simtk.org

Hello everyone

Setting MuscleDorceDirection plugin on local coordinate system gives you constant values for muscle origin/insertion coordinates which are independent of time. Also it gives you varying muscle force directions with respect to time.

The question is, what are the location and orientation of this local coordinate system themselves??
surely they would be somewhere on the bone but where and by which orientation?

I need to adjust another coordinate system with respect to this one, in my research.

Best,
Yunus.

Hi Yunus,
apologies for only spotting this message now. As you might have guessed the forum is not monitored very often.
Local coordinate systems for the various model bodies can be visualised using the OpenSim graphical interface. You select a body, right click and check "Show Axes". Their numerical values for a given kinematics can be investigated using a BodyKinematics analysis, if I remember correctly (I haven't used it in a while), please double check in the OpenSim documentation.
Muscle attachments on these coordinate systems are indeed constant in time, while certain via points might change as a function of state (the plugin takes that into account).
I hope this helps,
Best,
Luca