The tennis ball is great tool for reducing pain all over the body. (See link: http://wellerbodiespersonaltraining.blogspot.com/2012/05/tennis-balls-to-reduce-pain.html). Using it under your foot is also a great example of how our whole body works as a unit: By releasing the fascia in your feet, you can reduce pain in connected areas of your body.
Try this experiment: Reach down to try to touch your toes, do not push or bounce, just notice how far you can go. Next take a tennis ball and roll it under your foot (without shoes), and apply a little pressure. Take about 30 seconds for each foot. If you feel any sore areas, pause over that spot, point and flex your toes until the soreness lessens. Once you have done both feet try to touch your toes again; you will notice a big difference. This is because the connective tissue that surrounds our muscles forms lines that wrap around our body. The fascia at the bottom of the feet is also connected to our hamstrings and back. Releasing this fascia with the tennis ball helps everything “let go”.
Try this simple move twice a day (before and after your workout are ideal times). Some may feel more results with a golf ball, but the technique is the same. Whether you exercise or not, this easy step will help you move and feel better.