The pivot shift test is sensitive only in a fully relaxed patient. The test is performed with the knee starting in extension. The clinician holds the lower leg with one hand and internally rotates the tibia, while placing a valgus stress on the knee using the other hand. While maintaining the forces described, the clinician flexes the knee. In the ACL-deficient knee this causes a reduction of the subluxed tibia, which the clinician senses as a 'clunk,' and which constitutes a positive test.