Contrapposto is a sculptural technique in which one hip is lower than the other because a knee has been bent or a leg has been moved forward or backward. It shows the artist's better understanding of anatomy. It is first exhibited in the ancient GreekKritikos Boy[?], and can also be seen in Michelangelo's David.
... at) and
means "they are in me".
"-aham" (I) in the second line is nominative. na caaham =
"...and not I....", meaning "but I am not...".
"teshv-" (in/at/by them) at ...