Subject: Am a musician in Chinese orchestra
Posted on: 2021-03-01 00:31:25 UTC
Personally I play the pipa, but we share a practice room with the erhu players. As far as I've seen, all of them play the instrument sitting down.
However, according to some answers on baidu.com, you have to attach a rack to your waist to be able to play it while standing up. I think it's because of the way the strings are positioned: you can't just hold it up by the 'stem', or changing notes would be extremely tedious.
In conclusion, you have to place the erhu on some flat surface, be it your lap or the attachable rack, to be able to play it.