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).
Alkali Metals and Halogens. Alkali metals and halogens are the chemical elements which are members of the group 1 and group 17 in the periodic table. They are called as s-block elements and p-block elements respectively. Alkali metals have the differentiating electron which enters the s-orbital of the valence shell.