Problems with "LowerExtremity.any" using Helen Hayes marker set

Hi there,

I'm Dwan Lee from South-Korea.

I have two questions about my gait model.

Firstly,
I removed C7, T10 markers and turned off some drivers which related to skull, thorax joints.
Then the skull is moving down when the model is running such as an attached picture.
How can I fix it?


Secondly,
My model has only SXS(Sternum) marker in the upper body.
If I set "ON" Lumber rhythm, my model is got an error, so I keep "OFF".
My second question is if the setting still keeps "OFF", does it influence data from mine?

Thank you,

Best regards,

Dwan Lee

Hi Dwan,

When there is only one marker left on the upper body you will need extra drivers to drive the missing DOF's in the model.

I would keep driver for the neck, since there is nothing else to drive the head.

Secondly the SXS marker is not enough to drive the lumbar spine i would add at least the driver for the pelvic-thoracic rotation.

I would keep the pelvic thorax rotation.

Last thing i can see that many of the drivers are enabled like pelvic_pos etc. these should all be off since you have markers to drive these dof, these drivers may create trouble since the markers will have to violate them.

I would leave all off except neck and pelvic-thoracic rotation, and keep all rhythms both lumbar and neck.

Best regards
Søren

1 Like

Thanks, Søren

It was really helpful to me.

By the way,

I still have a problem with the skull.

It hasn't been fixed even I followed your advice.

It's still moving down when the model is running.

How can I fix the skull motion?

Do I try to insert an extra driver for it?

Best regards,

Dwan Lee

Hi Dwan,

Did you set to On the drivers for skull-thorax ?

What you see could be explained if you left these to OFF
Then there would be no drivers left for skull

Best regards
Søren

1 Like

Thanks, Søren

Finally, I fixed it!

I really appreciate your help.