Search found 48 matches

by Pia Stefanek
Wed Jul 31, 2019 6:32 am
Forum: OpenSim
Topic: Inverse Dynamics - external loads
Replies: 1
Views: 267

Inverse Dynamics - external loads

Hi, The Inverse Dynamics Tool enables the input of an external loads file including reaction forces and torques. But, isn't it correct that the acting external torques are normally just generated from the acting external forces? So do I have to include the torques for every motion or just for those ...
by Pia Stefanek
Wed Jul 17, 2019 1:36 am
Forum: OpenSim
Topic: Shoulder_WCP
Replies: 1
Views: 187

Shoulder_WCP

Hi! I downloaded the model Shoulder_WCP (https://simtk.org/projects/propulsion) to simulate shoulder kinematics and kinetics during wheelchair propulsion. When I open the model the hand is at the wrong position. Shoulder_WCP.PNG I think that the only way to get it to the right position is to change ...
by Pia Stefanek
Mon Jul 15, 2019 6:53 am
Forum: OpenSim
Topic: Upper extremity model for ID
Replies: 1
Views: 221

Upper extremity model for ID

Hi,

Is there any upper extremity model in OpenSim that was designed for Inverse Dynamics?

I already used the MoBL-Arms model and the Dynamic Arm Simulator for my studies but they yield different results and I am not sure if they are correct.

Thanks for your help!

Regards,
Pia
by Pia Stefanek
Mon Jul 08, 2019 2:33 am
Forum: OpenSim
Topic: Maximum Torque Values
Replies: 2
Views: 409

Re: Maximum Torque Values

Thank you very much for your reply! As you said I grouped the muscles into those who produce a positive and a negative moment for example for the shoulder elevation moment. My wheelchair movement simulation yielded the following result for the shoulder elevation moment: Maximum negative moment: -90 ...
by Pia Stefanek
Thu Jun 27, 2019 5:02 am
Forum: OpenSim
Topic: Maximum Torque Values
Replies: 2
Views: 409

Maximum Torque Values

Hi, I used the MoBL-Arms model to simulate a handbike movement and a wheelchair movement of the upper extremity. I used the following OpenSim tools: Scaling, Inverse Kinematics and Inverse Dynamics. Now I want to compare the computed joint Torque values to maximum joint torque values. I want to know...
by Pia Stefanek
Mon May 06, 2019 2:56 am
Forum: OpenSim
Topic: Coordinate Range - MoBL_ARMS model
Replies: 0
Views: 169

Coordinate Range - MoBL_ARMS model

Hi, Does anybody know how the range of the coordinates (maximum and minimum values of the joint angles) is selected for the MoBL ARMS model? Internal shoulder rotation is only allowed to a maximum value of 20 degrees. I found articles describing internal shoulder rotation of up to 70 or more degrees...
by Pia Stefanek
Thu Mar 14, 2019 6:47 am
Forum: OpenSim
Topic: Inverse Dynamics - Joint rotation axis
Replies: 1
Views: 267

Inverse Dynamics - Joint rotation axis

Hi, I use the MoBL ARMS model to simulate crank turn movement. I calculated the occuring torques with the Inverse Dynamics tool. Thereby, I receive the elv_angle_moment and the shoulder_elv moment. But, I would like to know the shoulder abduction/adduction and the shoulder flexion/extension torques....
by Pia Stefanek
Fri Mar 08, 2019 12:52 am
Forum: OpenSim
Topic: MoBL_ARMS - Mistake in ID
Replies: 3
Views: 1173

Re: MoBL_ARMS - Mistake in ID

Hi, 1. I found out that when I use multiplier functions in my coordinate set, the error decreases a lot. I discovered this effect by chance so maybe someone can help me to understand what the multiplier function exactly does. And why the function helps to decrease my ID error. One example of the Mul...
by Pia Stefanek
Thu Mar 07, 2019 12:34 am
Forum: OpenSim
Topic: MoBL_ARMS - Mistake in ID
Replies: 3
Views: 1173

Re: MoBL_ARMS - Mistake in ID

Thanks for your reply Ajay, I attached the model (already scaled) and the IK results to my post. Maybe you can have a look? I tried to perform IK and ID without limitation of the r_z coordinate and the results were still comparable so this cannot be the reason for the high moments. The person uses t...
by Pia Stefanek
Tue Mar 05, 2019 7:42 am
Forum: OpenSim
Topic: MoBL_ARMS - Mistake in ID
Replies: 3
Views: 1173

MoBL_ARMS - Mistake in ID

Hi, I took the MoBL_ARMS model and added a crank handle to the model. I attached a picture to the post. I limited the r_z coordinate to avoid mistakes during scaling and inverse dynamics. The IK results look correct but when I perform ID I get really high moments of more than 1000Nm. Does anybody kn...