Posterior gliding of tibia on femur is prevented by –
**Question:** Posterior gliding of tibia on femur is prevented by -
**Core Concept:** In the lower limb, the posterior tibiofemoral joint is a hinge joint that allows flexion and extension movements of the knee. The primary function of this joint is to prevent posterior dislocation of the tibia.
**Why the Correct Answer is Right:** The correct answer, **Option C: Posterior cruciate ligament (PCL)**, plays a crucial role in preventing posterior gliding of the tibia on the femur at the tibiofemoral joint. The PCL is a strong, crossed ligament that runs from the medial condyle of the femur to the posterior aspect of the tibia.
**Why Each Wrong Option is Incorrect:**
A. **Option A: Anterior cruciate ligament (ACL)**: The ACL is a strong, crossed ligament that runs from the lateral condyle of the femur to the tibia's anterior aspect. It prevents anterior tibial translation and does not contribute to preventing posterior tibial gliding.
B. **Option B: Muscles**: While muscles contribute to overall joint stability, they alone cannot prevent posterior tibial gliding. Ligaments, like the PCL, provide the primary stability at the joint.
D. **Option D: Femoral condyles**: Femoral condyles are the rounded projections on the femur, not involved in preventing posterior tibial gliding. The primary stabilizers are the ligaments, like the PCL.
**Clinical Pearl:** The posterior tibiofemoral joint stability relies on the combined actions of the PCL, ACL, and the surrounding muscles. Any injury to these stabilizing structures can lead to instability and potential dislocation. Understanding the specific roles of these structures is essential for clinical practice and patient management.