Re: Ushiro ate-atemi waza?
A couple quick thoughts...
Tomiki's atemi-waza were not taught to me as percussive, such as the boxer's jab-hook-cross-uppercut, or the various methods of delivering shocking impact using a hand via fist-palm-knife edge-ridge edge- backknuckle, etc.
But... they "could" be, if useful at a proper use moment.
Shomenate, push-drive through the uke's week posture point, generally to the rear but not always so, right? Well, instead of the unbendable arm driving push, attacking center with center .... trade that in for the trained striker's use of a palm heel strike, with exactly the same kuzushi & tsukuri as you'd normally use. Very effective, though the jury is out if it is indeed more effective than the drive through on body drop. If you really do it, showmen is mean mojo.
The same can be done, as mentioned above, with differing strikes, sure. I'll just break down by number not name for my fellow Tomiki folks. You all know this, probably.
#2 lead hand push on elbow, but the follow hand can really come through to pop uke with any number of different strikes and locations. Kata says follow o the face, but a driving strike to the solar plexus can finish the event.
#3 is the easiest to see, knife hand to the face, though I can promise you on this one (figured the hard way, oops) that the "soft" version with spine lock is way more fierce an effect on uke than just the face smack - unless you can get both effects combined, which is harder than you might believe as they aren't "there" anymore.
#4 is the elbow, of course, and I'm sure that you could use chopping motions, palm heel strikes, double knifehand strikes, whatever, as long as the attack is generally taking uke back through the off-balance point directly behing or to a rear corner - either works, some have better success with one, some the other. I like both.