I guess transformation functions like translate(), scale(), rotateX/Y(), etc.
don't go very well for animation of shapes,
since they upside-down the coordinate system!
And they make it beyond my knowledge reach. 

I generally advice to use the keyPressed() functions instead of the variables... except when the effect must persist as long as the key is pressed.
So, this works better:

1. void draw() {
2.   background(127);
3.   if (keyPressed && key == CODED) {
4.     switch (keyCode) {
5.     case DOWN:
6.       ;
7.       break;
8.     case UP:  
9.       ;
10.       break;
11.     case LEFT: 
12.       ;
13.       break;
14.     case RIGHT:
15.       translate(width/2, height/2);
16.       rotateY(radians(90));
17.       translate(0, 0);
18.       break;
19.     }
20.   }
21.   drawhuman();
22. }

(removing the keyPressed() function).
Now, moving the members in correlated ways is difficult and probably need more advanced coding, like using objects. You might want to do Internet searches about inverse kinematics, too.
A domain that interest me but I never took time to explore.

Thank you so much.I searched but I cant :S I dont find movement in 3d in processing example:(

I am not used to controlling animation with transformation functions and I personally find them confusing as the points are not actually where you see them. There is a good tutorial on how to accomplish rotations manually so that the points are actually where you see them:  http://processing.org/learning/trig/