Shoulders need to flexible and strong to stay injury free. Don’t think that just by breakdancing you will train them properly. Make them stronger and more flexibile than you need then breakdancing will be that much easier.
I do the basics for shoulder flexibility as shown in the video. Shoulder flexibility is very important for specific moves such as hollowbacks and airchair, it becomes less important for flares and footwork. However, with greater flexibility more moves are possible. If you aren’t spending at least 15 minutes a week stretching your shoulders you are wrong!