From nose to abdomen, the breathing should go down in the tree part …
Do the form with the lower abdomen as the root
With the lower abdomen as the driving force
See how the abdomen is moving when leading the form.
Chi and force separated, how is it ? The abdomen force lead all …
The abdomen muscles must be good, see how they should be able to work.
Is your lower abdomen nervous? See some test
If the abdomen is tight inside than the interior space is not moving, there is no opening and closing.