Thoracic extension in chair with towel (Thoracic extension stretch, over back of sturdy chair, hands behind head; 01)

Start in a seated position, with your feet on the floor.
Place a rolled up towel between the backrest and your upper spine.
Place your hands on your neck and interlace your fingers.
Point your elbows to the front.
From this position, lean backwards over the towel.
Hold this position for the required time.
After this, you can move the towel upwards or downwards.