The "old school karate guard"?

The third picture is of Master Seikichi Odo(FYI).

Yes. This is very typical as these are all Okinawan Masters. This technique is found in several kata of the Suidi/Shurite and Dumai/Tomarite. The closed fist represents grab-hand - tuidi/tuite. It represents grabbing an extremity and crushing, gripping flesh and attacking pressure points.

The specific arm position shows the area of attack can be an elbow and should or wrist and elbow grapple. It can also be an elbow break, if you twist the arm to face the back of it to you and hyper-extend, breaking the elbow. Also a collar bone break... many oyo from this. The manner of use shown here is as a shield.

Great pictures. It can be used as a guard, but it is not a guard.

In the real world you normally wouldn't block with both hands under most conditions. .

In our case when we do Arm conditioning (kote kitae) we do a variation of the morote-uke block but only with the one hand.

Also the links you show, setup for a back fist, which can be a great technique under the right conditions. Again, you're probably not going to do them in most cases, but if you can they can be brutal.

It is not really a 'guard', rather more likely a grapple.

Much grappling goes on in karate kata, some seem unaware of.

Darth is well versed in this area of martial art. He gave you a great answer.

These are in our kata. Like Darth and Jim pointed out these are not guards.

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