The knee joint is stabilized by several ligaments and muscles. The anterior (front) of the knee joint is covered by the kneecap, also called the patella, which floats inside the tendon and attaches the quadriceps to the lower leg. The front of the knee also is held by the tensor fascia latae and the muscles of the pes anserinus on either side. All together, there are eight muscles in these three groups.
Quadriceps Femoris
The quadriceps femoris is made up of four muscles with a common tendon that inserts into the tibial tuberosity of the lower leg. The word "quadriceps" means "four heads" and refers to the rectus femoris, the vastus intermedius, vastus medialis and the vastus lateralis. These four muscles join at the patellar tendon, which contains the kneecap, and inset into the front of the tibia.
Iliotibial Band
The iliotibial band (IT band) is the dense connective tissue on the outside of the thigh and knee. It is a large and very long tendon that attaches the hip to the lower leg and crosses the knee on the outside. The muscle of the IT band is the tensor fascia latae, which is located in the area of the hip.
Pes Anserinus
The pes anserinus is the tendon on the inner side of the knee and is the attachment of three muscles that cross the knee joint: the semitendinosis, gracilis and sartorius. All three join in the tendon (pes anserinus) that inserts on the inner portion of the tibia at the knee.
References
- "Gray's Anatomy: The Anatomical Basis of Clinical Practice"; Susan Standring (Editor); 2008
- "Trail guide to the body: How to locate muscles, bones and more"; Andrew Biel; 2005
