The essence of Chi Running is the use of the momentum of the forward fall to pull you forward rather than using the muscles in your legs and feet to push you forward.
It is important to be conscious of your center when aligning your posture and leaning it forward to create the forward fall. Your center is situated between your belly button and pubic bone where the lower abdominals and pelvis are located.
You create the forward fall by aligning your posture and leaning it forward with completely relaxed ankles. The ankles serve as the hinge point between your aligned posture whenever your feet are in contact with the ground. The forward lean moves your body weight in front of your ankles to create the forward momentum. In order to ensure relaxed ankles, you must release all tension in the lower legs (balls of foot, calves, etc.).
A common mistake made when learning to lean your posture forward, is bending at the waist. Being conscious of your center is crucial to avoid this mistake.
You must be conscious of your center to engage the lower abdominals and keep the pelvis level through the different angles of lean. The greater the angle of lean, the greater the level of effort required to maintain a level pelvis. Your lower abdominals are the only muscles in the body that you intentionally engage, all other muscles should be relaxed.
When aligning your posture imagine there is a string with one end attached to your lower abdominals and the other end running up through your chin and attached to the crown of your head. Now whenever you push up the sky with the crown of the head to lengthen your spine and straighten your neck, imagine the string also pulls up on your lower abdominals to level the pelvis. This visualization helps you to align your posture in one step and to keep you constantly aware of your center.
When you bend at the waist your center actually moves backward while your upper body moves forward. To avoid this when leaning your posture forward feel your center and just focus on moving it in front of where your feet contact the ground. This will prevent you from moving your center backwards and bending at the waist.
Be conscious of your feet and ensure they only contact the ground behind your center. Ensure the lower legs and ankles are completely relaxed at all times. Use a very short stride length and ensure your feet contact the ground with a full foot strike without any push off. Visualize you are running on a bed of hot coals and you just want to only put your foot down long enough to support your body weight then immediately lift it off.