Arm Swings Out and In warms up the muscles of your shoulders and mid back, which are important postural muscles.
Stand with your feet hip width apart and your knees slightly bent.
Gently bring both arms straight out to the side and then back in across your chest. As you bring your arms outward, you should feel a gentle pull across your chest. As you bring them inward and across your body, you should feel a gentle stretch in the back of your shoulders.
To get a total body warm-up, shift from side to side as you perform this exercise.