Seigo Okamoto

Sensei Okamoto Intro to Daitoryu

The application of Aiki in the techniques demonstrated by Seigo Okamoto in the following video is analysed below.

Analysis

Both Uke and Tori are kneeling. Uke comes to grab Tori's wrist(s). Just before Uke grabs Tori's wrist(s), Tori changes the angle of the wrists inducing Uke to follow the wrists by reversing the muscle torque about his knee joints. Consequently, Uke is unbalanced to the front due to the muscle torque about his knee joints being in the opposite direction to that required to slow his forward momentum. Aiki-Feint

Maboroshi no Kamiwaza Daito Ryu

The application of Aiki in the techniques demonstrated by Seigo Okamoto in the following video is analysed below.

Analysis

At the time 3.27 both Uke and Tori are standing. Tori advances his wrist(s) towards Uke so that Uke grasps Tori's wrist(s) earlier than expected (Uke's forward leg is still moving forwards) inducing Uke to relax his upper body. Tori uses this opportunity to induce Uke to apply Aiki by lowering his wrists/weight inducing Uke to extend his front leg upwards as he is pulled to the front. Consequently, Uke is unbalanced to the front by the muscle torque about Uke’s front foot joint being in the opposite direction to that required to resist Tori’s pull. Aiki-Lead

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. Aiki-Feint

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. Aiki-Lead

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 momentarily relax their upper bodies as they extend their legs in preparation 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 resist Tori moving to the rear, causing both Ukes to become unbalanced to the rear. Aiki-Lead

Analysis

At a time of 27.47 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 weight onto the jo causing Uke to momentarily relax his upper body while he prepares his lower body to pull upwards on the jo by extending his legs. The action of pulling upwards causes the muscle torque about Uke's foot joints to be in the reverse direction to that required to resist Tori moving the jo to the side, causing Uke to become unbalanced to the side. Aiki-Lead

Analysis

At a time of 26.42 Uke advances to make contact with Tori's shoulder. Tori induces Uke to apply Aiki by first moving his body/shoulder upwards and then rotating his shoulder to the rear and downwards. Tori's upward movement induces Uke to momentarily relax his upper body and to prepare his lower body to push downwards. Consequently, the muscle torque about Uke's ankle joints, due to him pushing downwards, are in the opposite direction to that required to resist Tori moving his shoulder to the rear. Uke is unbalanced to the front. Aiki-Lead

Analysis

At a time of 2.47, Uke advances to make contact with Tori's hand. Tori induces Uke to apply Aiki by moving his finger/hand towards Uke so that Uke grasps Tori's finger just before Uke places his front foot on the ground and then moves his finger away from Uke. When Uke grasps Tori's finger prematurely, Uke momentarily relaxes his upper body in order to adjust the muscle torques about joints in his front leg in preparation to resist Tori's hand movements. In this relaxed state, Tori can control Uke's lower body movements by moving his finger away from Uke and induce Uke to reverse the muscle torque about the joints in his front leg so that he is easily unbalanced/thrown. Aiki-Lead

Analysis

At a time of 0.27, Uke comes to grab Tori's wrists. As Uke's hands are about to make contact, Tori lowers his wrists. This action induces Uke to apply Aiki by reversing the muscle torque about his knee joints so as to follow Tori's wrists, as they move away from him. Consequently, Uke is unbalanced to the front by his forward momentum. Aiki-Feint

At 0.43/0.49 the same method of applying Aiki is employed to unbalance the line of Ukes. Here the muscle torque about the foot joint of Uke's front foot is reversed as Tori withdraws his wrists. Aiki-Feint