One Arm Shoulder Flexor Stretch

Shoulder, Back, and Chest Stretches:

Method:
Stand (or sit on a backless chair) upright with the left arm behind the back and the elbow bent at about 90 degrees. Place feet shoulder-width apart with the toes pointing forward. Grasp the left elbow with the right hand. Pull the left arm across the back and up toward the right shoulder.

Affected Body Part:
Most-stretched muscles: Left pectoralis major, left anterior deltoid, and middle deltoid.
Lesser-stretched muscles: Left levator scapulae, left pectoralis minor, left supraspinatus, left serratus anterior, left coracobrachialis.

If you cannot reach the elbow, then grasp the wrist. When pulling on the wrist, it is easy to pull the arm across the back, but remember that the best effect comes only from pulling upward as well as across. Also, keep the elbow locked at a near-90-degree angle. Changing the alignment of the back will also influence the magnitude of the stretch. If you cannot keep the back straight, arching the back is preferable to bending at the waist. Just be careful; it is easy to lose balance when doing this stretch while both arching the back and standing up.