Multisurface Wrapping

I’m trying to add an external band to the human model by defining a wrapping surface between the L1 and right thigh segments. I added the gluteus maximus as a wrapping surface for the lower part of the band, however for the upper part, I’m not sure how to use erector spinae as the other surface for the rest of wrapping.
AnySurface &srf = Main.HumanModel.BodyModel.Left.Leg.Seg.Pelvis.Muscles.GlueteusMaximusWrapSurfaces.Inferior2.cyl;
I’m wondering if it’s correct. I guess what I did is like adding the band to the same surface that the gluteus maximus is attached, since this surface has been defined previously in Anybody, however for erector spinae, as no wrapping surface is defined (it’s a via point muscle), I’m not sure how I can define it.



Hi Zeinab,

It seems reasonable to use the wrapping surface that is used for gluteus maximus for your external band.

For the spine, I suppose, you will need to define new wrapping surfaces. There are different types of surfaces available in AnyBody. I would suggest you use one of the analytical surfaces (e.g., AnySurfCylinder, AnySurfEllipsoid, AnySurfSphere, AnySurfTorus) as they are computationally more efficient. The surface must be defined on some reference frame (AnyRefNode, AnySeg, etc.). You can see the reference manual for more details.

You will need to figure out the best configuration for the wrapping surfaces based on the activities you want to simulate and the attachment of the band. One idea could be to have a surface on L5 in combination with the surface for gluteus maximus to ensure the band wraps over L5 and doesn't penetrate the lumbar segments.

I hope this helps.

Best regards,