single leg squats will do the same thing but better IMO. You won't find a court as unstable as a swiss ball
Creatine works for some people, it didn't for me. All I got was pumped up muscles - like when I carb up. I didn't jump any higher or lifter any more. If you eat a lot of meat liek I do, it won't make as much of a difference. Vegeterians get better results
honestly if u are training for athletics just give the swissball a try. try kneeling on it fisrt doing an exercise.
i think it will make oyur normal squat form better.