When children look very awkward when they run, they usually have an imbalance in their muscles, or muscle or nerve damage. Telling an awkward child to change his form won't help and will probably just make him self-conscious. The child should first be evaluated by a physician for conditions that affect nerves and muscles. If none is found, the coach should have the child repeat the running motions over and over until the brain can coordinate the body's motions about his center of gravity. The faster he runs, the more likely he will be to acquire a running form that is efficient and does not waste energy with unnecessary side movements.
Your center of gravity is the spot in your body with equal weight in front and in back. Every motion you make is aimed at keeping your body balanced around your center of gravity. When you move one part of your body forward, you move another backward to keep you from falling. When you move your left leg forward, you automatically move your right arm forward and your left arm backward. People who don't do this look funny when they run. You can't talk a person into efficient running form and you cannot think yourself into good running form. To correct poor running form, go out and run every day and when you are in good shape, start running short interval sprints as fast as you can.How to run faster