The first regular taiji class I ever taught was a beginners' class in Fulham, back in 1987. One of the students was a lovely old lady who had already learnt traditional Yeung style taiji. So whilst me and the other students struggled to achieve some sort of vertical respectability, she had absolutely no qualms about leaning forwards, and, I had to admit, it looked beautiful and far more spirited and vital than the rest of us. I told my teacher so, and surprisingly (I didn't know at the time that he had studied with Yeung Sau-chung) he admitted that the leaning forward posture may indeed be correct. And, if you watch the man himself, the great Cheng Man-ching, it is clear that he only ever approximates vertical – sometimes leaning forward, sometimes back, and sometimes to the side. So, our vertical posture shouldn't be a rigid verticality, but one that contains all angles. We want the vertical not to reject the plane it rises up from, but to contain, or rather be contained by, that plane. The image I have in my mind (body) is Chang San-feng's snake, rearing up from its coils. Whilst the active part of the snake is vertical, most of it remains flat on the ground, hugging the Earth.