For those who may not be familiar with its history, the oral tradition of Daito Ryu (from which all aiki arts are derived) states that the art was handed down through the Takeda family of the Aizu domain, where they were employed as bodyguards and palace security. The same environment that led to subtle methods of power generation and kuzushi that become codified as Aiki no Jutsu also saw the development of a sophisticated method of entangling an opponent's body to render them powerless, even if only for a moment. The question, however, is why would these techniques of structural distortion be preferred over more conventional pins and hold-downs?
Being able to access your weapon while preventing your opponent from using theirs has its own challenges, but when needing to dispose of an opponent quickly as other people's lives depend on your success, engaging in a lengthy struggle is not conducive for survival. Going back to the historical context of this art, should you be engaged in close quarters fighting with an opponent their objective is to cut you down and move on to their primary target. Given the spontaneous nature of this type of attack, very rarely will you have your weapon already drawn and so you must access it under pressure. That's a lot easier to do when the opponent is immobilized. Therefore, the objective of these pins is to place the opponent in a compromised state long enough to draw your own weapon and dispose of them before they have time to either prevent you from doing so or use their own.
With feudal systems designed for warfare, you must always assume the reason comes back to the use of weapons. As the goal of these pins is to immobilize your assailant so that your hands are free to access your weapon and dispose of them, and most practitioners learn these in unarmed training sessions, this is simply to show we have complete control of the subject. Raising one hand above the head simulates bringing a blade up for a finishing cut, and outstretching both hands is to demonstrate how securely they are locked.
So the real question is if they are too complex? After all, they do look fairly intricate. The short answer is both yes and no. If done correctly, entering into these positions should flow naturally from the conclusion of the prior technique. How quickly that happens is up to the practitioner, but fighting is like chess. You perform one technique to either bait a response or set up another. If you throw an attacker to the ground with the objective to move them into a tie-up and position yourself properly, it's not difficult to transition quickly. But also like everything else, it must be trained to a level of proficiency that doesn't require cognitive processing under duress.
Now, if you're not an 19th century palace guard in feudal Japan, what modern context makes learning these pinning techniques effective or beneficial? As a security officer, I have used several traditional pins to maintain control of a subject when breaking up fights. The application for security or law enforcement should be readily apparent, as being able to restrain someone while freeing up the hands for either handcuffs or radioing for assistance is not any different than freeing the hands to access a weapon.
One of the downfalls of all ground-fighting systems is the risk of fighting multiple attackers. There are too many videos on the internet of two people fighting on the ground, and a third party coming out of nowhere and finishing the fight with a swift kick to the head. While you can make the argument that no martial art truly prepares you to deal with multiple people at once, there are strategies and tactics that can increase your chances. Going to the ground willingly is not one of them. Likewise, you don't want to continue fighting the same people continuously. If you can take one out of the fight and restrain them while maintaining an upright position with both hands free to cover, block and strike, you are in a more advantageous position than trying to hold one down in side control.
Studying classical fighting systems comes with a certain degree of allowance for training methods and techniques that may not have a modern application. As I've said in previous articles, one can only judge the efficiency of an art by its ability to meet the needs of the context it was created for. Was it designed effectively to succeed in its purpose? After that question is answered, we can then look for ways to apply the techniques or principles to situations we find ourselves in today. While the human body hasn't physically changed, fighting certainly has. These pins and tie-ups may fill a narrow window in the context of modern civilian self defense, but if you need to buy yourself just a moment in time, they may be exactly what you're looking for.