Both Rodin and Michelangelo took interest in the human body.
Rodin put a lot of emphasis on the the expression and feeling that the sculptures portrayed particularly in the nude which he is quoted to say, “The form and the attitude of a human being reveals the emotions of its soul. The body always expresses the spirit whose envelope it is. And for [he] who can see, the nude offers the richest meaning.” He also use the medium to his advantage to create or recreate a scene to a story or evoke strong feelings.
The Thinker posed to evoke deep thought and contemplation and depending on the angle you look at the statue, like in the picture, you can even say that the Thinker has come to an epiphany or is in the process if such. The statue isn’t in a relaxed posture but in a more rigid, dynamic pose that illicits action.
Fallen Caryatid Carrying an Urn shows the scrunched up body weighed down by the Urn which also shows how much a person could be crushed by the burdens they carry.
Michelangelo on the other hand focused more on the idealized human body and image
The sculptor of the Young Archer depicts a child whose body is fit and muscular, not a body you would imagine on a child, however it would fit the occupation of an archer. The statue is shown in a free and open expression that does not shy away from showing off his body.
The statue of David is the image of an idealized man. The limbs, hips are counterbalanced to depict a naturalistic and humane stance to the subject. The posture is known as Contropposto which was originally observed in the sculpture, The Spear Bearer by Polykleitos also known as the Canon or the ideal model that others should study and copy. The subject David is shown to have an athletic build with intricate details to anatomy.