Alias · Top Positions
Head and arm pin bottom
Also known as Kata Gatame — Bottom — the canonical term used on this site.
Training background: descriptive
Descriptive — defending the head-and-arm pin
Head and arm pin bottom is a descriptive name for the kata gatame bottom position — naming the defence against the head-and-arm pin and choke.
Etymology. “Head and arm” translates kata gatame’s control of the head together with one arm; “pin bottom” frames the defending side. The label describes the position from underneath in plain English.
Mechanics. The arm triangle strangles by compressing both sides of the neck — the trapped arm on one side, the shoulder on the other; the defence keeps one side uncompressed, posturing the shoulder or freeing the arm so both sides cannot close at once, since a strangle needs simultaneous pressure on both to work.
Cross-reference. “Arm triangle defence from bottom” and “Under the shoulder choke” are sibling aliases. Full mechanical coverage on Kata Gatame — Bottom.