1. Lie on back with a "peanut ball" under your spine, just above your lower back. (You can also tape together two tennis balls.) Hold your hands behind your head. The peanut ball should be perpendicular to your spine with one ball on either side of the spine. Raise your arms over your chest and alternately reach over your head for 5 reps with each arm. Move the peanut ball up your spine two inches at a time, repeating the movements, until the ball is just above your shoulder blades and below the base of the neck.