The understanding of vertical movements (line) and horizontal movements (line) is vital. Chen Style Taijiquan Practical Method system requires that all movements must be along the vertical line, not the horizontal line.
Vertical line is defined as the lengthwise line; horizontal line is defined as the widthwise line.
When this principle is followed, movements will also comply with the adage of “long overcoming short”.
http://practicalmethod.com/2013/12/horizontal-vs-vertical-online-video-trailer/
{ 2 comments… read them below or add one }
So horizontal line is moving, vertical line is not moving.
Same as rotation is also not moving.
Is there any difference between vertical line and rotation movement? Or are they the same or are they covering two different concept that should not be mixed?
They should not be mixed.
Book, novel
A novel is a type of book.
We still need those two words. We should not get rid of the word novel just because it is also a type of book.
Book and novel are same in some ways and are not in others.