When I engage in a sport activity like soccer or tennis within 20 minutes I develop a dull pain in the mid section area. It envelopes my mid section like a tire. It makes walking and running very laborious and painfull. The pain sometimes shoots down the front of my leg halfway to the knee. The pain does not stop when I stop the excersise, it is not as severe but I have difficulty walking for a day afterwards. This has been going on for a while, and rest does not seem to help