Which test is listed as a knee ACL test in the material?

• A. McMurray test
• B. Varus stress test
• C. Lachman's test
• D. Anterior drawer test

Answer: (C)

Lachman’s test directly assesses ACL integrity by testing how much the tibia can translate forward relative to the femur with the knee in about 20–30 degrees of flexion. Because the knee is not fully flexed, the hamstrings are less able to mask an ACL tear, so excessive anterior translation and a soft end feel indicate a positive result. This makes Lachman’s test the most sensitive single test for detecting an ACL tear in the clinical setting. The other tests serve different purposes: McMurray checks for meniscal tears with rotational movements; Varus stress test targets the lateral collateral ligament and lateral structures; and the anterior drawer test also looks at ACL laxity but at 90 degrees of flexion, where guarding and positioning can reduce sensitivity. Hence, Lachman’s test is the knee ACL test listed.