Basic Posture for the Exercise:
Sit firmly on a chair or stool, which should be lower than your knee level. Sit near the front edge so that the thighs are free from the edge.
Keep your knees apart at the same distance as your shoulder width. Keep your legs straight down at the right-angle (90 degree) to the floor.
Keep both feet flat and firm on the floor, the feet parallel and point straight forward.
Always keep your body and the spinal column straighten up by pulling your abdominal muscles in while pulling shoulder blades to meet together at the midline of your back. Also, keep drawing your chin backward with your face looking straightforward.
The hands rest on your thighs, close to the body, keep the palms opened and facing up.
Breathe in and out slowly and deeply through your nose, without making any noise. Aim the breath deep down to below the navel, with the abdomen always staying in and the chest expanded mainly upward and forward.
I thank Dr Taworn Kasomson for introducing me to these exercises that he developed.