The best way to work stabilizer muscles is with a slave. Bosu balls are boring and why soil a yoga mat when my slave cleans my beautiful sweaty feet during my workout? I hope the slave tastes the footjob I gave someone else earlier today. I get a good stretch with one foot on his face and the other on his useless soft cock and balls. This is better than step aerobics and even the slave gets a good workout. A few more weeks and we will see some results!