In bowling, there are a lot of things that separate a really good bowler from an average bowler.
One of these essential things is having an unmuscled arm swing. I know a lot of people think that the amount of speed that is put on the ball is due to the amount of muscle you use. That isn't true. Below are a few things that will help you develop an unmuscled arm swing.
1. To prove that you can develop proper speed without a lot of muscle take your bowling ball, extend your arm outward like you are starting your arm swing, now just drop your arm. If you notice gravity is dropping your arm, it should be swinging back and forth (like a pendulum). You are feeling what a proper arm swing feels like.
2. Now granted, just doing this will not make you the next national champion. You have to square your shoulders and be properly balanced throughout the arm swing. What will help you do this is keeping your eyes locked on a target (preferably the arrows on the lane).
3. It is not a difficult concept to grasp that when you start your push away you should push toward your target. Now all you have to do is maintain a proper arm swing and you should hit your target the majority of the time.
Before you go out and join the PBA thinking you have discovered the secret of bowling, you might want to practice these concepts. I hope this will help improve your game like it did for me.