Todays_Physio on Instagram: "Special Test for Knee Joint: Lachman Test Explained! The Lachman Test is one of the most reliable clinical tests used to assess the integrity of the ACL (anterior cruciate ligament) in the knee. It's especially useful for detecting ACL tears. How it's done: The patient lies down with the knee flexed at about 20-30°. The examiner stabilizes the femur with one hand and pulls the tibia forward with the other. Excessive forward movement or a soft end feel suggests an ACL