Aussie need more activity

Question
I rescued a female 1 yr old from the pound about a year ago.  She is what they call a "yellow".  She has been spayed.  I know she needs a lot of activity and I am physically unable to walk much.  I take her out in our back yard and throw the Frisbee and she fetches it a couple of times and then goes back through the dog door and watches me through the sliding glass doors.  The weather is cool.  I take her back out and throw the ball and she goes back inside.  I got her a high jump, but she won't use it outside.  So, we now have a doggie high jump in the living room.  Any ideas as to why she hates the back yard?  She likes to go out in the car and walk other places.  Also, any ideas as to how I can exercise her?

Answer
Perhaps she was kept in a yard by means of an electronic collar and underground fence.  Sometimes, this can cause a dog to fear being out in the yard.  Or, she may never have had proper social experiences when young.  One thing you can do is to pair being outside with good things, such as a favorite food, and try to gradually lengthen the time she is willing to remain outside.  Perhaps, if she has herding instinct, she would enjoy a bubble machine (the bubbles are chicken flavored) You can also give her some mental exercise indoors, which does act to tire the dog out, by providing some puzzle toys.  There's a cool site, www.activedogtoys.com, which has a good selection.  I also like Premier's Twist and Treat toy.