I have read a lot about pushing hands and seen many videos on the topic, but some years ago I was first introduced to pushing hands with a partner in front of me as part of a regular morning practise I used to do with a gongfu exponent here in Beijing. We were practising Shaolin forms at the time, but to "take a break" at the end of our practise we engaged in pushing hands. As we approached each other to being the pushing hands set he wanted to teach me, I was very relaxed and expected this to be sensitivity training. However, he used a lot of resistance to my movements and when he attacked he offered significant resistance to my deflections. Afterwards, in my less than adequate Chinese, I asked him about this and he told me that the softer version is used to build sensitivity, but that the harder, resistive version is used to build strength for real combat.
I had never heard of this before. Is this a common training tool in taijiquan? Is it particular to some styles and not to others? It certainly made you use your body a lot more to generate the force required to deflect incoming attacks. Thoughts anyone?