Cervical lordosis is a curve in the cervical spine, the area of the spine which contains the neck vertebrae. This curve is entirely normal and in fact desirable because it helps to stabilize the head and spine, but when the curve straightens out, becomes too deep, or faces in the wrong direction, it can become a problem.
If something's canonical, it follows a principle or rule, usually in a religious or church-related situation. It is also used in mathematics, music and can refer to something reduced to its most basic form.
A classic is a book accepted as being exemplary or noteworthy, for example through an imprimatur such as being listed in a list of great books, or through a reader's own personal opinion.he terms classic book and Western canon are closely related concepts that can confuse the student of literature but that are not necessarily each identical with the other. A canon refers to a list of books considered to be essential and is presented in a variety of ways.