Knee Joint Muscles
The knee joint consists of the femur (thigh bone), tibia and fibula with the patella or kneecap. Muscles producing joint actions at the knee joint are the quadriceps muscles (vastus medialis, vastus lateralis, vastus intermedius and rectus femoris at the front, with the hamstring muscles (semitendinosis, semimembranosus and biceps femoris) at the back along with the popliteus muscle.
The hamstring muscles at the back of the thigh consist of the biceps femoris, semitendinosus and semimembranosus.
Vastus Medialis is the most medially (inner) located of the quadricep muscles. The portion of the muscle just above the knee is known as VMO (vastus medialis oblique). This is important in stabilising the knee joint and often becomes inhibited following injury.