What I was told by an agility instructor is the A frame and not jumping the appropriate height on hurdles is the obstacles that may cause stress on joints. Of course a dog can blow out it's knee anytime there is running and turning sharp corners involved. I wouldn't think a dog jumping through a hula hoop would not be too stressful as long as it isn't held too high.
__________________  Karen, mama to Macy and Molly  It is easier to fool people than to convince them they have been fooled. (Mark Twain) |