Kata otoshi (shoulder drop) is a dojo favourite technique for dealing with dynamic ushiro (bear hug) attacks.  The technique is relatively simple to apply mechanically as in essence it involves the nage dropping to one knee and placing either their fist or hand on the ground.  Relaxed execution and timing are also important.

In the below video, seniors from our dojo can be seen practising the ushiro kata otoshi in its ryutai (free flowing) form.