Once in motion each body part is light and agile; they are intricately linked.

 

Highlighting right from the start  how fine grained and sensitive is the TaiJiQuan practice

 

Being light and agile on each point of the body requires a great deal of conscious work. About lightness, Yi allows us to feel our hardness and heaviness (sensitive system), in order to correct our state to lightness (motor system). Agility is also directly relying on refining our motor capacities and improving the speed of nerve impulse (notably by reinforcing the myelin sheath as signal is repeated). About linking all the body parts together, this state includes common ideas concerning structural links (tissues/muscles, posture), but above all, neuronal connections to create inside the brain between motor neurons for instance (brain plasticity). This allows us to carefully synchronize the movement. Yi truly allows harmonizing the Qi.