Am learning about bones, so created a very basic rig. When I rotate or move my foot bone, it scales that part of the mesh.
My object scaling is set to 1 ((ctrl + a) read about this from another question).
Here is a GIF showing the issue, and the weight paint for the foot. Am not sure how to fix this. I recreated my armature a number of times, but the same thing happens with the foot bones.