What is Fumbari in Japanese Katana terminology?

"Fumbari" (踏張り) refers to a shape where the base of the sword, known as the "Motohaba", is wide, and the width narrows dramatically as it approaches the tip, known as the "Sakihaba". This shape is often seen in "Tachi" (a type of traditionally made Japanese sword) from the Heian to Kamakura periods. The term "Fumbari" is derived from the resemblance of this shape to a person standing with their feet firmly planted and spreading out at the base, and narrowing as it goes up towards the head. This highlights the aesthetic sensibilities and practical considerations of the swordsmiths during these periods. The wide base would have provided stability and balance, while the narrow tip would have made the sword more effective for thrusting.