Hi,

how one can convert Opensim model from 4.1 or 4.3 version to 3.3?

Thanks,
Alexandra

Hello,

is there any way to find out the length of the ligament taking in account its wrapping over the surface of the wrap object? It seems, that getLength() procedure outputs just the distance between origin and insertion points.

Best,
Alexandra

Dear all, i have 6DoF patellofemoral joint and try to make coordinates (translational and rotational) to change smoothly during prescribed motion. I add BushingForce, but it works too slow, if the parameters for rotational_damping and translational_damping are greater, than one. Besides, the obtaine...

Patella movement during knee flexion is considered. Patellofemoral joint has 5DoF, there are no controllers. Even if rotation angle of patella around femur is a prescribed function of time (which is linear), there still occurs a jump in this function (see attachment) after FD and in patella's transl...

Hello,

what can cause sudden jumps of translational coordinate (one of DoF in the model), computed by Forward Dynamics tool?

Are there any constraints to be set to make this function smooth?

Regards,
Alexandra

Hi,

how one can get rid of bodies oscillations in the beginning of Forward Dynamics Tool execution?
In ~98% of time everything goes well, but in the beginning of motion some bones are just trembling.

Regards,
Alexandra

Hello,

how one can choose realistic parameter values (dissipation, static_friction, dynamic_friction, viscous_friction) for the contact of two bones (patella and femur), which is modelled using ElasticFoundationForce? Also, what is the range for these parameters?


Regards,
Alexandra

Hello,

Is there any way to add coordinate limit force using .osim file? I couldn't find any examples.

Will the results of Forward Dynamics simulation be physiological in the case of using of CoordinateLimitForce?

Alexandra

Hi Vinay, thank you for your response! Is there any way to add coordinate limit force using .osim file? I am working using GUI. Is this kind of solution actually physiological? I tried to vary some model parameters to avoid additional constraints, but couldn't obtain any reasonable result. I don't k...

Dear all, i added some DoFs to patellofemoral joint in knee model https://simtk.org/projects/kneemodel, i.e. defined additional coordinates, specified the range and defined new spatial transforms as linear function of the corresponding coordinates or as simsplines. The results of Forward Dynamics de...