Popliteus Tendinitis Anatomy
To better understand popliteus tendinitis, it helps to understand the anatomy of the knee joint.
Four bones come together at the knee joint:
- Thin bone on the side of the lower leg
The tibia supports all of the body's weight below the knee joint. The tibia and femur form the major portion of the knee joint, and the patella protects the front of the knee.
Bones of the knee:
The main tendons in knee include:
- Quadriceps tendon: attaches the quadriceps muscle to the kneecap
- Patellar tendon: attaches the patella to the tibia
- Popliteus tendon: extends from the outer bottom surface of the femur and travels diagonally behind the knee to attach to the inner upper surface of the tibia.
- Hamstring tendons: attach the hamstring muscles to the tibia
- Calf tendons: attach the calf muscles to the femur
Strong fibrous bands, called ligaments, support the knee. Injuries to the knee ligaments are common.
The knee ligaments include:
- Lateral collateral ligament: stabilizes the knee from stress applied to the sides of the knee
- Medial collateral ligament: stabilizes the knee from stress applied to the sides of the knee
- Posterior cruciate ligament: stabilizes the knee from stress applied to the front or back of the knee
- Anterior cruciate ligament: stabilizes the knee from stress applied to the front or back of the knee
Cartilage is a very smooth, firm layer of tissue that lines all of the joints in the body. Two discs of cartilage, called the medial meniscus, and lateral meniscus, line the inside of the knee. Torn cartilage refers to an injury to a meniscus.
- Bailey MP, Maillardet FJ, Messenger N. Kinematics of cycling in relation to anterior knee pain and patellar tendinitis. J Sports Sci. 2003 Aug;21(8):649-57. 
- Bennett R. Addressing musculoskeletal pain. Geriatrics. 2004 Aug;59(8):11-2. 
- Richards DP, Ajemian SV, Wiley JP, Zernicke RF. Knee joint dynamics predict patellar tendinitis in elite volleyball players. Am J Sports Med. 1996 Sep-Oct;24(5):676-83.