Advanced Knee Replacement

"Ewww, what's wrong with your legs?"

- GLaDOS's Curiosity Core

The Advanced Knee Replacement is a technique used by Aperture Science to prevent Test Subjects from injury from huge drops by lessening the impact.

Overview

 * The device consists of two prostheses completely or partially replacing the knee, partially tied to the Test Subject's calves, and prolonged with two flexible curved pieces of metal going under the Test Subject's heels, acting as springs.


 * Before being first awoken, Chell had been fitted with Advanced Knee Replacement, which was destroyed when she got dragged by the Party Escort Bot after she defeated GLaDOS. After being awoken again by Wheatley, she donned Long Fall Boots instead.

Behind the scenes



 * The heel springs were originally created for the Combine Assassin, cut from Half-Life 2.


 * The Advanced Knee Replacement was added into Portal due to disbelief by playtesters that Chell could survive the drops she was subject to, particularly those that involved falling recursively through portals.


 * According to Matt Charlesworth, the team was not sure whether to keep the Advanced Knee Replacement in Portal 2. He stated that some team members were attached to it, and that some were not, so they experimented what to do with them, or how to replace them, until they decided to replace it with a variant, the Long Fall Boot.


 * According to the diagram about jumping from high ledges shown in Orientation Video no. 1 and to Doug Rattmann's appearance in Portal 2: Lab Rat, the Advanced Knee Replacement was made exclusively for Chell or for certain Test Subjects.

Trivia

 * The real-life corollary activity to this is called "powerbocking". A very similarly shaped device is also used as prosthetic legs for amputees (such as Eli Vance's).


 * The sound files for the Advanced Knee Replacement footsteps use the name "future shoes".

List of appearances

 * Portal
 * Portal: First Slice
 * Portal: Still Alive
 * Portal 2: Lab Rat