Contact Spheres on bone segments or muscles segments

[Krishnakumar Sankar]

Hi
I wanted to calculate the joint moments and muscle moments for a ball grasp activity using wrist model.I created a contact sphere covering the ball.And also contact spheres on the segments of the fingers Proximal phalanx and distal phalanx.I did this to calculate the moments generated while the contact spheres of the finger segments come in contact with the contact sphere i created enclosing the ball exactly.

I have a couple of questions here

1.Since I created contact spheres on the finger segments by hiding the muscles ,will I get only proper joint moment results and not muscle moments results ?

2.Should I create contact spheres on the muscle segments or method on point 1 is itself ok ?.


Any comments regarding this method on the first paragraph or the two points following the first two paragraphs would be of great help?

[jimmy d]

1.Since I created contact spheres on the finger segments by hiding the muscles ,will I get only proper joint moment results and not muscle moments results ?

Hiding the muscles only drops them from being displayed on the screen. It doesn't take them out of the model.

2.Should I create contact spheres on the muscle segments or method on point 1 is itself ok ?.

You can't put contact spheres on muscles, only on bodies.

[Krishnakumar Sankar]

Thank you sir.

I get joint moment and muscle moment results well but my static optimization undergoes some constraint violation.That doesnt affect joint moment and muscle moments results right ?

[Thomas Uchida]

I get joint moment and muscle moment results well but my static optimization undergoes some constraint violation.That doesnt affect joint moment and muscle moments results right ?

That conclusion may be incorrect. Constraint violations are discussed on the "Getting Started with Static Optimization" page (http://simtk-confluence.stanford.edu:80 ... timization), in the "Best Practices and Troubleshooting" section, under the "Troubleshooting" heading, item 2.