Initial Closing
Steps:
1) Create a stick from rear heel to rear kua by rotating
the rear kua to point the rear knee up and back
2) Stretch the head against the rear heel and lock the back
3) Bring in both elbows towards the line formed
between front hand and rear heel
4) Pull in the elbow through the dantian towards the
rear heel, and drag in the front foot at the same time
Source: https://practicalmethod.com/?p=48584