Tennis, probably more than any other sport, places a premium on rotational strength, lateral quickness, and shoulder stability. Plus, stronger, more flexible muscles mean a greater resistance to injury—and that's key for most players, who endure more pounding on hard surfaces than grass or clay.

So before you hit the court—or start feeling the effects of tennis elbow, a product of tight shoulders—it’s important to open up your shoulders, as well as your hips, and improve the side-to-side movements so crucial for chasing down volleys and firing off accurate backhands.

Try these 10 movements to improve your game, and you'll be winning more sets and matches, too.

Pete Williams is a N.A.S.M.-certified personal trainer, and the author or co-author of a number of books on performance and training.