INVERTED ARMBAR (HELICOPTER ARMBAR)

The inverted armbar (also called the helicopter armbar) is the variation of the armbar in which the attacker uses inverted body geometry to attack the opponent's arm from beneath rather than from above. The technique attacks the same elbow joint as conventional juji-gatame but with the rotational geometry inverted — the attacker rolls onto their shoulders and rotates underneath the opponent's body to produce the finishing extension.

The mechanics begin from closed guard or spider guard with the attacker isolating one of the opponent's arms via grip control. The attacker rolls onto the shoulders and inverts the body, rotating underneath the opponent while maintaining wrist control on the captured arm. The 'helicopter' name describes the rotational motion — the attacker's body rotates around like helicopter blades during the entry. The finish comes when the inversion completes and the captured arm extends fully, producing the elbow hyperextension force.

The inverted armbar has been used by various flexible-style competitors and is most associated with the modern lightweight competitive scene. Notable practitioners include the Miyao brothers and various inverted-guard specialists. The technique is rare because the entry requires substantial hip mobility and the opponent must permit the inversion to develop. Defensively the inverted armbar is escaped by hand-fighting the wrist grip before the inversion initiates, by stacking the inverted attacker to disrupt the rotation, or by tucking the captured arm to deny the extension.