Describing the path of nage's (defender) lead and uke flow for Ushiro Tekube/Hiji/Kata Tori Kokyu Nage. Aikido is often described in books as being all about circles. Practice tells us the most interesting things happen when uke (the attacker) enters and exits the circle. Physics tells us objects leaving a circle want to continue on a path tangent to the point of exit and vice versa for entering the circle. Don't fight physics. It is our friend.
You don't need to be a mathematician to practice Aikido, but having paid half-attention in geometry and physics classes in grade school doesn't hurt. :)
We've added a video to our YouTube Channel to help visualize this concept.
#aikido #aikidokokikai #kokikai #physics #math