Jackknife
From wipipedia.org

A jackknife tie is a bondage position in which the body is held bent in half like a jackknife. To achieve this, the legs are tied together at the knees and ankles, the wrists are tied together and then the captive bends at the waist and has the wrists and ankles fastened together.
Unlike a hogtie, the bottom is left completely accessible for spanking or other treatment.