Although not a part of the knee joint, the articulation of the tibia and fibula is significant due to its importance in weight bearing. The patellofemoral joint is a synovial gliding type joint. The patella is a sesamoid bone contained in the tendon of the quadriceps muscle. The articulation consists of the underside of the patella and the patellar grove of the femur. The gliding of the patella in the femoral grove allows for increased efficiency of the quadriceps muscle.
Many muscles acting on the thigh have their insertions around the knee.
Although not participating in gross knee movements these muscles are significant in the dynamic stabilization of the knee joint. Only the muscles specifically participating in knee flexion, extension, internal, and external rotation are discussed here. The anterior muscles of the knee act primarily as knee extensors . The quadriceps femoris muscle is the principle muscle involved in knee extension. All four parts of this muscle come together to insert on the proximal edge of the patella, which then transfers their action, by way of the patellar tendon, to the tibia.