Ushiro goshi video
Info about "Ushiro goshi video"
Ushiro goshi (back hip), is one of the original 40 throws of Judo as developed by Jigoro Kano. It belongs to the fifth group, Gokyo, of the traditional throwing list, Gokyo-no-Nagewaza, of Kodokan Judo. It is also part of the current 67 Throws of Kodokan Judo. It is classified as a hip throwing technique, Koshi-Waza.
Ushiro Goshi is also one of the 20 techniques in Danzan Ryu’s Nagete list. 
Ushiro goshi is usually performed as a counter technique. To perform this from a stationary position, you need to be behind uke, and use your hips to lift your partner into the air then direct them to the floor with your hands.
If the knee is used to lift, the technique is not considered a ushiro goshi, some would call this o soto gaeshi due to it’s use against o soto gari. 
From Wikipedia  and Akitas Judo