Master Liu is in his 70s here. Videos are available of him when he was much younger and winning competitions and things like that. Master Liu is one of the most skilled disciples of Hong Jun Sheng, and his push hands and particularly his qinna are renowned in Chen taiji circles. If you want to understand how good he is you can still go meet him in Shandong. The guy he's teaching is not a professional fighter, he's a professor of biochemistry doing cancer research and who has studied taijiquan since he was a kid. His push hands is also very good. What we are witnessing here is an explanation by the teacher about how things work, with a high level student/practicioner who knows how to apply only the force for the technique in question. This isn't a demo, nor is it faked. It's teaching.

看到他是堅料喔!