Chansigong : Twining silk exercises, Part 2

Chen XiaoWang uses a count of four numbers for his Single-hand and Double-hand exercises;  two of them mark the two critical points of change in the direction of Qi-flow, and other two mark the transfers of weight from leg to leg.  The Qi circuit has four focal areas en route : dantian, upper back, the hands and the sides of the torso at waist height.

Chansigong Part 1 has one Single-hand exercise (which I'll call A);  Part 2 has a further two (B and C).
In A and B, the movement outwards from back to shoulder, elbow and hand (count 'four' in the exercise) is similar;  the Qi-road in Master Chen's terminology is basically the same.
B begins to differentiate itself subtly from A when the count of 'four' changes to 'one' : you quickly realise that there is now a new sensation of twining in the arm.  Whereas in A, the arm arcs gradually and the route to dantian is simple, in B the arm coils back into itself : you feel yourself the silkworm, instinctively withdrawing/recoiling into Yin (count of 'two').
Continuing with B, the progression from count 'two' to 'three' is where the worm turns : that recoil back to dantian which is of a different impulse brings forth a new range of motion.  It is no longer the minimal undulation at the core as in the exercises of Part 1; in Chansigong Part 2,  the torsion achieved by the closer rotation of the arm in count 'one', absorbed into dantian in count 'two',  rises through the torso in a strong twisting action.  The Jing is led out in this twisting.