Excessive tibial movement; demonstrated when supine patient flexes knee to 80¡Ð90¡ and hip to 45¡ and examiner medially rotates foot and pushes on tibia posteriorly. Positive finding indicates possible injury to posterior cruciate ligament, posterior oblique ligament, medial collateral ligament, semimembranosus muscle, posteromedial capsule, or anterior cruciate ligament.