Tui Shou (Push Hands) is one of Taijiquan's way of working applications and using the energies cultivated in the learning of the internal kung fu (taiji) form. This practice is something that develops over years. I believe it is why the best of the best in displaying this portion of the art are usually very old. Tui Shou must take place effortlessly. Do not use external force. Take a look at these masters applying their skills in the art of Taijiquan Tui Show.
Various Masters Demonstrate Tui Shou (Push Hands)