OK, first of all, I need to say that for most of you, tennis balls (or any air filled ball) is not going to do the job. They just compress too much and can not provide a therapeutic level of pressure (in my humble, limited and biased opinion). You need tools that are sturdy and dense to provide the pressure that your muscles and tendons need and your nervous system is craving!

This little ball is perfefct for working out the sole and arch of your foot and you can always find at least one of these under my desk. It is around $6 on Amazon and shipping is free for Prime Members. I usually have a couple available at my practice as well.

Foot Rubz with Foot on Touch Factor Massage