Valgus Varus Stress Test:These tests attempt to reveal instability to medial or lateral displacement within the knee.

The valgus test involves placing the leg into extension, with one hand placed as a pivot on the knee. With the other hand placed upon the foot applying an abducting force, an attempt is then made to force the leg at the knee into valgus. If the knee is seen to open up on the medial side, this is indicative of medial ligament and / or cruciate ligament damage.

The varus test involves applying forces to the knee in the opposite direction. Widening of the joint on the lateral side is indicative of lateral ligament and / or posterior cruciate ligament deficiencies.

Variations of these tests involve placing the knee in varying amounts of flexion and rotation.