What would indicate a positive Thompson test for the Achilles tendon?

• A. Inability to plantarflex the foot when the calf is squeezed
• B. Movement of the foot away from the body during dorsiflexion
• C. Excessive flexion of the toes during assessment
• D. Swelling around the Achilles tendon area

Answer: (A)

A positive Thompson test for the Achilles tendon is indicated by the inability to plantarflex the foot when the calf is squeezed. This test is performed by having the patient lie prone with their feet hanging off the edge of the examination table. The examiner then squeezes the calf muscle. If the Achilles tendon is intact, this action should trigger a reflexive plantarflexion of the foot due to the intact gastrocnemius and soleus muscles. If there is a rupture of the Achilles tendon, the foot will not move, demonstrating an abnormal response during the test. This directly assesses the integrity of the Achilles tendon and confirms its functionality.

The other options do not specifically relate to the mechanisms assessed by the Thompson test. The movement of the foot away from the body during dorsiflexion does not provide information about the tendon’s integrity, and excessive flexion of the toes or swelling around the Achilles tendon could suggest other types of injuries or conditions but would not specifically confirm a positive test outcome for the Achilles tendon via this method.