posture velocity

Hi Sir
There are a posture velocity folder in the mannequin file. The values for all are set to be zero automatically in standard standing model. I want to know that what is the criteria to change them as there are many laws for scaling but i did not saw any law for changing these posture velocity values. One question more that is set i have to edit posture first before edit these values.
Thanks.
Regards
Mohit

Dear Mohit,

There is NO criteria about the change of those velocities for joint angles.

It depends on which types of motion that you would like to analyze.

Best regards,
Moonki

Hi Sir
Thanks for your reply.Sir i want to compute muscles forces on femur mesh during walking.But i have no C3D file Or Gait data.So sir could i change the standing model to walking model without these files. Sir if i apply these joint velocities then what will be the change in the posture or motion of standing model.Kindly suggest me the right approach for that.
Thanks.
Regards,
Mohit.

Dear Mohit,

It will be ‘theoretically’ possible to synthesize a walking motion using some of kinematic drivers without using any kind of motion capture data such as C3D files.

But it will NOT be possible to synthesize such a motion only by using constant velocities in the Mannequin.any file.

I would recommend you to try your best efforts to get any kind of source for gait trials instead.

For instance, you can find this kind of data here:
https://www.c3d.org/sampledata.html

Best regards,
Moonki

Hi Sir
There is a Mocap model in the anybody directory derived from C3d file. Could it be beneficial for me to do fea analysis femur bone during walking. I want to export loads in different instances during walking. But to change posture according to walking postures seems quite difficult by manually editing posture values.I have done femur analysis in standing model. Sir now i am confused in methodology for fea analysis of femur bone during walking.Some question is arising in my mind that could i have to construct different fe model for different instances or walking simulation is possible in one step.Sir please suggest me the right methodology for that and also some research papers which can help me.
Thanks.
Regards
Mohit

Hi Mohit,

Yes, you can use that one, but you would need to use the geometries present in the model to do your FEA. Otherwise the bone geometries, muscle attachments, and motion will not be consistent.

The difference in this case will be that your amplitudes (*AMPLITUDE) will not have a single value, but they will be actual curves.

There is a list of papers on our website - please check.

Regards,
Pavel

Sir i know that to use mocap model i have to scale the femur according to its geometry .Sir when i run the sequence of motion it go very slow then i pause it at particular posture(pic attached) at which i have to export the loads. Is now i have to done the codings in mocap model for loads export at particular posture as i done earlier?
Thanks.

Mohit,

You can change time of your simulation or C3D frame numbers, and do exactly like you did before.

But morphing the femur will require you to have a corresponding C3D file (the motion will be different) - think about that.

Regards,
Pavel

Ok Sir
Sir mocap model is doing a walking activity in three steps.So if i dont want the instances as i discussed earlier.Then i want to do scaling. After it i run the all sequence.So could i export the loads for that activity.
Sir my main problem is that i did not know how to define activity. How can i assign the walking activity to standing mode? In Mocap model model is doing activity of walking. My main concern is FEA IN Walking activity.In some research papers i found that researchers is doing fea at different gait instances.Is it possible to use the mocap model as i used standing model earlier for exporting loads without use gait instances?
Thanks.

Mohit,

Please revisit the tutorials, where we explain how to drive your models. You can prescribe joint angles in the mannequin file to get a posture that you want. But you could also benefit in accuracy by using the MoCap model, velocities, ground reaction forces, and limiting your simulation to the exact part that you want. The problem will be to achieve a corresponding FEA model.

To get the exact moment in the MoCap simulation you can optimize the motion for the whole trial, but for the inverse dynamics analysis you need to select tStart and tEnd that correspond to the posture that you want.

Regards,
Pavel