Hi there,
I'm not Cathe but perhaps can assist as an instructor myself.
The answer to how to get clients to use the ball is gradual introduction, patience and time. My members first said "We do not want to use this thing in muscle conditioning class." Period! This is because I was doing too much too soon, as an over eager instructor. So I backed off. We began just by sitting on the ball for a few minutes each class to get them used to it, with a step set up in front of us. If they found their balance was shaky they could place their feet on the step for support. The next class we progressed to lifting our heels off the floor one at a time and adding leverage with our arm on the opposite side. Everyone just did what they could to maintain balance even if they weren't following my cues.
Now they have progressed so far we use the ball for everything - aerobics, balancing classes, abdominals, and they always say they feel like kids again and forget about how hard they are working. I am so glad I took the time to educate them about the benefits while being sensitve toward their apprehensions.
Bottom line, yes, we as instructors can sometimes get so excited about what we learn in workshops or see in videos that we want to implement it all at once. But the clients want to feel like they had a good session or class with you, not that they spent their entire hour getting their heart rate up from pure frustration.
I love the stability balls and could use them all the time. I have to stop myself and chill out!! :7
Good luck!
-Roe
PS: The knee stress could be from them working so hard to stabilize the ball and keep it from rolling away. Perhaps placing the ball up against the step or a wall would make them feel more secure until their stabilizer muscles become stronger.
