First, read the English article below.

While stretching won't remove the knots, it can reduce your pain and definitely keeps future knots at bay. The following are exercises that you can try. These exercises, also known as shrugs, can help release tension in your neck and shoulder area, a common place for knots in your back to form.  Sit upright in a chair, preferably one with a straight back. You can also sit on the floor or stand, but make sure to maintain good posture. Bring your shoulders up to your ears. Roll them forward and then down in a clockwise motion. Repeat this exercise in the opposite direction: up, backward, down (counter-clockwise). Do two to four reps several times a day. This stretch will help blood flow into your shoulder blade area, which is a common site for knots.  Begin by placing your hands palms-down on your shoulders. The right hand goes on the right shoulder and the left hand on the left shoulder. Bring your elbows together, keeping your hands on your shoulder. You should feel a good stretch in your shoulder and upper back area. Hold this position for three to five seconds and take deep, even breaths as you hold. Then relax. Repeat this exercise several times throughout the day. This exercise can help release tense and tight muscles in your upper back and shoulder area.  Sit or stand with your arms at your sides. Squeeze your shoulder blades together. Hold this tension for a few seconds and then relax. Repeat several times throughout the day. Imagine a string pulling your shoulder blades back and down. Do not just extend your chest forward. This exercise will help stretch and release tension in your shoulders.   Bring your left arm across your chest. Reach as far across your chest as you can.  Hold your left arm in place at the elbow with your right arm. Hold the stretch for 30 seconds, then relax. Repeat the stretch with your other arm. " These exercises can help stretch the muscles in your lower back, although they aren’t as effective for the upper back or shoulders.  Sit on the floor with your legs tucked into your... 

Now, please write a short abstract for it in Vietnamese. Abstract:
Thực hiện các bài tập kéo giãn cơ. Nhướn vai. Giãn cơ vai bằng cách di chuyển khuỷu tay. Ép hai vai vào nhau. Giãn cơ vai bằng cánh tay đối diện. Động tác "khép chân và lăn". Động tác kéo giãn đầu gối-ngực. Sử dụng một số động tác pilates. Đan hai bàn tay và kéo giãn chúng trước mặt. Giãn cơ cổ.