Popliteus muscle

Popliteus muscle is a small, flat, triangular muscle located at the back of the knee. It is part of the posterior compartment of the leg and is the only muscle in this compartment that acts on the knee joint. The popliteus muscle is important for unlocking the knee from a fully extended position by laterally rotating the femur on the fixed tibia, or medially rotating the tibia.

Anatomy

The popliteus muscle originates from the lateral condyle of the femur and the posterior horn of the lateral meniscus. It then runs diagonally across the back of the knee joint and inserts into the posterior surface of the tibia above the soleal line. The muscle is supplied by the tibial nerve and receives blood supply from the popliteal artery.

Function

The main function of the popliteus muscle is to unlock the knee joint at the beginning of the flexion movement. When the knee is fully extended, the femur is medially rotated on the tibia to lock the joint. The popliteus muscle laterally rotates the femur on the tibia to unlock the joint. It also helps to stabilize the knee joint and control the rate of descent when walking downhill.

Clinical significance

Injury to the popliteus muscle can cause pain and swelling at the back of the knee, often referred to as popliteus tendonitis. This condition is commonly seen in runners and cyclists. Treatment usually involves rest, ice, compression, and elevation (RICE), along with physical therapy to strengthen the muscle and improve flexibility.

See also

• List of muscles of the human body
• Knee pain
• Tendonitis

Popliteus muscle

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  Posterior compartment of leg - popliteus muscle
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  Popliteus muscle by Sanjoy Sanyal
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  Popliteus large
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  Gray's Anatomy illustration of Musculus popliteus
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  Sobo 1909 illustration