Position your body crosswise to an exercise bench. Your upper back should rest on the bench, and your knees should be bent, as pictured.

 

Have your partner hand you a dumbbell so that you can execute a "cupping" grip, as pictured.

 

Bend your elbows slightly, and slowly bring the dumbbell back to a position behind you head. Keep your elbows slightly flexed. Strive for a good stretch at the bottom of the movement; however, stretch only as far as is comfortable. Do not bounce.

 

Return the dumbbell to the starting position, and repeat the exercise for the suggested number of sets and repetitions.