Which muscle unlocks the knee joint?

Unlock all questions

This demo includes only 20 questions. Upgrade to access hundreds of questions, flashcards, exam simulations, and disable ads.

Full question bankExam simulationsFlashcards
From $25.99Unlock all

Discover high-yield NBME Gross Anatomy concepts with quizzes designed to enhance your understanding. Equip yourself with flashcards, multiple-choice questions, and detailed explanations. Prepare effectively for your anatomy exam!

Multiple Choice

Which muscle unlocks the knee joint?

Explanation:
Unlocking the knee relies on the popliteus. When the knee is extended, the joint is effectively locked by a lateral rotation of the tibia relative to the femur (the screw-home mechanism). The popliteus contracts to initiate flexion by rotating the tibia medially on the femur (or, with the thigh fixed, by rotating the femur laterally), releasing that lock and allowing the knee to bend. The muscle’s fibers originate from the lateral femoral condyle and insert on the posterior tibia, placing it perfectly to produce this medial rotation and unlock the joint. This specific action is why it’s the correct choice.

Unlocking the knee relies on the popliteus. When the knee is extended, the joint is effectively locked by a lateral rotation of the tibia relative to the femur (the screw-home mechanism). The popliteus contracts to initiate flexion by rotating the tibia medially on the femur (or, with the thigh fixed, by rotating the femur laterally), releasing that lock and allowing the knee to bend. The muscle’s fibers originate from the lateral femoral condyle and insert on the posterior tibia, placing it perfectly to produce this medial rotation and unlock the joint. This specific action is why it’s the correct choice.

More Multiple Choice Questions
Subscribe

Get the latest from Passetra

You can unsubscribe at any time. Read our privacy policy