If you have a disability speak to the organisers, If you can't go prone for any shot, then I am sure they will allow you to take it kneeling or standing.
The only thing is though, the target will be set as a prone shot and if you can not see it, standing or kneeling and you can't get prone, you will have to take the zero.
Somehow I made TEAM ENGLAND 2012 and 2013
Illiterate writer for AirGunner
The real Kung Foo Panda.