Basketball requires many overhead movements of the arms, not only for shooting, rebounding and blocking but also to get loose balls on the court.The most common exercise to stretch the muscles involved in raising the arms overhead is the elbow behind the head stretch.
But, this movement is rarely, if ever, seen in game play. Because it is a static stretch you may even overstretch the ligaments and tendons of the shoulder joint predisposing it to injury. Actively stretching the muscles of the shoulder is much safer and more productive in getting the muscles prepared for play.
For strength of the shoulders the front arm raise to the level position is usually advocated. But only raising your arm up to level, will in time, create a tight shoulder joint and to a good extent, a weaker shoulder joint because the muscles are not strengthened in their full range. To correct this you must raise the arm completely overhead. As a result you will both stretch and strengthen the muscles.
When you do the full range front arm raise your arms are fully extended overhead in the ending position. By raising the arms completely over the head, you strengthen the deltoid muscle (the main muscle involved in raising the arm in front) much more than when you stop at the level position. When you stop at level you rely on other muscles to get the arm to this point, not the deltoid, which is most active from the level position to completely overhead.
The front arm raise can be done with a barbell, dumbbell or a strength bar. Dumbbells are more versatile and enable you to do the exercise either unilaterally or in an alternating fashion. However, to place greater stress on the anterior deltoid the strength bar is preferred. In this case, the weights will be concentrated in the middle of the bar directly in front of the body similar to what occurs when you raise the ball in both hands.
Assume a standing well-balanced position with your feet shoulder width apart and your toes pointed straight ahead. Inhale slightly more than usual and then hold your breath as you raise your arms up and forward as high as possible. Keep your trunk in the same position throughout the movement and your arms straight or slightly bent if you feel any discomfort in the elbow joint.
Upon reaching the upper most position relax somewhat and exhale as you return under control, to the starting position. Then repeat for desired number of repetitions. Execute at a moderate rate of speed with perhaps a little bit of extra force at the beginning of the movement to ensure the full range of motion.
Heavy weights are not recommended nor are they needed for proper and effective execution of this exercise. Because of the long lever created by straight arms, a small weight becomes very heavy when you hold it in your hands away from your body. Usually 8-10 pounds will challenge the strongest men when the exercise is done with strict form. For most players it is necessary to start with 3-5 pounds for up to 15-20 repetitions. When this becomes easy, increase the resistance.
On more formation on this and other basketball related exercises, read Explosive Basketball Training and the second edition of Biomechanics and Kinesiology of Exercise