Vertex Group doesn't follow bone correctly

I need he deformation of this model to be rigid, so I’m using vertex groups and having their weight be 100%. The vertex groups’ names match the names of the bones.
However when I move the bone, the mesh doesn’t follow it like it should. Observe:

Then, when I pose it:

The mesh (that rectangle you see) also shrinks a little. The size and position of the mesh should be exactly the same, and it’s rotation should exactly match the bone’s. Can anyone help me achieve that? Attached is the .blend file.


Fikou_RIGGED.blend (277 KB)

Can anyone please help?

Bone ‘right shoulder’ also has 100% weight on that leg. So the leg bones has to share with that one.

Btw, is there a purpose for ‘right shoulder’? If it’s only to connect the limbs to the torso, then you can get rid of it. Blender can do offset parenting

Wow, missed that completely. Thanks! After googling offset parenting, it looks like those “shoulder” joints weren’t necessary at all. I appreciate that tidbit! :slight_smile: