What keeps the femur from slipping backward off the tibia?

Answer 1

1. The posterior cruciate ligament (PCL) keeps the femur(thighbone) from slipping off the tibia (shinbone), because it connects to both from the back.

Answer 2

The posterior cruciate ligament (PCL) is considered the primary structure that prevents posterior displacement of the tibia on the femur.

Note that all of the structures associated with the knee play some role in stability, muscles, ligaments, capsule, etc. But, the PCL is primary for the role described in the question.

Answer 3

The stabilizing factors that prevent the femur from slipping backward off the tibia during movements include the shape of the knee joint surfaces, the surrounding ligaments, such as the posterior cruciate ligament, and the muscles and tendons that support and maintain proper alignment of the knee joint. These structures work together to provide stability and prevent displacement of the bones during activities.