Anatomy of the upper limb and Simon-specific limb loss research + theories
*This post contains spoilers for the end of the Iron Lung movie, as well as frank discussion of severe injury + death, medical terms, and illustrations of broken bones*
As promised, here is the infodump about how I think Simon's arm loss went and how it was possible :3 The first half of this is anatomy basics and then I get into more Simon-specific examples
First tho, my credentials for doing something really involved like this: I have a degree in scientific and medical illustration and I've studied human anatomy, injuries, biology and physiology extensively. Also I'm autistic and this is my main special interest XD
Now to start: Here is our Simon for these visuals. Say hi to him, he doesn't know what's in store for him yet (I'm sorry he doesn't have a face, human faces are my weak point hhdbcj)
Simon in the movie loses his left arm above the elbow during the climactic fight with the Blood Eel/the ocean itself. It becomes stuck to the surface of a pipe by what I am referring to as bloodvines - these are an aspect of the ocean/the blood eel, and they encase Simon's left hand and attach it to the pipe to try and trap him. In complete desperation to get free, he braces himself with his feet and, in a visually stunning display, pulls his own arm off.
As a baseline we're working under the assumption that this is absolutely mentally possible for Simon to accomplish. Where it might not be possible for someone weaker, Simon is shown to be incredibly strong both physically and in willpower. He wants to live; he'll do whatever it takes. It it also, as we see, possible physically. He's able to get his arm off and get free.
This raises a few questions though. Take a look at some basic anatomy of the upper left arm on our Simon:
Muscle-wise, the shoulder and upper arm are pretty complex structures. A lot of connections and attachment points are involved in making the 360 degree motion we humans have in our shoulders possible, however luckily for Simon, most of those complex and tiny muscles are stored in the back. The three main muscles his limb loss would affect directly are the deltoid, biceps, and triceps (biceps and triceps count as one muscle each they just both have a few attachment points).
Bone-wise, this injury is technically simple. It's going to affect the humerus, the only bone of the upper arm between the elbow and the shoulder - in fact, it's part of forming both of those joints.
Knowing all this anatomy that forms the part of the body where Simon's injury happens, here are our reference photos:
These are stills from this moment in the movie. However, they're not great quality, so I also found this video posted to TikTok from the account of the SFX artist (ATXFX) who created this effect (video link: https://www.tiktok.com/@atxfx113/video/7629184974377323790?is_from_webapp=1&sender_device=pc )
Here, we can see where each fake arm was cut in order to create the ripping effect later achieved. This is our trauma site. With this trauma site decided, we can make a few inferences about what was affected and what problems this brings up and would cause.
Now to address the problems this raises. First off: the humerus.
The humerus is a long bone, one of the strongest in the human body - it is comparable to the femur, which is the longest and strongest bone and makes up the upper part of our leg. The humerus has a LOT of muscle attachment points as well as being part of two different joints, as stated earlier, and here is the very crucial thing about severe limb injuries and loss; these traumas almost *always* happen at the joint. The meeting point between two bones is the weakest part, and usually if an arm is going to be ripped off it's going to be at the elbow, or at the shoulder if things have gone *really* wrong.
However as is clear from the reference photos, Simon's arm is ripped off about a third of the way up the humerus. Right on the main shaft. Where it is almost at its strongest.
Damn you Markiplier for making my job harder (/j), alright, here are my theories for how this happened:
One method for explaining this, and something that is definitely an option in fanfiction, is that there is a moment we as viewers miss in the movie where Simon's arm is hit with something hard enough to break it along that specific point on the bone. Personally, I intend on using this interpretation in a fanfic, mostly because I want him to be holding the piece of Ellie's tooth that he breaks off for... reasons. However, my other idea for a blunt object that could do this would be the fire extinguisher. This injury in the moment could be self-inflicted or accidental as a product of the ship being thrown around.
Another method: It was the bloodvines. These vines are shown to be extremely damaging - Simon's hand starts to mutate and deform almost as soon as the vines encase it and start to spread, and wherever they touch Simon's skin is left horribly marked and damaged. They're clearly hurting him with every second they touch him, and I believe that it would be possible that if he had begun to rip himself free and they were able to grasp his bone in their effort to contain him, the force of being gripped combined with the damaging, almost necrotizing nature of the vines would have snapped the humerus at that point and freed him.
A third method that seems slightly less feasible, but possible: Simon had a somewhat-recent bone break at that specific point on his arm. It would've likely had to have been a complete break, something that went all the way through the bone, and it's not hard to believe that it wouldn't have healed correctly given his residence in prison probably receiving less-than-ideal nutrition. A strong enough force or pressure would've snapped the bone along a pre-existing fault line a LOT easier than it would a healthy, whole bone
So, these are the main three theories I came up with on my own, but it still seemed like a long shot. So I consulted Reddit. And lo and behold, the wonderful Iron Lung fandom had already come up with the final piece of the puzzle.
Sustained radiation damage, alongside causing a huge amount of damage to the soft tissue cells in the human body, also mutates, weakens, and breaks down bone cells. I haven't yet done an Iron Lung watchthrough where I count how many times he uses the camera (last time I was busy counting concussion opportunities) but it's safe to say that Simon is exposed to a LOT of radiation over a fairly short period of time. Yes it's muted somewhat by the hull of the Iron Lung but like. We see him puking up and coughing blood, that's not normal. His mutations at the very end also speak to this problem, which may also be being accelerated by the bloodvines. If the spot on his humerus where his arm broke off happened to be at the right stage of radiation damage, it would make perfect sense why any of the above factors would've snapped it. It might've even been possible for the bone to snap on its own, without any outside force (pulling wouldn't do it though - Simon would have to jerk his arm to the side to get.the necessary force).
I have included a diagram of all the kinds of bone breaks Simon may have sustained along his humerus during this process, partially for visual clarity and partially so that my fellow writers and artists can feel confident in their descriptions :3 I encourage everyone to look into these specific kinds of breaks to best describe what actions cause them!
Alright, we're almost done. Final things I want to address is if you intend to have Simon survive at the end of his ordeal in the Iron Lung, in one way or another, and he has already lost the arm, there are a few things to keep in mind. One of those is the brachial artery.
This is a major artery that runs through the armpit and down the back of the arm. It supplies blood to the whole of the arm, and while it doesn't bleed *quite* as fast as other branches of arteries it will still cause severe blood loss in a matter of minutes. Solution! Tourniquet that man at once. The sooner he gets a tourniquet applied to what's left of his arm (placed high as close to the armpit as possible), the better off he'll be
There is also the risk of shock, which is compounded by blood loss and just total system overwhelm from pain and bodily harm. Shock can definitely be lethal and often is, and at the end of the movie Simon's lack of immediate pain response to having his arm ripped off could be seen as an early sign. If you want him to live, fixing that blood loss first is a necessity, then getting him to a place where he can be stable and hopefully pull through. He's a fairly strong person so his likelihood of dying of shock isn't as high as it could be, but the risk is never zero.
I did want to mention that it's always a good idea to read accounts from people who have lost limbs in the same place/same way as Simon has in order to represent the experience of living without a limb more accurately. Reddit's r/amputee is honestly probably a good place to start, and you can find an endless amount of accounts from real people living with this disability.
And that just about covers it! I do have more I could discuss on this topic if anyone wants me to get into the really nitty-gritty of things but for now, I'm starting here XD Thanks to anyone who read this far, I hope this is helpful! Go forth and depict anatomically-accurate previous bodily harm <3
