I frequently hear people questioning the benefits vs risks of doing kettle bell swings. While I am not yet a certified kettlebell instructor, as a physical therapist I am most definitely a swing enthusiast. When done correctly it is a great addition to your core and hip workouts. I myself use it for conditioning work. And although I don't consider it a primary shoulder exercise, it can help to promote scapula stability.
To learn how to safely swing I recommend working with a certified instructor. You can find one near you here. Having a coach to teach the mechanics is important to help learn the proper technique. Even though I'm not actively working out or at the Worcester Kettlebell Club, I still send Coach Evan Marcantonio videos to critique and for advice on progressions. Each time I learn something new.
Prerequisites that I look for to start to swing are good hip mobility and postural control. This video demonstrates some progressions which will help you learn how to swing correctly and get the most out of your workout with least chance of injury.
Using video can also help you to see where there are some corrections needed. For instance, at the top of the swing I am hyper-extending my back vs. completing the motion with hip extension and solid core. Brett Jones demonstrates a great drill that I will start to incorporate as well.
As you can see, the swing is a very safe and effective total body exercise when done correctly.
