A weight of 5 to 10 pounds is held lightly in the hand (a filled gallon container weighs eight pounds). The muscles of the shoulder should be relaxed! The arm is kept vertical and close to the body (bending over too far may cause pinching of the rotator cuff tendons). The arm is allowed to swing back and forth or in a small circle (no greater than 12 inches (30 centimeters) in diameter). A properly performed stretching exercise may cause a deep achy pain, either in the armpit or down the inner aspect of the arm. This exercise can be performed just as effectively while sitting. The exercise should not be performed in people with acromioclavicular separation, glenohumeral dislocation, and hypermobility.