Palm heel - Teisho

Red circle indicates striking surface

Overview
An extremely powerful technique that has advantages over a punch.

Compare to: Straight punch, Bear hand

Used in these katas
Saifa, Bassai Dai, Seiunchin, Empi, Sepai, Hangetsu, (?), Karurunfa

(Kata with a ? are open to interpretation)

Striking targets
Any part of the body

Technique
Open the hand. Tuck the thumb tightly to the side. Bend the wrist back. Strike with the pad of flesh at the base of the hand. Can be delivered in a straight line like a punch, or in an an arc like a haito

Strengths

Can be delivered to soft or bony parts of the body with equal power

Can be delivered in a straight line from an outside angle

Does not require a straight wrist, so is easier to deliver safely

Weaknesses

The fingers are weak, and must be kept out of the way