How do you ask questions in Facebook groups without it showing up elsewhere?

[Cassie]

I've joined a closed group (that's closed, not secret) on Facebook that is a support community for a medical condition I have. I want to post questions, but I've noticed that when my friends post questions in groups I can see it in my activity ticker on the side. Is there any way to ensure no-one but the group members see it?

[G]

You can find here what are the privacy options for facebook groups
https://www.facebook.com/help/privacy/groups