Which test assesses medial knee pain associated with the MCL?

• A. Varus stress test
• B. Valgus stress test
• C. Lachman test
• D. McMurray test

Answer: (B)

Valgus stress to the knee tests the MCL because this ligament resists forces that push the knee inward, or medially. When you apply a valgus force at the ankle with the thigh stabilized and the knee slightly flexed (about 20–30 degrees), the medial structures are stressed. A positive finding—pain along the medial joint line or increased medial laxity compared with the other side—points to an MCL injury. Testing at this angle helps isolate the MCL, whereas extension involves additional structures. By contrast, the other tests target different structures: a lateral stress test checks the LCL and lateral stabilizers; the Lachman test assesses the ACL with anterior tibial translation; and the McMurray test screens for meniscal tears through knee rotation and meniscal movement.