stele3:

preved-medved:

shakespearesconesandstars:

So, it’s at three in the morning that, after seeing a gif, I begin having revelations/disturbing thoughts/deep contemplations about the bionics and biology of the Winter Soldier’s arm. And, of course, at three in the morning, that’s when I start assembling pictures and diagrams. 

Here’s a normal shoulder, and then the Winter Soldier’s. What gets me is that it’s not just a plug-in prosthesis that joins neatly up with his shoulder joint and the bone structures there. 

As seen here, all of these muscles: 

are what you need to actually move an arm and shoulder. With structures even as far down and centralized as the pecs, the muscles there bunch up in the shoulder region. As seen on the Winter Soldier, all of the places where his upper chest/pectoral, and shoulder muscles should be bunched up are (whether partially grafted with or entirely) metal. 

Here, (on my phone) I drew out how more natural muscle patterns would be going without the interruption of the prosthetic. And here’s what looks to be going on: 

At the seam of the prosthetic, we can see a glimpse of material that seems to extend down, following the basic lines of where musculature would need to be to support movement- which leads me to believe that at least in the front, that metal had to be extended (or at least extended by way of more flexible wiring to at least graft and connect to existing muscles and nerves) down through his entire pectoral muscles. Sure, his entire pec might not have to have been recreated/replaced by metal and wiring, but I’m getting the feeling that the lighter colored metallic structure at the seam continues farther down into his chest in order to connect to existing muscles and nerves. Depending on how far down they had to take things, they may or may not have had to anchor the pec and under arm metal structures to his ribcage. 

Now, onto the back. 

The scapula and other skeletal structures in the shoulder area are all pretty necessary for movement, and although Bucky only seemed to lose below the upper bicep after the fall, the scapula alone couldn’t support the weight and power of his new arm. So, I’m guessing that they left both the scapula and collarbone, but would have needed to reinforce both bone structures with metal (this includes shoulder joint and socket, if they were still intact enough); and all of that, they’d need to anchor to his spine/rib cage to keep the weight balanced and make sure the muscles and cartilage didn’t rip and tear with the weight of the arm during standing and fighting and such. 

As for what they’d do about the muscles needed for arm movement in the back, I don’t have a clue- for weight and efficiency’s sake, they probably would have done their best to preserve and connect existing nerves and musculature on his back to the arm, after reinforcing bone structures. Given that the muscles in the back and shoulder connect to the spine and neck, that would be a whole lot of metal to try and anchor down if they replaced everything back there with straight up metal (as opposed to connecting wiring and such to the muscles already there). 

So, whether or not this taught anyone new, I feel it’s certainly an interesting line of thinking, to consider just how far and how deep the socket, reinforcement, and overall prosthetic goes into the musculoskeletal structures of his chest, torso, and back. As for the wiring required to get the level of responsiveness and finesse that his arm has, I can’t begin to imagine how they had to integrate their technology into his nervous system- that might be a post for another day, and possibly by someone who has more than a basic understanding of anatomy (that’s what degrees are for!). Are there any more lessons to this? Well, I’m a biology geek and a Marvel geek, for one, and once more, we can reinforce that Hydra is fucking terrifying and horrible organization- albeit, one with surgeons that had remarkably, ridiculously, spectacularly advanced technology and understandings of bionics even in the 40s. 

Ooh, nice, this is super well-researched and full of troubling implications. I love fics and stuff that really get into the possible functionality (or lack thereof) in the metal arm.

I’m of the very firm opinion that there has to be some kind of mesh stretching over his pectorals to anchor the arm to his sternum. I did a lot of thinking about the weight of the arm here and how Bucky’s posture and stride compensate for the weight here; from both the math and SebStan’s excellent physical acting, it’s clear that the arm weighs a fuckton. Far too much to be held in place by the shoulder or pectoral girdle: the collarbone is a delicate beast (I say that having broken both of mine in my life) and not something that you want to rely on to hold up anything. Same with the ribs. The scapula, meanwhile, is literally not attached to any other part of the skeleton. Nothing locks it into place, not like the shoulder or hip ball-and-socket joints; it just kind of floats over the ribs, kept there by the many, many back and shoulder muscles.

So my guess: metal reinforcement of the collarbone, ribs, scapula, and probably the upper vertebrae (at least C7, the knobby guy at the base of your neck), along with sub-dermal meshing that attaches to his sternum and between his scapula and spine to keep his pectorals, trapezius, and rhomboids from tearing every time he throws a punch.