A stress fracture is an overuse injury. It occurs when muscles become fatigued and are unable to absorb added shock. Eventually, the fatigued muscle transfers the overload of stress to the bone causing a tiny crack called a stress fracture. Stress fractures often are the result of increasing the amount or intensity of an activity too rapidly. They also can be caused by the impact of an unfamiliar surface (a tennis player who has switched surfaces from a soft clay court to a hard court); improper equipment (a runner using worn or less flexible shoes); and increased physical stress (a basketball player who has had a substantial increase in playing time). Most stress fractures occur in the weight bearing bones of the lower leg and the foot. More than 50 percent of all stress fractures occur in the lower leg. Pain with activity is the most common complaint with a stress fracture. This pain subsides with rest. It is very important that during the medical examination the doctor evaluates the patient's risk factors for stress fracture.
Temporal trends of serotypes from invasive pneumococcal disease (IPD) in Spain from 1979 to September 2007 under antibiotic and vaccine pressure were analyzed. A significant trend in pneumococcal conjugate 7-valent vaccine (PCV7) serotypes (except serotype 4) was found, whereby the prevalence increased from the early 1980s and decreased in the 2000s for all but serotype 23F, which began decreasing in the late 1980s.
The impact of various preventive/therapeutic strategies on pneumococcal evolution is serotype dependent, and the dynamics remain unpredictable. X-rays are commonly used to determine stress fracture. Sometimes, the stress fracture cannot be seen on regular x-rays or will not show up for several weeks after the pain starts. Occasionally, a computed topography (CT) scan or magnetic resonance imaging (MRI) will be necessary. The most important treatment is rest. Individuals need to rest from the activity that caused the stress fracture, and engage in a pain-free activity during the six to eight weeks it takes most stress fractures to heal .If the activity that caused the stress fracture is resumed too quickly, larger, harder-to-heal stress fractures can develop. Re-injury also could lead to chronic problems where the stress fracture might never heal properly. In addition to rest, shoe inserts or braces may be used to help these injuries heal. Major research is been done in Spain by Wellcome Trust Sanger Institute.