results-deficits-weakness

[Samane Amini]

Hey guys

I would like to obtain the muscle forces of scone results of deficits weakness (gs-pf-so) from the following paper
"Predicting gait adaptations due to ankle plantarflexor muscle weakness and contracture using physics-based musculoskeletal simulations"
https://simtk.org/frs/?group_id=1631

to do this, I have opened the osim model and run inverse dynamic tools by entering the motion.sto from the results folder. then plot the total muscle fiberforce through Tools>Plot.

the issue is that muscle force for gastroc muscle is not displayed:

Captureeee.PNG (24.35 KiB) Viewed 965 times

Do you know how to get the muscle forces of optimization scone result?

[Thomas Geijtenbeek]

Hi Samane, this seems like a question for the OpenSim team. Please have a look at the OpenSim forum

[Samane Amini]

Hey Thomas

Ok sure. So do you think to have muscle force of scone result, I have to use only ID opensim? is there any way at scone?

[Thomas Geijtenbeek]

If you run a SCONE simulation, the muscle force (along with many other parameters) will be available -- both in the 'Analysis Window' in SCONE as well as in the .sto file that is generated automatically. Check Tools -> Preferences -> Data to select the data that is exported.

To see it in action, simply evaluate one of the .scone scenarios from the Tutorials or Examples folder.

[Samane Amini]

thank you for fast replying.

I have done it. but a strange thing is the muscle forces range is less than 1. Are the forces scaled?

forcess.PNG (200.93 KiB) Viewed 918 times

[Thomas Geijtenbeek]

Yes, these are normalized by max_isometric_force. If you want the total force (and other properties), go to Tools -> Preferences -> Data and check the box next to 'Output muscle properties'.

[Saadia Talay]

I have a similar question
If muscle forces are normalized by Max isometric forces, are the loads also normalized? Because I'm getting a back load of around 0.5 +- 0.2 for a normal gait cycle. I'm a bit confused as to what the unit is on the y axis.

[Thomas Geijtenbeek]

Loads are normalized by body weight (i.e. divided by mass * g).

[Saadia Talay]

Loads are normalized by body weight (i.e. divided by mass * g).

Thanks!