The Thompson test is commonly used to check for rupture of the Achilles tendon. Anatomy of the Achilles tendon The Achilles tendon is an extension of the calf muscles. The Achilles tendon inserts into the calcaneus. The Achilles tendon allows for plantar flexion of the ankle. Most Achilles tendon ruptures occur above the calcaneal insertion of the tendon. When the examiner squeezes the calf muscle, these should be the motion of the foot, which is a sign of an intact Achilles tendon. With a complete tear of the Achilles tendon, there will be no movement of the ankle when performing the Thompson test. Positive Thompson test: no movement of the foot- Achilles torn. The tendon is noticeably intact in the normal ankle compared to the ankle that has rupture of the Achilles tendon.