time for model before and after of added external force but i didnt see any change in diagram. I want to know why doesnt it change?
The knee angle will not change if you are forcing the model to track the same motion as before.

Re: plot after apply external force to model

Posted: Tue May 28, 2019 12:58 am
by saeedaram
tkuchida wrote:
Mon May 27, 2019 11:34 pm
I added an external force on tibia_r body to gait2354 model of opensim. then applied a motion (subject01_walk1_states_degree.mot) to that model. after I plotted a diagram of knee_angle_r to time for model before and after of added external force but i didnt see any change in diagram. I want to know why doesnt it change?
The knee angle will not change if you are forcing the model to track the same motion as before.
thanks for your response
so what should I do if I want to plot model after applying external force to the tibia ( how can I set new motion with this external force to model )?

Re: plot after apply external force to model

Posted: Tue May 28, 2019 1:15 am
by tkuchida
so what should I do if I want to plot model after applying external force to the tibia ( how can I set new motion with this external force to model )?
Please see the "The Forward Problem" section of the "Overview of the OpenSim Workflow" page in the Confluence documentation (https://simtk-confluence.stanford.edu:8 ... m+Workflow). Some recent work in this area is described in Ong et al. (2019) Predicting gait adaptations due to ankle plantarflexor muscle weakness and contracture using physics-based musculoskeletal simulations, https://doi.org/10.1101/597294.