Hi. What does these lines do in the main KneeLoad model:

BodyModel.Right.Leg.Jnt.Knee = {
  Ref = -1;

Hello Saeed,

that’s a good question since the reference manual is not clear about this. Actually since there are only two valid values (0 and 1), every value different than 0 should have the same effect as 1 which is setting joint to the second specified reference frame to be used for measuring.

I hope that covers your question.

Best regards

Actually, Ref = -1 means that reactions are measured in the global reference frame. Usually, for knees, I prefer the tibial reference frame because the tibial plateau offers a natural perpendicular and two tangential directions.