I live in a condo and we have a lot of land around us but I don't let them off the leash just bc I worry about coyote's. I walk them and we play ball in the house. I take them to parks too. I look at it this way........safety is more important than running free bc if you let them loose and needed to chase them you couldn't with your bad knee and feet.
So I think you are doing the right thing. As long as they get play time and outside time they are happy
