Patella articulates anteriorly as a sesamoid bone in the quadriceps tendon. Anterior cruciate ligament from lateral posterior femoral condyle to anterior aspect of tibial intercondyler eminence. Posterior cruciate ligament. Oblique popliteal and arcuate ligaments strengthen the posterior joint capsule. Flexion is primarily by the hamstrings, short head of biceps, gracilis, and sartorius.
Extension is primarily by the quadriceps and tensor fascia lata.
Medial rotation of tibia is primarily by popliteus, semitendonosus, gracilis, and sartorius. Abduction and adduction is limited by the medial and lateral collateral ligaments. In this case, the tibia is fixed by virtue of the planted foot. Thus, rotation of the knee occurs as movement of the femur. Notice that the lateral femoral condyle is smaller than the medial femoral condyle.