The Middle Ages (also called the medieval period) was a period of time that lasted in regards to a thousand years from your 5th for the 15th centuries. It is often subdivided into three periods with all the first being the Early Middle Ages, the other defined as the High Middle Ages, and also the third and final known as the Late Middle Ages. The most commonly affected joints are those in: hands, spine, knee, buttocks In 1988 researchers found that L-arginine's vast-ranging health and fitness advantages had been due principally to its position as a precursor to nitric oxide.