Alias · Triangle system
Trapped arm triangle
Also known as Trapped Triangle — the canonical term used on this site.
Training background: descriptive
Descriptive — triangle with the arm trapped in
Trapped arm triangle is a descriptive name for the trapped triangle — naming the triangle by the opponent’s arm trapped inside the legs.
Etymology. “Trapped arm” describes the arm caught inside the triangle with the head; “triangle” names the strangle. The label foregrounds the trapped limb that the strangle uses as one side of the compression.
Mechanics. The triangle isolates the trapped arm, removing it from the defensive system: caught inside the legs, the arm can no longer frame or posture, and it doubles as the structure pressing one carotid while the legs press the other. Keeping the arm trapped is what both disables the defence and completes the strangle.
Cross-reference. “Scramble triangle” is a sibling alias. Full mechanical coverage on Trapped Triangle.