Based on what you have described, my guess would be a stress fracture. It is not unusual for a stress fracture to not show up initially in an x-ray. A diagnostic ultrasound or MRI might be more helpful.
Posted By Vivian Abrams DPM on April 20, 2006 at 21:15:46:
A layer of gel combined with a foot cover to help protect metatarsals and toes from friction and pressure. It also ideal for cushioning the ball of foot and provides warmth for people suffering from arthritis or poor circulation to the toes.