system
Given the following post, respond as if you're commenting on Reddit:
human
[MCU] How does Iron Man's armor affect his flexibility depending on bulk?
gpt
They limit his flexibility but in good ways.  

The joints of the Iron Man armor are designed to protect Tony's body so that nothing gets bent too far or in the wrong way.  For example, the armor's back plates are designed so that Tony can bend his torso forward and back, but they also protected Tony's spine from getting crushed when Stane had him in a bear hug.  Another example would be when he had vehicles dropped on him in the battle at the airport, he suffered multiple contusions but no sprains or fractures.  

Regarding bulk, the only armor Tony's used with a significantly different level of bulk would be Veronica, which was deployed against the Hulk in South Africa.  This armor worked by having Tony inside the torso while wearing another set of Iron Man armor.  Veronica's limbs would reflect Tony's movements, but Tony's arms and legs were not actually inside Veronica's arms and legs.  This meant that Veronica's flexibility was actually *better* than Tony's default armors, because there was no longer any concern about bending Tony's limbs in unnatural ways.  This can be seen in moves such as when he could bend Veronica's arm in an unnatural way to punch Hulk behind him.