Two objects tied together with non-linear springs

Hi all,
I have two rigid object bones tied together with lines attached to points attached to the meshes at specific points. I think I created all necessary listener parameters but I don’t seem to get independent motion, when the simulation runs, the femur falls to the ground, but the tibia floats at the same level. I’m not convinced that the lines are following either, can you let me know what you think might be incorrect in the model? Thank you.ligament physics (27.0 KB)

@DanielPiker I think you would be the person to ask, specifically, can you let me know how to best connect the two meshes by a line and points so they can move relatively? The knee is not a hinge so the lines are not necessarily rigid, maybe i can substitute the flexible rods you had given examples for so that they can rotate about the point attachments and also bend if the knee is in torsion along the long axis.

Can you post your file with the geometry internalised?

Here you go, thanks.ligament physics (2.5 MB)