Ushiro Kesa Gatame is a mat hold often used as a transition from Kami Shiho Gatame (illustration on left).  In order to get in to this hold, tori and uki should begin in Kami Shiho Gatame.  On uki’s right side, tori grabs deeply under the uki’s right arm and locks it in by grabbing gi.  If possible, left hand should be placed under uki’s shoulder and grabs his belt.  At the same time tori, in one swift movement, brings his legs from tightly positioned by uki’s neck in to a hurdler’s stretch position.  Left leg is straight out and right leg is back with knee bent, (see illustration).    This base creates tremendous leverage.  This of course can be done on  either side of uki’s body, in reverse.  Tori can lean back on to uki’s face to cause discomfort.  As with all mat holds, this one must be very tight if it is to be effective.