The deep breathing adds more oxygen to the blood. The gentle stretching then brings more blood to the tense area, and the highly oxygenated blood delivers nutrients and carries away toxins, helping to cleanse and relax the stiff or painful area.
The slow, deep breathing used in all qi gong exercises is a natural relaxation method than can help to ease tension in all areas of the body, not just in the muscle groups that are being worked here. Remember to mirror the position by completing the exercise in equal numbers on each side of the body. That way you ensure that you are providing equal benefit to the muscles and tendons on each side, which will help to keep your body in proper alignment.
From the 'wu ji' starting position, lift the left foot and step to the left so that you feet are now shoulder's width apart. The head should remain lifted up, but not tilted. If it helps to get this positioning correct, imagine that there is a string in the middle of your head that is gently lifting the center of the top of your head away from your body and towards the ceiling. This helps to ensure correct posture throughout the exercise. Keep your eyes focused ahead of you on some point in the distance.
Move your hands from the 'wu ji' position in front of your thighs so that they are now next to your hips, but your wrists are now bent so that your palms are facing the floor. Check your pelvic positioning - it should be in the tucked position and your knees should be slightly bent.
Inhale deeply and slowly as you turn your head slowly to the left, and exhale and you turn your head to look as far backwards over your left shoulder as is possible for you. Do not turn the waist or lift or move the shoulders. It is only your neck and head that should be moving. Fix your gaze at some distant point over your shoulder and gently hold the stretch.
Now slowly begin to turn the head back as you inhale and exhale as you return to the starting position. Pause for a moment, then inhale deeply and slowly, turning your head to the right. Again, be sure that your hips, waist and shoulders all remain still and that the source of the movement is your head and neck muscles.
Exhale as you turn your head as far back over your right shoulder as is possible for you, fixing your gaze once again at some point in the distance. When every last bit of air is expelled from your lungs, begin to inhale again, moving your head slowly back towards the front and returning to the starting position as you exhale.
You should perform a minimum of eight sets of this stretch in order to gain the most benefit. This is a helpful exercise that can be performed just about anywhere. If you need to deepen the stretch, then as your head is turned over a shoulder, gently press the palm of the opposite hand downwards - qigongsecrets.com