Leg pain is also frequently a sign of injury, such as the following: Muscle strain is a common injury that happens when the muscle fibers tear as a result of overstretching. It often occurs in the larger muscles, such as the hamstrings, calves, or quadriceps.
medical Definition of superinfection : a second infection superimposed on an earlier one especially by a different microbial agent of exogenous or endogenous origin that is resistant to the treatment used against the first infection
supernatant [technical] : denoting the liquid lying above a solid residue after crystallization, precipitation, centrifugation, or other process | a volume of ... (20 of 57 words, 2 definitions, 2 usage examples, pronunciation) oxforddictionaries .com /definition /english /supernatant