The Pathogenesis of Metatarsal Stress Fractures

As seen with Dancing with the Stars Tom Delay, stress fractures of the feet most frequently occur in the long bones called Metatarsals. They start with either an impact to the bone sufficient enough to bruise the bone or with small repetative flexing forces being placed on these long bones. The slang term "march fracture" evokes a good mental picture of a soldier marching longer distances than he is used to and thus causeing a contusion (bruise) to the bone. As mentioned this is just the start of the process.
The next phase is the increased activity of bone cells called osteoclasts. The bone structure is continually in a state of turn over and these osteoclasts are responsible for removing weak or damaged bone. For a period of approximately 3 weeks after the initial injury these osteoclasts eat away the damaged bone thus making it gradually weaker. It takes this 3 week period for the rebuilding cells, called osteoblasts, to show up on the scene to begin the re-building process. However, if the person afflicted continues to be active the osteoblasts can not get the job done and a hair-line crack develops in the bone and this is the stress fracture. Only adequate rest of the injured bone will alow it to heal