Tony Stark, the man behind Iron Man (Robert Downey Jr.), sustained several major injuries in the Marvel Cinematic Universe, but no part of his body was targeted more than Iron Man's left arm. In fact, the injuries surrounding Iron Man's left arm became a lingering Easter egg throughout the franchise — tying into the major twist that ended his character arc. Even with the rollout of MCU Phase 5 reminding viewers that it's been a whole phase of the MCU since Iron Man died, his legacy ensures he remains one of the most heavily discussed Avengers.
Debates around the meaning of all the Iron Man's left arm injuries haven't abated. With the emphasis on Tony's left arm, there was speculation that the injuries were The Avengers where his appendage was briefly spared from abuse.
Iron Man (2008)
Tony's first serious injury came during the film that launched the MCU, Iron Man. After being held hostage by a group of terrorists in Afghanistan, Tony and a fellow captive built an armored suit to help them escape. The suit, known as the Mark 1, and the arc reactor, were vital for Tony's survival, and also served as the precursor to every Iron Man suit Tony Stark ever wore. He used it to fight the terrorists while escaping from the cave, but at one point, his left arm got stuck in the rock wall. Later in the film, Tony was wearing one of his more traditional Iron Man suits when he returned to Afghanistan. Iron Man's left arm was then directly hit by artillery from a tank. Tony was seen using an ice pack on his arm and shoulder following the incident.
Iron Man 2 (2010)
In Ivan Vanko, also known as Whiplash, built two electric whips from miniature arc reactors similar to the ones Tony built. Tony put on his suit and faced off against Whiplash in the middle of the racetrack. During the fight, Tony Stark's left arm was hit by the electric whip multiple times, leaving his armor severely damaged.
Iron Man 3 (2013)
After his mansion was attacked by Eric Savin in Iron Man's arc reactor was also crucial, which saw the shrapnel getting removed from Tony's chest. Moreover, at one point, Tony grabbed a handful of fresh snow and rubbed it across his left arm, which was clearly still bothering him. While fighting Aldrich Killian later in the movie, the left arm of Tony's suit was yanked off.
Avengers: Age of Ultron (2015)
In the MCU's second Avengers movie, the group faced off against Ultron and the Maximoff siblings before the pair ed the other side. Wanda, a.k.a. Scarlet Witch, used her powers of inflicting haunting visions, affecting the Avengers team. Bruce Banner then turned into the Hulk, wreaking havoc on the city. Tony tried to stop his friend using his special Hulkbuster suit. Hulk proved to be no match for Tony and ripped apart his armor, including the Hulkbuster's left appendage. Moreover, with Tony facing off against his own creation in Ultron, this movie remains a crucial point in Iron Man's MCU timeline.
Captain America: Civil War (2016)
Civil War, although sadly not one that spares Iron Man's left arm from the continuous abuse it has suffered.
Spider-Man: Homecoming (2017)
Tony's arm problem was very apparent in Spider-Man: Homecoming. Tony was a mentor to young Peter Parker, but the teenager wanted to prove himself as Spider-Man, so he targeted Vulture's illegal smugglers on his own. When he got into trouble, Tony had to send a suit to remotely save Peter while he was in India. During the India scene, the movie showed a close-up of Tony's arms, revealing that his left hand was shaking. When Tony encountered Peter directly following the ferry incident, he was still nursing his left arm and wrist.
Avengers: Infinity War (2018)
Comparatively, Tony Stark's left arm suffered very little in Star-Lord's big mistake, Tony was seemingly the last man standing. He used his booster, shield, and other nanotech powers — but it wasn't enough. Thanos destroyed much of the armor and trapped Tony's left arm. He then switched the armor covering his left arm to his right arm, forming a sword. Thanos answered by pulling off the sharp weapon and impaling Tony in the abdomen before escaping to Wakanda.
Avengers: Endgame (2019)
Despite the attention to Tony's left arm throughout the MCU, his right arm wound up sustaining the most damage during the character's final heroic moment. Tony helped build another gauntlet to house the Infinity Stones in the hope that if they obtain all six, they could undo the MCU event known as the "Decimation." The surviving of the Avengers faced off against Thanos and his army outside the Avengers compound. Tony managed to acquire the stones for his own gauntlet before snapping his fingers, decimating Thanos and his army. The energy from the gauntlet charred Tony's right hand before the injury spread throughout his body. For once, his left arm was left unscathed, but Iron Man's injuries proved to be too much and resulted in the character's infamous death.
Marvel What If...?
In Zombie Iron Man's left arm got partially munched, meaning that What If...? continues the legacy of left arm based Iron Man injuries. Furthermore, as What If...? is set within the MCU but in an alternate universe, "What If... Zombies?!" was the first and, so far, only appearance of Tony Stark in the Marvel Cinematic Universe after he sacrificed his life to defeat Thanos.
