Advanced Knee Replacement

{{Technology Infobox
|image=FileAdvanced Knee Replacement zoom.jpg|250px
|name=Advanced Knee Replacement
|affiliation=Aperture Science
|type=Prosthetic heel springs
{{Quote|Ewww, what's wrong with your legs?|GLaDOS' Aperture Science Personality Construct Core|Curiosity Core|Portal|Fileescape_02_sphere_curiosity-08.ogg}}

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

*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.''Portal 2 Lab Rat'' After being awoken again by Wheatley, she donned Long Fall Boots instead.

==Behind the scenes==
FileAssassin springs.jpg|thumb|200px|Detail of the Combine Assassin's heel springs.

*The Advanced Knee Replacement was added to ''Portal'' due to disbelief by playtesters that Chell could survive the drops she was subject to, particularly those that involved falling recursively through ''Portal.html">Teleportation|portals.''Portal'' commentary The ''Portal'' trailer, "http// Orientation Video no. 1", predates this development phase, as it states that jumping from high ledges is fatal if a portal is not below. 

*The Advanced Knee Replacement design was recycled from that of the Combine Assassin's heel springs, the female Combine unit cut from ''Half-Life 2''.Development of Half-Life 2 game|''Half-Life 2'' leak

*According to http//,42252/ 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,http// Redesigning Portal Valve’s Artist Speaks on Game Informer until they decided to replace it with a variant, the Long Fall Boot.

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

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


FileJumping from high ledges.jpg|Diagram showing what happens when a Test Subject jumps without the Advanced Knee Replacement.
FileChell-back.jpg|Chell and her Advanced Knee Replacements from the back.
FileChell-walk.jpg|Front view.
FileAperture clipboard Knee.png|Clipboard sheet featuring the Advanced Knee Replacement specs.
FileTwo clipboards.jpg|Two clipboards in an Aperture Laboratories office, including one about the Advanced Knee Replacement.

===''Portal 2''===

FilePotato 76.jpg|Concept art for different Advanced Knee Replacement iterations, revealed during the PotatoFoolsDay ARG|''PotatoFoolsDay'' ARG. Several of these designs would be the basis for the Long Fall Boot that would later be used in ''Portal 2''.
FilePotato 77.jpg|Two early Advanced Knee Replacement models, also revealed during the ''PotatoFoolsDay'' ARG.
FileChell model early views.jpg|Views of an early render of the ''Portal 2'' Chell model, with Advanced Knee Replacement.
FileChell model views portal 2.jpg|Views of Chell's ''Portal 2'' model, with Advanced Knee Replacement.
FileChell dragged.jpg|Chell's Advanced Knee Replacement is destroyed as the Party Escort Bot drags her back into the facility.
FilePotato 61.jpg|Outfit study for Chell on a picture of Alésia Glidewell, revealed during the ''PotatoFoolsDay'' ARG, featuring several Advanced Knee Replacement iterations.
FileMel model.jpg|Pink Advanced Knee Replacement on Mel's placeholder model.

==List of appearances==
*''Portal'' {{1st}}
*''Portal First Slice''
*''Portal Still Alive'' {{Nc}}
*PotatoFoolsDay ARG|''PotatoFoolsDay'' ARG
*''Portal 2 Lab Rat''
*''The Final Hours of Portal 2''

== See also ==
* Long Fall Boot


CategoryAperture Science technology
CategoryCombine technology
CategoryHalf-Life 2 (pre-release)
CategoryPortal 2 Lab Rat