Popliteus muscle
Musculus popliteus
- Related terms: Popliteus
Definition
The popliteus muscle is a small, triangular muscle located in the posterior compartment of the knee. It originates from the lateral femoral condyle, the fibular head, and sometimes the lateral meniscus, and inserts onto the posterior surface of the proximal tibia above the soleal line. The popliteus forms part of the posterolateral corner of the knee and is situated deep to the gastrocnemius and plantaris muscles. Its tendon passes through the popliteal sulcus of the lateral femoral condyle before entering the joint capsule. The popliteus is responsible for initiating knee flexion by "unlocking" the knee—internally rotating the tibia relative to the femur—and contributes to posterolateral knee stability. It is innervatedby the tibial nerve and receives blood supply from branches of the inferior medial genicular from popliteal artery and posterior tibial arteries.
Origin: Middle facet of the lateral surface of the lateral femoral condyle
Insertion: Posterior tibia under the tibial condyles
Artery: Popliteal artery
Nerve: Tibial nerve
Action: Medial rotation and flexion of knee
Description: The Popliteus is a thin, flat, triangular muscle, which forms the lower part of the floor of the popliteal fossa. It arises by a strong tendon about 2.5 cm. long, from a depression at the anterior part of the groove on the lateral condyle of the femur, and to a small extent from the oblique popliteal ligament of the knee-joint; and is inserted into the medial two-thirds of the triangular surface above the popliteal line on the posterior surface of the body of the tibia, and into the tendinous expansion covering the surface of the muscle.
Variations.—Additional head from the sesamoid bone in the outer head of the Gastrocnemius. Popliteus minor, rare, origin from femur on the inner side of the Plantaris, insertion into the posterior ligament of the knee-joint. Peroneotibialis, 14 per cent., origin inner side of the head of the fibula, insertion into the upper end of the oblique line of the tibia, it lies beneath the Popliteus.
References
This definition incorporates text from a public domain edition of Gray's Anatomy (20th U.S. edition of Gray's Anatomy of the Human Body, published in 1918 – from http://www.bartleby.com/107/).
