Often after an acute injury of the knee the quadriceps muscle will not contract, which is called âquad inhibition.â. Inability to straighten the leg. Athletes with acute patellar injuries may find that they cannot flex the knee joint fully or straighten the leg. This may be exacerbated by swelling of the knee.
The alkali metals are a group (column) in the periodic table consisting of the chemical elements lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr).
The alkaline earth metals are found in group IIA of the periodic table, which is the second column of elements. All of the alkaline earth metal atoms have a +2 oxidation state. Like the alkali metals, these elements are found in compounds rather than pure form. The alkaline earths are reactive but less than the alkali metals.