I read in the book that 1. First of all, you should stand up straight, press your hands on your sides, and make the maximum circle on your shoulders from top to bottom (you will consciously hold your chest out and abdomen in when you return the stroke) 60 times (preferably above). 2. Shoulders do maximum circular motion from top to front (like a cold body contracting forward) 60 times. 3. Put your hands on your hipbone naturally and shrug (like pinching your neck) until your sour shoulders can't shrug. The three things I said are best done more than twice a day, and the effect will be faster. People who have physical strength practice when they have time until they can do nothing. Stick to it for about half a month, and you can touch the clavicle with a slight depression. The longer you persist, the more obvious the effect will be. If you do this, you can stretch your arms back and forth as far as possible from bottom to top (arms and back are preferably 90 degrees) and repeat until you can't do it. This action will make your flat back and beautiful shoulder blades stand out slowly. I tried these moves and persisted for 10 days. I saw some depression in my collarbone, but I couldn't hold on any longer. I am really tired. I hope you can insist. Anyway, I did it, and it felt good. I don't know the rest. Persistence is the most important thing in sports. (Note: Don't expect too much, you will feel ineffective. Don't always watch training. 10 Once every 20 days, you will be surprised. )