Nnnnot quite fixing it! The problem isn't in the shading, it's in the pose. Try holding your arm down that straight, it's uncomfortable to hold and makes him look more tense and awkward than he should!
arms usually retain a slight bit of bend to them when relaxed, rather than falling completely straight. Same for fingers and even legs!
EDIT: you should also play around with his shoulder, looking at it a bit zoomed in it looks like his arm is kind of pasted over everything thanks to the lack of transition between his chest and arm. Pull the arm out a pixel, give it a proper bend.
and if you're specifically going for the hand on hip thing try to imply the arm bending behind the back some!