While you are reading this article, you are probably comfortably sitting on your cozy couch. Just another thing about sitting, did you know how the Japanese call their "proper" way of sitting? It is touted as "seiza," literally means "sit correctly", derived from words "sei" (correct) and "za" (seat).
Instead of squatting or sitting directly in tatami mats, Seiza was introduced in the Meiji Period as a correct posture in sitting, legs are neatly folded, feet are together supporting the body, and hands are properly rested in the lap.
Sitting on your heels for a long time could be tough, and can make your limbs numb. You will be fascinated with the people still doing it as part of a tea ceremony and doing traditional arts like calligraphy, kado (flower arrangement), and such.
This sitting position also has meanings. It is a sign of giving courtesy (such as in the tea ceremony), and a symbol of apology when seiza is done with bowing.
Seiza is just one of the many ways of sitting in Japan. Aside from giving proper courtesy, it actually poses health benefits such as calming the heart, training core muscles (abdomen and back), improving posture, relieving lower back pain, helps with bowed legs, improving circulation and leveraging focus and concentration. But, overdoing it might cause knee pain.
If you plan to visit Japan and join a tea ceremony, you might need a little practice on this one! So get out of the couch, kneel, fold your legs, and sit the Japanese style!