Seigo Okamoto

Sensei Okamoto  

The application of Aiki in the techniques demonstrated by Seigo Okamoto in the following videos are analysed below.

Sensei Okamoto Intro to Daitoryu


Analysis

Both Uke and Tori are kneeling. Just before Uke grabs Tori's wrist(s), Tori advances his wrist(s) towards Uke so that Uke grabs Tori's wrist(s) earlier than expected. Consequently, at the moment that Uke grabs Tori's wrist, Uke's upper legs are still rotating forwards about their knee joints. Uke is therefore unbalanced, using Aiki, by the muscle torque about the knee joint being in the reverse direction to that required to balance the contact reaction force that is pulling Uke forward due to him grabbing Tori's wrist(s). 

Maboroshi no Kamiwaza Daito Ryu 


Analysis

Between the times 3.27 to 9.55 both Uke and Tori are standing. The same method of applying Aiki, as in the first video, is used to unbalance Uke. In this case, Tori advances his wrist(s) towards Uke so that when Uke grasps Tori's wrist(s), earlier than expected, Uke's forward leg is still rotating forwards about the ankle joint.  When Uke grabs Tori's wrist(s), the contact reaction force created pulls Uke forward. This pulling force is not balanced by the muscle torque about the front foot ankle joint as the muscle torque is in the reverse direction, rotating the front leg forwards about the ankle joint. Uke is therefore unbalanced using Aiki.


Analysis

At a time of 25.57, Uke comes to push Tori's shoulders. As Uke's hands make contact with Tori's shoulders, Tori withdraws his shoulders. This action induces Uke to apply Aiki by reversing the muscle torque about his front foot ankle joint so as to follow Tori's shoulders, as they move away from him. Consequently, Uke is unbalanced to the front by his forward momentum. 


Analysis

At a time of 26.08, Uke comes to push Tori's shoulders. In this case Tori steps towards Uke and rotates his shoulders forwards to bend Uke's fingers/wrists backwards.This action induces Uke to apply Aiki by reversing the muscle torque about his rear leg knee joint so as to reduce the pressure on his fingers/wrists. Consequently, Uke is unbalanced to the rear by the contact reaction force he experiences due to him pushing against Tori's shoulders. 


Analysis

At a time of 28.30 both Ukes hold Tori's arms. Tori induces the Ukes to apply Aiki by Tori lowering his body causing the Ukes to pull upwards. The action of pulling upwards causes the muscle torque about the ankle joints to be in the reverse direction to that required to balance the pushing reaction force due to Tori moving to the rear, causing both Ukes to become unbalanced to the rear.

Analysis

At a time of 27.27 Uke thrusts a jo towards Tori's abdomen. Tori side steps the thrust and lightly catches the jo. Tori induces Uke to apply Aiki by Tori lowering his body onto the jo causing Uke to pull upwards on the jo. The action of pulling upwards causes the muscle torque about the ankle joints to be in the reverse direction to that required to balance the pulling reaction force due to Tori moving the jo to the side, causing Uke to become unbalanced to the side.