When horror movie fans think of Misery, they often think of one particularly grueling moment — the infamous hobbling scene. Even more impressively, Kathy Bates' ankle shattering-moment was done without the help of CGI. Here's how director Rob Reiner pulled it off.

The Stephen King adaption tells the story of former nurse Annie Wilkes (Bates) after she rescued a man from a serious car crash. That man happens to be Annie's favorite author, Paul Sheldon (James Caan). She vows to take care of Paul as he recovers, but once she discovers he plans to kill off her favorite character, things take a turn for the worst. Annie becomes obsessive and turns to violence in order to persuade Paul to change his mind about the character's death.

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One of the violent strategies she deploys is hobbling. Annie keeps Paul tied up in a bed, so he's unable to escape. At one point in the film, she approaches him with a sledgehammer and begins to describe the act of hobbling. She explains workers who stole diamonds were punished by being hobbled. It sent a clear message to the workers without killing them. Annie then proceeds to place a wood block between each of his feet and smashes each of his ankles with the sledgehammer. Here's how this effect was done without CGI.

In order to pull off the horrific act of hobbling in Misery, Reiner hired special effects makeup team KNB EFX Group to create prosthetic versions of Caan's legs. The prosthetics were created with a combination of gelatin and PVC pipe with hinges in the ankles. Bates used a real sledgehammer in the scene, so hitting the ankles with enough force caused them to bend at a horrifying angle. Reiner made to have the camera tightly follow Annie's sledgehammer as it came down on Paul's ankles. That camera angle stayed so tightly focused on the prosthetic legs that, as Yahoo reported, Caan was able to leave the bed while the hobbling scene was filmed.

Reiner actually toned down the hobbling scene for his adaptation of Misery. The hobbling scene was more brutal in King's book; Annie went so far as to cut off one of Paul's feet with an ax and immediately cauterize the wound with a propane torch. Reiner dialed back the graphic nature of the scene to ensure Paul would emerge victorious at the end of the film, but he also made the choice in order to ensure that the movie wasn't too gory.

Horror movies often have to walk a tightrope when it comes to the level of violence they put on screen. Too little and it's not scary enough to give audiences the thrill they seek in watching horror movies. Too much and it comes off as torture porn. Reiner found the perfect balance in Misery. The act was horrendous, but not so much that a typical horror movie fan would have to avert their eyes. It's this perfect balance that made Misery go down in history as one of the most memorable horror movie scenes of all time.

More: How Stephen King’s Real Life Inspired Misery In Surprising Ways