Foot IK causes Character to bend knees

Hello,

I've had this issue for a while our animations exported from Blender have straight legs when in FK mode but when the IK is used in the preview window the character's pelvis rotates forward and causes the knee to bend a bit.

When the IK checkbox is used for the animation clip in the animation controller the same thing happens.

I've tried creating a correction layer in the controller which is a additive layer with a animation clip of extra rotations for the effected parts

Using Humanoid rig, but the extra animations I put on are
Animator.Left Upper Leg Front-Back
Animator.Right Upper Leg Front-Back
Animator.Left Lower Leg Stretch
Animator.Right Lower Leg Stretch

But they don't seem to effect the animation. I'm not sure what's causing it, but I also suspect it maybe that the animation is being re-targetted onto a different rig. However I have tried on the fbx creating the avatar from the animation file and the problem can still be seen in the preview window



I tried doing a search on the forums but the key words I used return no results, I think because the words are too common

Thanks

 

Did you manage to solve this problem? I could solve the problem partly with the tip in this video, but not completely. The tip is to reduce "Leg Stretch" in the rig's "Muscles & Settings" tab. Does anyone know a way to fix the problem all the way?