Purpose: This spot is one of the most popular and is right under your feet — literally. It lies in the center of the arch muscles of the foot. This is one everyone knows about. No massage is complete without a foot massage!
There is another reason why this spot is significant. The skin of the feet has a disproportionate number of nerve endings, like the face and the hands, yet the feet are generally abused or at least neglected.
The plantarfascia is exactly in the center of the bottom of the foot, halfway between the heel and the ball, and halfway between the inside and outside edges (perhaps slightly closer to the inside).
The arch muscles generally feel best when pressed on an angle, for example towards the outside of the foot. But this is a minor point: any angle will do!
It isn't difficult to understand why the arch muscles of the foot would harbor a massage. They are, after all, the hardest working muscles in the human body. Our feet absorb an incredible amount of punishment, yet usually feel no worse than just stiff and tired. Injury here is common, but not nearly as common as you might expect.
SMR to this area is believed to increase circulation and nerve mobility. Also, in swimmers who experience a foot cramp, this may be beneficial, since it may break-up bound fascia or decrease muscle tension.
Stand and roll a tool (tennis ball or baseball) under the base of your foot. Roll on the ball slowly for 30 - 180 seconds. If you find a tender spot, go slow!
This was an excerpt from the Mobility for Swimmers System, to pre-order the product go to: http://www.swimmingscience.net/p/products.html