The Aperture Science Database Wiki
250px-Advanced Knee Replacement zoom

The Advance Knee Replacement closeup.

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


The device consists of two prosthesis 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. As the only seen Test Subject, Chell uses these prosthesis.