When do I need to do my medical check? Before or after arrival in China?

I'm going to apply for z-visa and would like to know the Sichuan Province rules about the medical check. Is it accepted to be done in Germany before arrival in Chengdu and handing the Cert in to the authority or do I need to do full medical check after arrival? I was told that the medical is not required for the z type application here in Germany.