Sentence with " plumb of heel" in it?? Footwear industry experts please!!?

Question

Hi. I am a student doing research on footwear industry terminology. I need a context for "plumb of heel" in English by an expert in this field. ( Definition: the contours of the last bottom designed to produce a shoe which will give correct surface for the foot to rest on standing and walking.) I´d be very happy if you could help me. Thanks!!

Answer 1

it refers to the ability of the heel to keep the leg/body straight