12345,
Perhaps it is proper body mechanics? I cannot imagine ‘without proper body mechnics’ that this could be done naturally.
15 years ago I trained in aikido - and the instructor pulled this stunt in class one night - the arm out one didn’t impress me that much but I could not figure how he could resist being pushed over when sitting cross legged on the floor with me pushing his chest. He never claimed this was chi but I would love to know how he did this if you can remember ?
I really can not remember. I think it was in Fighting Arts international (think you got that in the USA) but we are talking 10 years ago here.