The screw home mechanism is a movement of the joint that is key to keeping the knee stable while standing upright.

 

How the screw home works

It is a rotation between the tibia and femur occurring at the end of knee extension, between full extension (0 degrees) and 20 degrees of knee flexion.

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CLINICAL PUBLICATIONS

Screw-Home Movement of the Tibiofemoral Joint during Normal Gait: Three-Dimensional Analysis. Kim HY, Kim KJ, Yang DS, MD, Jeung SW, Choi HG and Choy WS. Clin Orthop Surg. 2015 Sep; 7(3): 303–309.