The localized pain with a stress fracture is usually exercise-related and increases with activity and either abates with rest or persists at a lower level. A local bony tenderness is common. If training continues, the pain progressively worsens and is brought on with less intense activity.
The most common sites for stress fractures are the tibia (shin bone), metatarsals (foot bone), and fibula (outside lower leg bone) and navicular (foot bone, especially with sprinters and hurdlers). Sports associated with specific stress fractures include rowing and golf (ribs), baseball pitching (humerus), and gymnastics (spine).
Of the many risk factors for stress fractures that have been proposed, training errors are probably the most important. They include a sudden increase in the quantity or intensity of training, introducing a new activity (eg. Hill running), poor equipment (eg. worn-out running shoes), and change of environment (eg. changing surfaces from asphalt roads to cement sidewalks). Other risk factors include low bone density, increased age, dietary deficiencies (ie: low calcium intake), abnormal body composition, menstrual irregularities, disordered eating and biomechanical abnormalities (ie: excessive pronation). Often, a combination of factors is involved. Among athletes, females have been reported to be at 1.5 to 3.5 time’s greater risk of stress fractures than makes. Studies suggest that the difference is not related to athletes’ sex per se, but to factors such as amenorrhea (absent period), bone density, and diet.
Often an X-ray will initially not show any signs of a fracture. It is only after it has begun the healing process that the fracture site will show up on X-ray as new bone formation. If the X-ray is negative, a procedure called a bone scan is then used. This procedure uses radioactive markers to detect stress fractures. When a stress fracture is diagnosed an immediate 6 weeks minimum rest periods is required