Ragdoll problem with animations

Hello everyone. I made model of human with makehuman and all animations using its rig. Then I exported all as fbx to Unity. The armature is quite complex and messed up in Unity. some bones are duplicated with different weights, so I decided to create "Wrapper" skeleton what copy positions and rotations of all groups of bones of initial armature. It works nice, I can use custom IK scripts and everything seem to work.
Now I want to make ragdoll for my custom armature. I made T-Pose animation and made ragdoll in Unity in automatic mode. If I click play it works nice. But when I changed animation from T-Post to Sit on a chair one, switched armature to ragdollmode (disabled animator, enabled rigidbodies) it starts to act like on a screenshot. Everything works the same (I mean nice), except for legs. I tried to change Character joint options, collider but with no results.