I must add one more point from the training purpose of Tekki Shodan. As you can see in the photo, Master Funakoshi is beautifully demonstrating the flexibility of his hips. A student must learn to rotate the upper body in 180 degrees in this particular combinations without deforming perfect kiba dachi. Unless your hips and mid section are flexible it will be extremely difficult to rotate the upper body as shown below. This the excellent example of a solid and unmovable stance with a flexible upper body movements.
