I feel very lucky that I’ve had multiple excellent teachers in Tai Chi. There’s nothing that can replace in-person training with someone who can correct and guide you towards what relaxation and proper structure feel like. That said, online videos can be helpful, and I’ve enjoyed the videos I’ve seen of a tai chi practitioner named Adam Mizner. His explanations are clear and concise, and his demonstrations of the martial applications of the tai chi principles are very impressive.
In this short video, he discusses the importance of sinking one’s elbows. He uses the Chinese term “song” (or “sung”), which has the meaning of relaxing as well as sinking. This relaxation creates a heaviness that increases solidity without increasing tension. If the shoulder and elbow can stay relaxed when a partner is pushing up on the elbow, you can rest your entire body weight into it, making it almost impossible to lift.
Hope you enjoy this video.
Brush Knee & Push 