Hello
I can’t figure out why this is happening. I have a pin mesh model that connects my vertical lamp stem to the main lamp arm. I have the armature bones running through the middle of the stem, pin, and then lamp arm but when I rotate the Arm bone (in pose mode) it skews/deforms the mesh.
It seems all downstream meshes become distorted when rotating higher up bones. I have the DEFORM option for the bones turned off. Below is a picture of before and after… Any help would be appreciated!!!
Rendered View to help visualize what I see 
Thanks
Geoff