Ground path (Jin) enables us to draw on the infinite power of the earth. Only through good structure (aikibody) can be do this as well as to augment it through the tempory storage and release of it.
Effective use of ground power to topple (throw or pin) is the goal. This has been looked at where ule is considered as a single unit block in the first instance. However it is imperfect in its simplicity.
Throwing then is a battle of ground path between to partners. The goal of aiki is to join the ground path from the gorund reaction force to our extended limb and then to make aiki (through grounding, winding, reeling, piping etc…) with our partner and extend the ground path into them segment by segment.
The diagramme shows the ground path (in blue) which extends to the point of contact(dotted blue) The ground path (in green ) is connected at each segment (O) to the point of contact, then segmentally it is extended into Uke segment by segment ((i)- (v)) by toppling each of these joint segments.
Thus by extending Ki we truly make harmony (Aiki) with out partner is a quasi dynamic environment using the skills of Jin and Aikido body (Internal strength) to apply biomechanics (the topple) as a force minimisation process. Examples of this about through our aikido kata